FAO Manual on Meat Inspection for Developing Countries PDF

Manual on meat inspection for developing countries FAO ANIMAL PRODUCTION AND HEALTH PAPER 119 Manual on meat inspection for...

Manual on meat inspection for developing countries FAO ANIMAL PRODUCTION AND HEALTH PAPER 119 Manual on meat inspection for developing countries CONTENTS by D. Herenda in cooperation with P.G. Chambers A. Ettriqui P. Seneviratna T.J.P. da Silva Reprinted 2000 The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. M-25 ISBN 92-5-103304-8 http://www.fao.org/docrep/003/t0756e/t0756e00.htm (1 of 13)10/17/2005 8:01:42 PM Manual on meat inspection for developing countries All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to the Chief, Publishing and Multimedia Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to copyright @fao.org Food and Agriculture Organization of the United Nations Rome, 1994 © FAO Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics. CONTENTS ACKNOWLEDGEMENTS INTRODUCTION CHAPTER 1. MEAT INSPECTION PROCEDURES Antemortem and postmortem inspection of food animals - General Principles Antemortem Inspection Postmortem Inspection - carcass judgement - localized versus generalized conditions - acute versus chronic conditions Guidelines for minimum postmortem inspection requirements of heads for cattle, horses, sheep and goats, pigs and game Guidelines for minimum postmortem inspection requirements of viscera for cattle, horses, sheep and goats, pigs and game http://www.fao.org/docrep/003/t0756e/t0756e00.htm (2 of 13)10/17/2005 8:01:42 PM Manual on meat inspection for developing countries Guidelines for minimum postmortem inspection requirements of carcass for cattle, horses, sheep and goats, pigs and game Antemortem and postmortem inspection of poultry Slaughter and inspection of game animals for meat Slaughter and inspection of farmed game Slaughter and inspection of ostriches Supervision of hygienic dressing of carcasses Hazard Analysis Critical Control Point (HACCP) Concept in Meat Inspection CHAPTER 2. GENERAL PATHOLOGICAL CONDITIONS Fever Inflammation in viral diseases Septicemia Toxaemia Pigmentation (A) Melanosis (B) Myocardial lipofuscinosis (C) Congenital porphyria (D) Icterus (Jaundice) Haemorrhage and Haematoma Bruises Abscess Emaciation Edema Emphysema Tumours or neoplasms Calcification http://www.fao.org/docrep/003/t0756e/t0756e00.htm (3 of 13)10/17/2005 8:01:42 PM Manual on meat inspection for developing countries Degeneration Telangiectasis Abnormal odours Immaturity Plant poisoning Chemical poisoning Spear grass penetration of sheep CHAPTER 3. SPECIFIC DISEASES OF CATTLE Diseases caused by viruses Foot and Mouth Disease (FMD, Aphthous fever) Rinderpest (RP) Vesicular stomatitis (VS) Malignant catarrhal fever (MCF) Rift valley fever (RVF) Rabies Lumpy skin disease Bovine herpes demophathic disease (BHD) Infectious bovine rhinotracheitis (IBR) Bovine viral diarrhoea (BVD) Bovine leukosis Bovine spongiform encephalopathy (BSE, “Mad cow disease”) Diseases caused by Rickettsia and Mycoplasma spp. Heartwater (Hydropericardium, “Black dung”) Q fever (Queensland fever, Nine mile fever) Contagious bovine pleuropneumonia Diseases caused by bacteria http://www.fao.org/docrep/003/t0756e/t0756e00.htm (4 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Black quarter (Black leg) Botulism Malignant edema Tuberculosis Johne's disease (Bovine paratuberculosis) Leptospirosis Brucellosis (Contagious abortion, Bang's disease) Anthrax Salmonellosis in bovine Haemorrhagic septicemia Calf diphtheria Actinobacillosis Actinomycosis Pyelonephritis (Contagious Bovine Pyelonephritis) Metritis Mastitis Endocarditis Traumatic reticuloperitonitis (TRP, Hardware disease) Parasitic diseases Diseases caused by helminths Lung worms Fascioliasis Dicrocoelium dendriticum infection Oesophagostomiasis (Pimply gut, Nodular worms) Cysticercosis Hydatid disease http://www.fao.org/docrep/003/t0756e/t0756e00.htm (5 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Onchocercosis Parafilariasis Diseases caused by protozoa Trypanosomiasis Theileriosis (East cost fever) Besnoitiosis Anaplasmosis (Hallsickness) Babesiosis (Piroplasmosis, Texas fever, Red water, Tick fever) Sarcosporidiosis Diseases caused by arthropod parasites Hypoderma bovis infestation Screwworm Myiasis CHAPTER 4. SPECIFIC DISEASES OF PIGS Diseases caused by viruses African Swine Fever (ASF) Foot and Mouth Disease (FMD) Hog cholera Vesicular exanthema of swine (VES) Swine vesicular disease (SWD) Vesicular stomatitis Transmissible gastroenteritis (TGE) Diseases caused by bacteria Pneumonia Pleuritis Valvular endocarditis in pigs Porcine chronic pericarditis http://www.fao.org/docrep/003/t0756e/t0756e00.htm (6 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Tuberculosis Porcine brucellosis Porcine salmonellosis Swine erysipelas Melioidosis Anthrax Parasitic diseases Diseases caused by helminths Trichinosis Cysticercosis (Cysticercus cellulosae infestation) Ascariasis Sparganosis Diseases caused by protozoa Porcine Babesiosis (Piroplasmosis) Sarcocystosis in pigs (Sarcosporidiosis) Toxoplasmosis Miscellaneous conditions Porcine stress syndrome (PSS) CHAPTER 5. SPECIFIC DISEASES OF SHEEP AND GOATS Diseases caused by virsues Rift valley fever (RVF) Contagious ecthyma (Contagious pustular dermatitis, Orf) Bluetongue (BT, catarrhal fever of sheep, “soremuzzle disease”) Sheep and goat pox Scrapie Pulmonary adenomatosis (Jaagsiekte, Driving sickness) http://www.fao.org/docrep/003/t0756e/t0756e00.htm (7 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Ovine progressive interstitial pneumonia (Maedi, Maedi-visna) Nairobi sheep disease Diseases caused by Mycoplasma spp. Contagious caprine pleuropneumonia Diseases caused by bacteria Brucellosis Black quarter (Black leg) Enterotoxaemia (Pulpy kidney) Infectious necrotic hepatitis (Black disease) Caseous lymphadenitis Parasitic diseases Diseases caused by helminths Coenurus cerebralis (Gid, Sturdy) Echinococcosis (Hydatid disease) Lung worms Fascioliasis Cysticercus tenuicolis Cysticercus ovis (sheep bladder worm) Stilesia hepatica Diseases caused by protozoa Babesiosis (Piroplasmosis, Texas fever, Red water, Tick fever) Toxoplasmosis Theileriosis in sheep and goats Sarcocystosis in sheep (Sarcosporidiosis) CHAPTER 6. SPECIFIC DISEASES OF HORSES Diseases caused by viruses http://www.fao.org/docrep/003/t0756e/t0756e00.htm (8 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries African horse sickness (AHS) Equine infectious anaemia Viral encephalomyelitis of horses Diseases caused by bacteria Contagious equine metritis (CEM) Tetanus Glanders Strangles (Distemper) Parasitic diseases Diseases caused by protozoa Trypanosomiasis (Dourine, Mal du coit) CHAPTER 7. SPECIFIC DISEASES OF POULTRY Diseases caused by viruses and chlamydia Avian influenza (AI) Newcastle disease (NCD) Infectious bronchitis (IB) Laryngotracheitis (LT) Fowl Pox (Pox, Avian Pox) Avian leucosis complex Lymphoid leucosis Marek's disease Ornithosis (Psittacosis, Avian chlamydiosis) Diseases caused by bacteria Salmonellosis Fowl typhoid Paratyphoid infection http://www.fao.org/docrep/003/t0756e/t0756e00.htm (9 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Arizona infection Fowl cholera (Pasteurellosis) Tuberculosis Chronic respiratory disease (CRD), “Air sacs disease” Parasitic diseases Diseases caused by protozoa Histomoniasis (Enterohepatitis or Blackhead) Coccidiosis CHAPTER 8. SPECIFIC DISEASES OF RABBITS Diseases caused by bacteria Pasteurellosis (Snuffles, pneumonia) Parasitic diseases Diseases caused by helminths Tape worm larvae in rabbits Diseases caused by protozoa Coccidiosis ACKNOWLEDGEMENT The principal author of this publication is Dr. D. Herenda, Veterinary Meat Inspection Expert, Toronto/Canada, who undertook the difficult task of describing diseases and pathological lesions of importance to slaughter animals in developed and developing countries. He was assisted in this task by the following veterinary experts: Dr P.G. Chambers, Bulawayo/Zimbabwe covering the African Region Dr. P. Seneviratna, Canberra/Australia covering the Asian/Pacific Region Prof. Dr. T.J. da Silva, Belo Horizonte/Brazil covering the Latin American/Caribbean Region http://www.fao.org/docrep/003/t0756e/t0756e00.htm (10 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries and Prof. Dr. A. Ettriqui, Sidi Thabet/Tunisia covering the Near East Region. The contributions by the co-authors were incorporated into the main text by Dr. Herenda. The publication was planned, coordinated and edited by Dr. G. Heinz and K. Amamoto of the Meat and Dairy Service of FAO's Animal Production and Health Division. The illustrations reproduced in the book were contributed by the following institutions or persons: Animal and Plant Health and Inspection Services (APHIS) and the Food Safety and Inspection Services (FSIS) of the United States Department of Agriculture: Fig. 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 64, 65, 86, 114, 115, 116, 117, 118, 119, 120, 121, 122, 149, 150, 153, 155, 156, 157, 179, 180, 181, 184, 185, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 200, 201, 203, 204, 212. Canada Department of Agriculture: Fig. 62, 73, 138, 152, 154, 183. Mosby Year-Book Inc. St. Louis Mo., USA: Fig. 21, 30, 34, 35, 36, 37, 41, 111, 112. Department of Clinical Medicine, University of Guelph, Guelph, Ontario, Canada: Fig. 186. Department of Population Medicine, University of Guelph, Ontario, Canada: Fig. 123, 124, 125, 126. Dr. J. Thorsen, Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario, Canada: Fig. 63, 96, 99, 100, 161. Pathology Department, University of Guelph, Guelph, Ontario, Canada: Fig. 58, 66, 103, 158, 163, 176, 177, 182, 202, 205, 208, 209, 210. Dr. Jerry Zaugg, Caine Veterinary Teaching Center, University of Idaho, Animal and Veterinary Science Department: Fig. 97, 104. Dr. P. Masztis, Weston Veterinary Clinic, Weston, Ontario, Canada: 19. Dr. G.J. Jackson, Division of Microbiology, FDA, Washington, DC: Fig. 90, 105, 137, 147. Dr. M. Vargas-Teram, FAO: Fig. 112A, 112B, 112C together with the contribution on Screwworm-Myiasis. http://www.fao.org/docrep/003/t0756e/t0756e00.htm (11 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries Dr. P.G. Chambers (Co-author): Fig. 28, 32, 33, 42, 44, 49, 68, 69, 88, 91, 93, 95, 98, 109, 113, 141, 142. Dr. P. Seneviratna (Co-author): Fig. 17, 18, 92, 94, 106, 108, 136, 145, 146, 148, 168, 173, 174, 178, and Table 1, 2. Dr. T. J. da Silva (Co-author): Fig. 67, 159. Dr. A. Ettriqui (Co-author): Fig. 162, 167. Dr. D. Herenda (Author): Fig. 1, 2, 4, 3, 5, 6, 7, 8, 9, 11, 12, 14, 10, 13, 16, 20, 22, 23, 25, 26, 27, 29, 31, 38, 39, 40, 57, 60, 61, 70, 71, 72, 75,.76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 87, 89, 107, 127, 128, 129, 130, 132, 133, 134, 135, 140, 143, 144, 160, 165, 166, 170, 171, 172, 175, 206, 207, 211, 213. Introduction Meat inspection is commonly perceived as the sanitary control of slaughter animals and meat. The aim of meat inspection is to provide safe and wholesome meat for human consumption. The responsibility for achieving this objective lies primarily with the relevant public health authorities who are represented by veterinarians and meat inspectors at the abattoir stage. In many developing regions and in particular in rural abattoirs, meat inspectors often lack the necessary information and guidelines to assess the sanitary status of carcasses, meat and organs from slaughter animals. FAO has therefore endeavoured to prepare concise guidelines on the subject together with colour illustrations demonstrating the pathological lesions that may occur in bovines, small ruminants, pigs, game, poultry and rabbits. The statements made on the judgement of diseased carcasses or parts of the carcasses are recommendations which are also influenced by the need of salvaging as much meat as possible for human consumption. These recommendations are not meant to interfere with any existing regulations on the subject in individual countries. This Manual on Meat Inspection for Developing Countries has been prepared by an experienced meat inspection specialist as the main author in cooperation with meat inspection experts from the four regions Asia and Pacific, Africa, Latin America and the Near East. The book is intended to guide meat inspectors particularly in the four mentioned regions in their daily work in urban and rural abattoirs. Veterinarians engaged in meat inspection will also benefit, especially as regards their supervisory roles in meat hygiene. The book shall also serve as a training manual for trainees in meat inspection, a field in which FAO has organized theoretical and practical training courses for many years. FAO will continue these activities in future and it is expected that the Manual will facilitate these http://www.fao.org/docrep/003/t0756e/t0756e00.htm (12 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries tasks. The Code of Hygienic Practice for Fresh Meat and the Codes for Anti-Mortem and Post- Mortem Inspection of Slaughter Animals published recently by the Joint FAO/WHO Codex Alimentarius Commission is a useful supplement to this publication and provides additional information on meat hygiene and inspection procedures. http://www.fao.org/docrep/003/t0756e/t0756e00.htm (13 of 13)10/17/2005 8:01:43 PM Manual on meat inspection for developing countries CHAPTER 1 MEAT INSPECTION PROCEDURES The objectives of meat inspection programme are twofold: a. To ensure that only apparently healthy, physiologically normal animals are slaughtered for human consumption and that abnormal animals are separated and dealt with accordingly. b. To ensure that meat from animals is free from disease, wholesome and of no risk to human health. These objectives are achieved by antemortem and postmortem inspection procedures and by hygienic dressing with minimum contamination. Whenever appropriate the Hazard Analysis Critical Control Point (HACCP) principles should be used: The inspection procedures should be appropriate to the spectrum and prevalence of diseases and defects present in the particular class of livestock being inspected using the principles of risk assessment. ANTEMORTEM AND POST MORTEM INSPECTION OF FOOD ANIMALS GENERAL PRINCIPLES Antemortem Inspection Some of the major objectives of antemortem inspection are as follows: to screen all animals destined to slaughter. to ensure that animals are properly rested and that proper clinical information, which will assist in the disease diagnosis and judgement, is obtained. to reduce contamination on the killing floor by separating the dirty animals and condemning the diseased animals if required by regulation. to ensure that injured animals or those with pain and suffering receive emergency slaughter and that animals are treated humanely. to identify reportable animal diseases to prevent killing floor contamination. to identify sick animals and those treated with antibiotics, chemotherapeutic agents, insecticides and pesticides. to require and ensure the cleaning and disinfection of trucks used to transport livestock. Both sides of an animal should be examined at rest and in motion. Antemortem examination should be done within 24 hours of slaughter and repeated if slaughter has been delayed over a day. Spread hogs and animals affected with extensive bruising or fractures require emergency slaughter. Animals showing clinical signs of disease should be held for veterinary examination and judgement. They are treated as “suspects” and should be segregated from the healthy animals. The disease and management history should be recorded and reported on an A/M inspection card. Other information http://www.fao.org/docrep/003/t0756e/T0756E01.htm (1 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries should include: 1. Owner's name 2. The number of animals in the lot and arrival time 3. Species and sex of the animal 4. The time and date of antemortem inspection 5. Clinical signs and body temperature if relevant 6. Reason why the animal was held 7. Signature of inspector Antemortem inspection should be carried out in adequate lighting where the animals can be observed both collectively and individually at rest and motion. The general behaviour of animals should be observed, as well as their nutritional status, cleanliness, signs of diseases and abnormalities. Some of the abnormalities which are checked on antemortem examination include: 1. Abnormalities in respiration 2. Abnormalities in behaviour 3. Abnormalities in gait 4. Abnormalities in posture 5. Abnormalities in structure and conformation 6. Abnormal discharges or protrusions from body openings 7. Abnormal colour 8. Abnormal odour Abnormalities in respiration commonly refer to frequency of respiration. If the breathing pattern is different from normal the animal should be segregated as a suspect. Abnormalities in behaviour are manifested by one or more of the following signs: The animal may be: a. walking in circles or show an abnormal gait or posture b. pushing its head against a wall c. charging at various objects and acting aggressively d. showing a dull and anxious expression in the eyes An abnormal gait in an animal is associated with pain in the legs, chest or abdomen or is an indication of nervous disease. Abnormal posture in an animal is observed as tucked up abdomen or the animal may stand with an extended head and stretched out feet. The animal may also be laying and have its head turned along its side. When it is unable to rise, it is often called a “downer”. Downer animals should be handled with caution in order to prevent further suffering. Abnormalities in structure (conformation) are manifested by: a. swellings (abscesses) seen commonly in swine b. enlarged joints c. umbilical swelling (hernia or omphalophlebitis) http://www.fao.org/docrep/003/t0756e/T0756E01.htm (2 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries d. enlarged sensitive udder indicative of mastitis e. enlarged jaw (“lumpy jaw”) f. bloated abdomen Some examples of abnormal discharges or protrusions from the body are: a. discharges from the nose, excessive saliva from the mouth, afterbirth b. protruding from the vulva, intestine c. protruding from the rectum (prolapsed rectum) or uterus d. protruding from the vagina (prolapsed uterus) e. growths on the eye and bloody diarrhoea Abnormal colour such as black areas on horses and swine, red areas on light coloured skin (inflammation), dark blue areas on the skin or udder (gangrene). An abnormal odour is difficult to detect on routine A/M examination. The odour of an abscess, a medicinal odour, stinkweed odour or an acetone odour of ketosis may be observed. Since many abattoirs in developing countries have not accommodation station or yards for animals, Inspector's antemortem judgement must be performed at the admission of slaughter animals. Postmortem inspection Routine postmortem examination of a carcass should be carried out as soon as possible after the completion of dressing in order to detect any abnormalities so that products only conditionally fit for human consumption are not passed as food. All organs and carcass portions should be kept together and correlated for inspection before they are removed from the slaughter floor. Postmortem inspection should provide necessary information for the scientific evaluation of pathological lesions pertinent to the wholesomeness of meat. Professional and technical knowledge must be fully utilized by: 1. viewing, incision, palpation and olfaction techniques. 2. classifying the lesions into one of two major categories - acute or chronic. 3. establishing whether the condition is localized or generalized, and the extent of systemic changes in other organs or tissues. 4. determing the significance of primary and systemic pathological lesions and their relevance to major organs and systems, particularly the liver, kidneys, heart, spleen and lymphatic system. 5. coordinating all the components of antemortem and postmortem findings to make a final diagnosis. 6. submitting the samples to the laboratory for diagnostic support, if abattoir has holding and refrigeration facilities for carcasses under detention. Carcass judgement Trimming or condemnation may involve: 1. Any portion of a carcass or a carcass that is abnormal or diseased. 2. Any portion of a carcass or a carcass affected with a condition that may present a hazard to human health. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (3 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries 3. Any portion of a carcass or a carcass that may be repulsive to the consumer. Localized versus generalized conditions It is important to differentiate between a localized or a generalized condition in the judgement of an animal carcass. In a localized condition, a lesion is restricted by the animal defense mechanisms to a certain area or organ. Systemic changes associated with a localized condition may also occur. Example: jaundice caused by liver infection or toxaemia following pyometra (abscess in the uterus). In a generalized condition, the animal's defense mechanisms are unable to stop the spread of the disease process by way of the circulatory or lymphatic systems. The lymph nodes of the carcass should be examined if pathological lesions are generalized. Some of the signs of a generalized disease are: 1. Generalized inflammation of lymph nodes including the lymph nodes of the head, viscera and/or the lymph nodes of the carcass 2. Inflammation of joints 3. Lesions in different organs including liver, spleen kidneys and heart 4. The presence of multiple abscesses in different portions of the carcass including the spine of ruminants Generalized lesions usually require more severe judgement than localized lesions. Acute versus chronic conditions Acute conditions An acute condition implies that a lesion has developed over a period of some days, whereas a chronic condition implies the development of lesions over a period of some weeks, months or years. A subacute condition refers to a time period between an acute and chronic condition. The acute stage is manifested by inflammation of different organs or tissues, enlarged haemorrhagic lymph nodes and often by petechial haemorrhage of the mucosal and serous membranes and different organs such as heart, kidney and liver. An acute stage parallels with the generalized disease complex, when an acute infection tends to overcome the animal's immune system and becomes generalized. Each case showing systemic lesions should be assessed individually taking into account the significance that these lesions have towards major organ systems, especially the liver, kidneys, heart, spleen and lymphatic system as well as the general condition of the carcass. Chronic conditions In a chronic condition, inflammation associated with congestion is replaced by adhesions, necrotic and fibrotic tissue or abscesses. The judgement in the chronic stage is less severe and frequently the removal of affected portions is required without the condemnation of the carcass. However, judgement on the animal or carcass judgement tends to be more complicated in subchronic and sometimes in peracute stages. If generalized necrotic tissue is associated with previous infection, carcass must be condemned. GUIDELINES FOR MINIMUM POSTMORTEM INSPECTION REQUIREMENTS http://www.fao.org/docrep/003/t0756e/T0756E01.htm (4 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries (CATTLE, HORSES, SHEEP & GOATS, PIGS AND GAME) HEADS General View external surfaces. For cattle, horses, pigs and game view the oral and nasal cavities. Lymph nodes (Fig. 1) Submaxillary Incise(a) Parotid Incise(a) Retropharyngeal Incise(a) View and incise by multiple incision or slicing. Fig. 1 : Head inspection. Retropharyngeal (No. 1), parotid (No. 2) and submaxillary (No. 3) lymph nodes are viewed and incised by multiple incisions and slicing. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (5 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 2: Head inspection in buffalo. Retropharyngeal lymph nodes (No. 1) are viewed and incised by multiple incisions and slicing. Tongue View and palpate (view only in calves up to 6 weeks of age). Other Cattle - except in calves up to six week of age, the oesophagus of all cattle and calves should be http://www.fao.org/docrep/003/t0756e/T0756E01.htm (6 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries separated from its attachment to the trachea and viewed. - as part of inspection of all cattle and calves over the age of 6 weeks for Cysticercus bovis, the muscles of mastication should be viewed and one or more linear incisions made parallel to the lower jaw into the external and internal muscles of mastication; in addition one incision into M.triceps brachii, 5 cm behind the elbow, should be made. Horse - the head should be split lengthwise in the medial line and the nasal septum removed and examined in all horses that are from areas where glanders is endemic. Pigs - where there is a risk of Cysticercus cellulosae being present, the outer muscles of mastication, the abdominal and diaphragmatic muscles and the root of the tongue of all pigs should be incised and the blade of the tongue viewed and palpated; Game - inspection cuts for tapeworm cysts are not necessary, as these cysts are generally not infective for humans. NOTES These are guidelines for inspection requirements, the inspection can be made more intensive or less intensive depending on the outcome of the examination. “incise” means multiple incisions or slicing. “palpate” as used above means to view and palpate. GUIDELINES FOR MINIMUM POSTMORTEM INSPECTION REQUIREMENTS (CATTLE, HORSES, SHEEP & GOATS, PIGS AND GAME) VISCERA Lungs (Fig. 3) View and palpate. Except in sheep and goats, the bronchi should be opened up by a transverse incision across the diaphragmatic lobes. For horses and cattle, the larynx, trachea and main bronchi should be opened along their length. Lymph nodes Bronchial (tracheobronchial) and mediastinal: Incise, (a) (see “Notes”) http://www.fao.org/docrep/003/t0756e/T0756E01.htm (7 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 3: Lung inspection - Bronchial left (No. 1) and right (No. 2) and mediastinal (No. 3) lymph nodes are viewed and incised. Fig. 4: Lung inspection in buffalo - Open trachea and incised bronchial and mediastinal lymph nodes. Heart (Fig. 5) http://www.fao.org/docrep/003/t0756e/T0756E01.htm (8 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries View after the removal of the pericardium. Additional inspection requirements for cattle as per (b). Additional inspection requirements for pigs as per (c). Fig. 5: Heart inspection - Lengthwise incisions (minimum four) from base to apex into the heart muscles. Observe cut surfaces. Liver (Fig. 6) View and palpate entire surface(both sides). View the gall bladder. For cattle over 6 weeks of age, incise as deemed appropriate to detect liver flukes. Open large bile ducts. For sheep, pigs and game, incise as deemed appropriate for parasite. Lymph nodes Portal (hepatic), view and incise http://www.fao.org/docrep/003/t0756e/T0756E01.htm (9 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 6: Liver inspection - Incised portal (hepatic) lymph nodes (No. 1) and opened large bile duct (No. 2). Spleen (Fig. 7) Palpate http://www.fao.org/docrep/003/t0756e/T0756E01.htm (10 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 7: Stomachs and spleen inspection - Viewing of rumen and viewing and palpation of spleen. Gastrointestinal tract (Fig. 8) View (a) Mesenteric lymph nodes (Fig. 9), View (a,d) http://www.fao.org/docrep/003/t0756e/T0756E01.htm (11 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 8: Viewing of rumen, reticulum, omasum and abomasum. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (12 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 9: Viewing and incision of the mesenteric lymph nodes. In this case an incision was performed to demonstrate the mesenteric lymph nodes chain. Kidneys View after enucleation. In grey and white horses - Incise. Uterus (adults), View NOTES These are guidelines for inspection requirements, the inspection can be made more intensive or less intensive depending on the outcome of the examination. “incise” means multiple incisions or slicing. “palpate” as used above means to view and palpate. (a) view only in calves up to 6 weeks of age. (b) the heart of all cattle and calves over the age of 6 weeks should be inspected for Cysticercus bovis either by making one or more incisions from base to apex or by everting the heart and making http://www.fao.org/docrep/003/t0756e/T0756E01.htm (13 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries shallow incisions that enable the cardiac valves and muscle tissue to be inspected; this inspection of the heart should also be undertaken in calves up to 6 weeks of age that are from areas where Cysticercus bovis is endemic. (c) the heart of all pigs derived from areas where there is a risk of Cysticercus cellulosae being present, should be opened up and the deep incision made into the septum. (d) incise if any lesion were observed in the submaxillary lymph nodes. GUIDELINES FOR MINIMUM POSTMORTEM INSPECTION REQUIREMENTS (CATTLE, HORSES, SHEEP & GOATS, PIGS AND GAME) CARCASS General Examine carcasses (including musculature, exposed bones, joints, tendon sheaths etc.) to determine any signs of disease or defect. Attention should be paid to bodily condition, efficiency of bleeding, colour, condition of serous membranes (pleura and peritoneum), cleanliness and presence of any unusual odours. Lymph nodes1 Superficial inguinal (male) (Fig. 10) - Palpate Supramammary (female) - Palpate (a) External and internal iliac (Fig. 10, Fig. 11) - Palpate (b) Prepectoral (Fig. 12) - Palpate Popliteal (Fig. 13) - Palpate (only sheep/ goats and game/antelope) Renal (Fig. 12) - Palpate (cattle, horses, pigs) or incise if diseases is suspected. Prescapular (Fig. 14) & prefemoral - Palpate (only sheep and goats) 1 In all animals in which systemic or generalized disease is suspected, in all animals positive to a diagnostic test for tuberculosis, in all animals in which lesions suggestive of tuberculosis are found at postmortem inspection, the main carcass lymph nodes being the precrural, popliteal, anal, superficial inguinal, ischiatic, internal and external iliac, lumber, renal, sternal, prepectoral, prescapular and atlantal nodes, as well as the lymph nodes of the head and viscera, should be incised and examined. Other The muscles and the lymph nodes (lymphonodi sub-rhomboidei) beneath one of the two scapular cartilages of all grey or white horses should be examined for melanosis after loosening the attachment of one shoulder. NOTES These are guidelines for inspection requirements, the inspection can be made more intensive or less intensive depending on the outcome of the examination. “incise” means multiple incisions or slicing. “palpate” as used above means to view and palpate. (a) incise when udder is or has been in lactation or in case of mastitis. (b) means iliac nodes in pigs. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (14 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E01.htm (15 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 10: Superficial inguinal and internal and external iliac lymph nodes in a pig. Viewed and palpated on routine P/M examination. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (16 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 11: Medial view of the hind quarter. Superficial inguinal, internal and external iliac and lumbar lymph nodes are palpated and incised in systemic or generalized disease. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (17 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 12: Medial view of the fore quarter with intercostal, suprasternal, presternal and prepectoral lymph nodes. Presternal and prepectoral lymph nodes are incised. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (18 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 13: Popliteal lymph nodes in a pig. These nodes are incised if a systemic or general disease is suspected. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (19 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 14: Lateral view of the carcass. Precrural and prescapular lymph nodes are incised in systemic or generalized disease. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (20 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E01.htm (21 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 15: Medial view of carcass with relevant lymph nodes ANTEMORTEM AND POSTMORTEM INSPECTION OF POULTRY Antemortem inspection of birds presents some difficulties if the birds are placed in crates or liners, and hence only a superficial inspection of their general condition is carried out. The remainder of the poultry examination should take place after the birds have been hung in shackles and before they are bled. The records of antemortem inspection are mandatory and should include date and time of inspection, truck number, species, the total number of birds and the name of the owner. The objectives of antemortem examination are: to determine the general condition of the birds to establish if a disease or condition requires particular handling such as segregation of diseased birds, delayed slaughter or adjustment of line speed. In inclement weather, particular in winter, birds require immediate slaughter. In the summer, the steady change of air in the truck or in the holding area should be maintained. In cases of reportable disease, such as avian influenza or Newcastle disease, a veterinarian should be informed and all pertinent information should be recorded. Some diseases have similar signs on A/M inspection. For example, infectious bronchitis may be confused with Newcastle disease. A differential diagnosis is required in such cases. Postmortem inspection in poultry refers to inspection techniques and inspection of carcasses and viscera. P/M examination consist of viewing, palpation and smell. The colour, shape, and consistency of organs and tissues must be observed singly or in combination. The colour of the poultry carcass depends on age, sex, nutrition and the scalding temperature during slaughter. Carcasses must be suspended at 2 or 3 points depending on the class of poultry. Intestinal tract, liver, spleen, and heart (viscera) must be exposed for visual examination and palpation. A poultry inspector (Fig. 16) should be able to look inside the carcass and detect any pathological lesions such as airsac inflammation, peritonitis, oviduct inflammation (salpingitis) etc. Contamination by faeces and bile should also be observed. During the examination of viscera and carcass, both hands should be used. External lesions on the carcass include the swelling of the sinuses, nasal and ocular discharge (if the head is present), skin lesions, joint swellings etc. Judgement : Localized lesions could be disposed by an inspector, however the final judgement of the carcass should be done by a veterinarian. The condemnation of carcass is usually for pathological, non pathological and aesthetic reasons. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (22 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig. 16: Inspection of the viscera and carcass in a broiler. SLAUGHTER AND INSPECTION OF GAME ANIMALS FOR MEAT Some parts of the world continue to be blessed with large, thriving populations of game animals, in Africa particularly antelopes such as impala, kudu and eland, in the Southern part of Latin America hares and some deer and antelope species and in Eastern Europe red and roe deer. Controlled cropping of these herds can provide a significant, sustainable source of supplementary protein especially in rural areas. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (23 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries In ideal circumstances and in case of the game meat is for export, two basic systems of culling and carcass preparation can be used. 1. The first system is one of night shooting on foot using spotlights. Animals which appear healthy are shot, immediately bled and the stomachs and intestine eviscerated on the spot. After a number of carcasses have been collected on an accompanying vehicle, they are then transferred to a central, permanent abattoir facility suitable for their dressing, inspection and refrigeration. Since antemortem inspection is performed by hunters, they should be trained in basic antemortem procedures in order that they may be able to select healthy from sick animals. 2. In the second system animals are rounded up and herded into a temporary, funnel like structure. The animals are rested and antemortem inspection is carried out much more objectively. Animals are then shot at point blank range, bled and eviscerated immediately and removed to a temporary butchery for dressing, inspection and refrigeration. Ante and postmortem inspection can be objectively carried out with this system, although hygiene could be somewhat compromised. A judicious combination of features form both these systems, which can be modified, can be used to suit a variety of circumstances in the field. Antemortem and postmortem inspection procedures The inspection procedures that are most appropriate to any particular type of game animal or carcass will vary not only according to species, but also according to whatever other information may be available about the wildlife population from which they are harvested. Minimum inspection procedures as set out in the Joint FAO/WHO Codex Alimentarius Commission's Code of Hygienic Practice for Game, are useful commencing points in developing appropriate procedures. Judgement categories The decision at inspection is classed into the following categories of Judgement: 1. Approved as fit for human consumption. When the inspection and any other information available has revealed no evidence of any unacceptable disease or defect, and if the dressing has been implemented in accordance with hygienic requirements, the game carcass and offal should be approved as fit for human consumption without restriction provided no animal health restrictions are otherwise applicable. 2. Totally unfit for human consumption. The game animal and all offal should be condemned or otherwise disposed of for inedible purposes if: a. they are hazardous for food handlers, consumers and other animals; b. they show decomposition, extensive injury, swelling edema, emaciation or contamination; c. they show signs consistent with natural death, death by trapping or a moribund state. d. there are unacceptable deviations, form normal game meat, detectable by sensory means. 3. Partially condemned. Where lesions are localized, affecting only part of the carcass or offal, the affected parts should be http://www.fao.org/docrep/003/t0756e/T0756E01.htm (24 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries removed and the unaffected parts conditionally or unconditionally passed. Conditions affecting antelope The antelope is perhaps the most preferred and frequently hunted species of game animal in Africa for the specific purpose of providing meat for human consumption. The impala is the easiest of the antelope to cull on a large scale, although the eland is almost as easy to manage as some domestic cattle. Favourable features of antelope are their apparent good herd-health and lack of pathological and parasitic conditions found at meat inspection. Causes of condemnation of the carcass, meat and offal in impala in Africa seem to fall into two categories: a. Management related b. Disease related Management related: trauma - due to gunshot wounds. contamination - chiefly gross dirt attained from the environment during bleeding and de-gutting or intestinal contents during careless evisceration. spoilage and putrefaction - wastage for these reasons can be considerable in Africa if operations are carried out during summer daytime. These losses can be minimized if hunting and dressing are done during the winter months, at night and during lower ambient temperatures. Disease related: Parasites “measles” - tapeworm cysts of various kinds have been found in game carcass such as impala, kudu, bushbuck, reedbuck, sable, wildebeest (gnu, antelope) and warthogs. The cysts vary in size from that of a pea to a golf ball and are often seen in the peritoneal cavity, loosely attached to the serosa, viscera or in the musculature. There are no special predilection sites of the muscular cysts. Routine inspection incisions for measles in domestic animals are of no value in determining presence or degree of infestation in game animals. Serosal affection can be successfully trimmed before release but muscular parasites make the carcass aesthetically unacceptable. In the latter carcass can be boiled or used for manufacturing purposes. These cysts do not seem to affect humans. Sarcocysts - these are frequently seen in the skeletal muscle of impala (mostly microscopic however); the carcass may have to be condemned if severely affected. Stilesia - this tapeworm may be found in the liver of small antelope and seem to be widespread in Africa. Trimming is required. Cooperoides hepatica - this is a small brown filarial worm which occurs coiled up in a cyst in the liver, most frequently in impala. It is often associated with stilesia. Trimming is required. Cordophillus - a filarial worm found encysted in the heart muscle of kudu. 25% of these animals are http://www.fao.org/docrep/003/t0756e/T0756E01.htm (25 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries affected. This parasite is occasionally found in other muscle and may also occur in the heart muscle of domestic cattle. Affected tissue should be trimmed. Hydatid - these cysts have been seen in the lungs and livers of impala, zebra, giraffe and warthog. If slight infestation is present affected tissue should be trimmed. Pathological conditions - the incidence of septicemic/bacteremic conditions and pneumonia were extremely low. SLAUGHTER AND INSPECTION OF FARMED GAME Red deer and fallow deer and some of the antelopes mentioned above are the main species which are farmed for meat production. In particular in New Zealand, but also in Europe and some other regions game farming has become an important source of supplying the domestic and export markets with venison. Farmed game is in many cases slaughtered in special premises and is therefore subject to antemortem and postmortem inspection. Game farmers are now experienced enough to arrange for live animal transports on trucks to the game slaughterhouses. These abattoirs have specific lairages, where the animals can be rested. Slaughter takes place by using captive bolt pistols for stunning and bleeding, deboning evisceration and carcass dressing is similar to cattle slaughter, however carcass splitting is usually not performed. Antemortem and postmortem inspection procedures and conditions affecting the farmed game are similar to the situation described for wild game. However, residues in meat (veterinary drugs, pesticides), parasitic diseases or infectious diseases such as tuberculosis may pose major problems than it is the case in wild game. SLAUGHTER AND INSPECTION OF OSTRICHES The slaughter of farm ostriches is fast becoming a commercial enterprise and may provide an important source of lean, high-protein meat for human consumption. The slaughter and dressing procedures consist essentially of stunning, bleeding defeathering and dressing. These operations are carried out in separate rooms. a. - Stunning. The bird is stunned electrically using 90 volts at 1.5 amperes for approximately 20 seconds. Bleeding. The neck and vessels are severed behind the jaw. De-feathering. This is done manually in order to avoid damage to the skin follicles. b. - Dressing is done in a manner similar to that of small ruminants. Organs are eviscerated in one set. Antemortem inspection : The following are characteristics of apparently healthy ostriches: 1. Alert and inquisitive with a bright eye and erected neck; occasionally lowering and then raising head. 2. Walks with a springy gait and may sometimes be aggressive. 3. Pecks inquisitively at shiny objects. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (26 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries 4. Produces thick, white clear urine and firm faeces. 5. The feathers are fluffed up and the body appears well rounded. The tail is well perked. The following are characteristics of sick ostriches: 1. Lethargic and drooping neck and wings. It may sit down frequently or become recumbent. This clinical sign may also be observed in the stressed bird. 2. The eyes are half closed 3. The mucosa of the mouth may be very congested; the ostriches peck at food but do not swallow. 4. The abdomen may sometimes be bloated and blue/purple. 5. The urine may be green or brown and the faeces fluid or pasty. 6. The feathers appear bedraggled; the wings and tail drop. Postmortem inspection: It will be necessary for the head, pluck (heart, pericardium, liver, spleen, and lung if possible), alimentary tract, genitalia and carcass (with neck and kidney) to be properly identified and presented separately for inspection. The ostrich, like other avian species is lacking an organized lymphatic system. Since many viral and bacterial infections tend to be of a generalized nature, sound and professional meat inspection examination and judgement of the birds and carcass is of great importance. Lungs not removed during dressing procedures should be examined visually and by palpation in the thorax. To expose the lungs, two cuts above the lungs on the each side of the ribs should be made. Head Visual examination of the mouth, palate, eyes, lips and sinuses for icterus, sinusitis, crusting of eyelids and thrush (oral Candida infection) Pluck Lungs - visual and palpation for haemorrhage, edema and pneumonia. Heart - visual and palpation for haemorrhages; expose valves for endocarditis. Pericardium - visual, and incision if necessary; for pericarditis. Liver - visual and palpation; incise if necessary; for icterus, discolouration, adhesions, degeneration, abscess, fibrosis, inflammation and toxic conditions Spleen - visual and incision if necessary; for enlargement, haemorrhages and signs of febrile or septic conditions. Kidney - visual and palpation; for haemorrhages, degeneration, urate crystals. Intestinal tract Oesophagus/proventriculus, gizzard - visual and palpation; for foreign body penetration, impaction, inflammation and ulceration and parasitic conditions (nematode-Libyostrongylus) in glands of proventriculus. Small intestine - visual and palpation; impaction, volvulus, necrotic and catarrhal enteritis and small http://www.fao.org/docrep/003/t0756e/T0756E01.htm (27 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries tapeworm (Houttynia). Large intestine - visual and palpation for faecal impaction, stones, inflammation and nematode (Condiostomum). Reproductive organs - visual for egg retention, rupture, prolapsed penis; Atrophic organs are found during non-breeding season. Carcass Visual inspection of external and internal carcass surfaces, limbs and joints. Observe for contamination, inadequate bleeding, bruising, haemorrhages, lacerations, fracture, dislocation, twisted legs, adhesions, icterus, arthritis, peritonitis, air sacculitis, abscesses (injection sites), foreign bodies. Judgement Carcass should be condemned if affected with any of the following: death from any cause other than slaughter, extensive bruising and haemorrhages, general contamination, putrefaction, emaciation, edema, icterus, septicemia, aspergillosis, toxoplasmosis, malignant or multiple tumours, leucosis, poisoning. The parts of the carcass which show localized lesions may be trimmed and the rest of the carcass would then be approved. SUPERVISION OF HYGIENIC DRESSING OF CARCASSES 1. During dressing the carcass is exposed to contamination from: a. Abattoir environment including implements used, and the hands of the operators. A variety of bacteria, fungi and yeasts are in the abattoir environment. Studies in abattoirs indicate that salmonella counts in the implements used may vary from 0 – 270 per cm2 or more in each implement, depending on their regular cleaning and sanitation the scabbards having the highest numbers. b. Hides of the animals Hides are heavily contaminated parts and can reach up to 3 × 106 bacteria per cm2 or more. c. Stomach and gastrointestinal contents Gastrointestinal contents have the heaviest load of microorganisms. Faeces contain up to 9.0 × 107 bacteria per gram, and various numbers of yeast and mould. The ruminal contents have only slightly lower numbers of micro-organisms. 2. Therefore, during meat inspection it is an important duty of the inspecting officer to ensure that: a. the implements used during slaughtering, dressing and meat inspection are well sanitised periodically or whenever they are likely to be contaminated; b. during cutting into the hide and exposure of the carcass, the external surface of the hide does not contact the carcass meat; c. the viscera are not accidentally opened during the dressing procedures or during evisceration. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (28 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries 3. If a carcass or part is contaminated with faeces or visceral contents such areas should be trimmed off. The opened viscera would have to be separated from the rest of the carcass as quickly as possible. 4. The introduction of a Hazard Analysis Critical Control Point (HACCP) concept can be helpful to maintain high standards of slaughter and dressing hygiene based on an assessment of the risks to human and animal health. HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP) CONCEPT IN MEAT INSPECTION A specific HACCP concept tailored to each abattoir and the class of animal should be developed to ensure the most efficient and effective concept of sanitary control. The introduction of specific HACCP concept involves the following: a. identifying hygienic hazards b. ranking these hazards c. defining the critical limit d. identifying the critical control points e. recommending necessary control f. record keeping g. verification procedures to ensure efficiency h. tests to ensure that the concept is working The Hazard Analysis Critical Control Point (HACCP) Concept was introduced in the food industry in 1971 to ensure that there would be effective control of the quality of processed foods. The World Health Organization (WHO) recommends that this concept also be applied to Meat Inspection and Meat Hygiene in particular to control salmonellosis. It can also be used to reduce bacterial contamination during slaughtering and dressing and to ensure quality control in Meat Inspection. Meat Inspection and Meat Hygiene shall make sure that meat and meat products are safe and wholesome for human consumption. The practise of meat inspection has gradually changed over the last three decades. The classical antemortem and postmortem procedures were designed to detect disease in an animal before slaughter and the lesions produced by the disease after slaughter respectively. This was done by the use of senses (organoleptic tests) such as the use of touch (palpation), sight (inspection and observation), smell (gangrenous smell) and taste (only in cooked products). Zoonotic diseases, particularly tuberculosis received high priority. Laboratory tests were done to confirm the disease when necessary or as appropriate. With the gradual reduction in the incidence of animal tuberculosis in many countries along with the development of intensive methods of animal husbandry and the widespread use of pesticides and veterinary drugs, new problems are emerging. These are associated with residues on one hand and increased human infections with zoonotic agents contaminating animal foods on the other. There appears to be a general trend worldwide, with a few exceptions where human Salmonella infections have nearly doubled during the last five year period and human Campylobacter infections have nearly tripled during the same period. Other bacteria that are causing increasing concern as food contaminants are Yersinia spp. and Listeria spp. There is simultaneously a greater consumer expectation of a longer shelf life in the finished fresh http://www.fao.org/docrep/003/t0756e/T0756E01.htm (29 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries meat product. All these factors suggest that in the practise of meat inspection, it would be advantageous to use the HACCP concept to identify the critical control points at which these bacterial groups and other spoilage organisms may contaminate the carcasses, so that appropriate action can be taken. The critical control points that have been identified for Salmonella contamination in red meats, and poultry are shown in Fig. 17 and Fig. 18. These are applicable to other major bacterial contaminants as well. These figures show that during red meat production, major contamination occurs in the abattoir during skinning and evisceration, that some contamination could occur during transport, lairage and deboning and that the most effective control point is in the chiller. Therefore, it is absolutely essential for meat inspectors to ensure that skinning and evisceration are done properly. The critical control points during the slaughter of poultry (Fig. 18) are picking and evisceration. In developing countries where these tasks are not automated, it is necessary to ensure that proper hygienic precautions are taken during each of these operations. In automated plants, the machinery for picking and evisceration would need to be sanitised regularly, in particular when birds from different sources are slaughtered. Fig. 17: Flow diagram showing sources of contamination with Salmonella and Critical Control Points (CCP) in Red Meat Production. http://www.fao.org/docrep/003/t0756e/T0756E01.htm (30 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries Fig.18: Flow digram showing sources of contamination with Salmonella and CCP in processing of Poultry Meat. (Adapted from WHO 1986) http://www.fao.org/docrep/003/t0756e/T0756E01.htm (31 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E01.htm (32 of 32)10/17/2005 8:02:09 PM Manual on meat inspection for developing countries CHAPTER 2 GENERAL PATHOLOGICAL CONDITIONS Fever (Pyrexia) Fever is an abnormal elevated body temperature. It may be classified as septic and aseptic according to the presence or non presence of an infection. In septic fever the infection is caused by viruses, bacteria, bacterial toxins, protozoa and fungi. Aseptic fever may be caused by a) tissue necrosis as seen in muscle degradation due to intermuscular injection of necrotizing substances, in rapidly growing tumours undergoing necrosis or lysis of burned tissue; b) by chemicals or surgery. In former by an administration of drugs and in latter by breakdown of tissue and blood. c) during anaphylactic reaction of antibodies to the foreign antigens. Antemortem findings : 1. Chills and sweating 2. Dehydration 3. Elevated body temperature 4. Increased pulse and respiration 5. Depression and dullness 6. Anorexia and obstipation In septic fever the other signs may include 7. Diarrhoea and vomiting 8. Urinous or phenolic odour or breath 9. Shock, convulsions and coma Postmortem findings : 1. Rigor mortis 2. Putrefaction 3. Congestion of subcutaneous blood vessels and carcass 4. Enlarged lymph nodes 5. Evidence of cloudy swelling of liver, heart and kidneys Judgement : Carcass is condemned if fever syndrome is associated with presence of bacteria or bacterial toxins in the blood and/or findings of drugs and antimicrobial substances. If typical signs of fevered carcass are not seen carcass should be held for 24 hours after slaughter and re- examined. In case of mild fevered syndrome detected first on postmortem inspection, the carcass may be http://www.fao.org/docrep/003/t0756e/T0756E02.htm (1 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries conditionally approved with heat treatment providing that bacteriological and chemical test are negative. Differential diagnosis : Hyperthermia and septicemia. In hyperthermia the elevation of body temperature is caused by physical factors such as high environmental temperature or prolonged muscular exertion, particularly in humid weather. Inflammation in viral diseases Inflammation associated with viral diseases is usually secondary to primary cellular change. Secondary bacterial infections frequently accompany and complicate viral diseases particularly respiratory and skin diseases. Viral infection associated with fever, malaise, anorexia or incoordination is attributed to absorption of injured cell products, viral toxicity and viral abnormalities which cause circulatory disturbances. Vascular shock together with viral toxicity and failure of one or more vital organs, is thought to be associated with death in viral diseases. Septicemia Septicemia is a morbid condition caused by the presence of pathogenic bacteria and their associated toxins in the blood. The positive diagnosis of septicemia can only be made by isolation of the causative organism from the blood stream. This is not practised on routine antemortem examination of animals in abattoirs; however, the evidence of septicemia is determined by the antemortem and postmortem findings. Antemortem findings : 1. Depression 2. Changes in body temperature. The temperature is usually elevated but it can also be normal and subnormal during the terminal phases. 3. Difficult and rapid breathing 4. Shivering and muscle tremors 5. Congestion or petechial haemorrhages of conjunctivae, mouth and vulvar mucosae Postmortem findings : 1. Enlarged edematous or haemorrhagic lymph nodes 2. Degenerative changes in parenchymatous organs (liver, heart and kidneys) 3. Congestion and petechial or ecchymotic haemorrhages in kidney, heart surface, mucous and serous membranes, connective tissue and panniculus adiposis 4. Splenomegaly 5. Inadequately bled-out carcass as a result of high fever 6. Blood stained serous exudate in abdominal and/or thoracic cavities. 7. Anaemia resulting from bone marrow depression and icterus may also be present. One or more lesions may be absent. However if one significant lesion is present, such as, generalized acute lymphadenitis, the carcass must be condemned. All gross lesions in the carcass and organs must be considered before the animal is judged septicemic. Septicemia is found in many infectious diseases including acute forms of salmonellosis, leptospirosis, swine erysipelas, hog cholera and in anthrax in cattle. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (2 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Judgement : The animals, animal carcasses, offal and other detached portions of animals affected with septicemia are condemned. In borderline cases bacteriological examination should be done wherever possible. Toxaemia The identification of toxaemia presents some difficulties on routine antemortem and postmortem examination. The gross lesions differ depending on the specific organisms and toxins involved. Also the clinical signs of toxaemia simulate a variety of other pathologic conditions. Toxaemia is defined as the presence and rapid proliferation of exotoxin and endotoxin derived from microorganisms or produced by body cells in the blood-stream. Clinical signs and postmortem findings are similar to those of septicemia. Antemortem findings : 1. Normal or subnormal temperature. Fever may be present if toxaemia is due to microorganisms. 2. Confusion and convulsions 3. Abnormal changes in locomotion; 4. Moribund animal or evidence of pain (noted by grinding its teeth). 5. Animal is not able to rise or rises with great difficulty 6. Dehydration may also be present Postmortem findings : 1. Haemorrhage in organs 2. Normal or enlarged and edematous lymph nodes (not hyperplastic as in septicemia) 3. Areas of tissue necrosis 4. Emphysema in cattle 5. Rarely degenerative changes of parenchymatous organs (heart, liver and kidneys). Toxaemia is frequently associated with: 6. Gangrenous mastitis 7. Metritis 8. Aspiration pneumonia 9. Old wounds and injuries 10. Diffuse peritonitis due to perforation of the reticulum or uterus. All these signs may not be seen in every animal affected with toxaemia. Judgement : If there is evidence of septicemia or toxaemia the carcass and the viscera should be condemned and the implements used during inspection and the hands and arms of the inspector should be washed and disinfected. The primary lesions causing septicemia or toxaemia including metritis, mastitis, pericarditis, enteritis and others, should be observed and recorded as causes of condemnation. Comatose or moribund animals should be condemned on antemortem examination. Pigmentation http://www.fao.org/docrep/003/t0756e/T0756E02.htm (3 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Pigments are classified as exogenous and endogenous. Exogenous pigments are synthesized outside of the body and endogenous within the body itself. Pigments are coloured substances which accumulate in the body cells during the normal physiological process and abnormally in certain tumours and conditions. They have a different origins, biological significance, and chemical composition. In anthracosis, the carbon particles are found as a black pigment in tissues. This condition is seen as black pigment of the lungs and corresponding lymph nodes in animals raised in urban areas. The lungs affected with anthracosis are condemned and the carcass is approved. The carotenoid pigments are exogenous pigments, greenish-yellow in colour which consist of carotene A, carotene B, and xanthophyll. They are important in meat inspection because they cause yellowish discoloration in the fat and muscles of (Jersey and Guernsey) cattle. Carotenoid pigments should be differentiated from bile pigments in icterus. The bovine liver affected with this condition is enlarged and shows a bright yellow colour. Such a liver is condemned with the rationale that the affected liver demonstrates some toxic changes, as damaged liver cells cannot metabolize carotene. Liver carotenosis must be differentiated from pale livers in advanced pregnancy. The endogenous pigments, except for melanin and lipofuscin are derivates of haemoglobin. (A) Melanosis Melanosis is an accumulation of melanin in various organs including the kidneys, heart, lungs and liver (Fig. 19), and other locations such as brain membranes, spinal cord, connective tissue, periosteum etc. Melanin is an endogenous brown-black pigment randomly distributed in tissue. In grey and white horses, this pigment is found under the shoulder, axillary area and ligamentum nuchae. Melanin is also found in lymph nodes, pig skin and belly fat or mammary tissue in female pigs. This condition is called “seedy belly” or “seedy cut” since the black colour in the mammary tissue resembles round, black seeds. The melanotic tissue in pigs shows a tendency towards neoplasia. Melanin deposits in the oesophagus and adrenal glands in older sheep are a common finding on postmortem examination. Multifocal deposits of melanin in the liver of a calf is known as “Melanosis maculosa”. It is common in calves and it usually disappears after the first year of age. Judgement : Carcasses showing extensive melanosis are condemned. If the condition is localized, only the affected organ or part of the carcass needs to be condemned. Differential diagnosis : Haemorrhage, Melanoma, Distomatosis (liver flukes) (B) Myocardial lipofuscinosis (Brown atrophy of the heart, Xanthosis) Xanthosis (“Wear-and-Tear”) pigment is a brown pigmentation of skeletal and heart muscles of cattle (Fig. 20). The condition is seen in old animals such as “cull dairy cows” and in some chronic wasting diseases. It is prevalent in Ayrshire cows and approximately 28 % of normal Ayrshire cows have this pigment in skeletal and heart muscles. Xanthosis is not dependent on the age of animals in this breed. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (4 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E02.htm (5 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 19: Melanin deposits in the sheep viscera. Fig. 20: Myocardial lipofuscinosis. (C) Congenital porphyria (osteohemochromatosis, pink tooth) Porphyria is the accumulation of plant or endogenous porphyrins in the blood resulting in tissue pigmentation and photosensitization. This is a hereditary disease and is observed in cattle, swine and sheep. In porphyric cattle, exposure to light will initiate the development of photodynamic dermatitis. In swine, photodynamic dermatitis does not occur. The disease is also known as osteohemochromatosis, due to a reddish brown bone pigmentation (Fig. 21), and “pink tooth” because of a brownish-pink discoloration of teeth. Judgement : Carcass showing extensive xanthosis is condemned. If the condition is localized, only the affected organ or part of the carcass needs to be condemned. Head and bones of a carcass affected with osteohemochromatosis are condemned. The bones are “boned out” and remaining muscles are approved. If the condition is generalized the carcass is condemned. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (6 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 21 : Osteohemo- chromatosis showing brown pigmentation of ribs and vertebrae in a 6 months old calf. (D) Icterus(Jaundice) Icterus is the result of an abnormal accumulation of bile pigment, bilirubin, or of haemoglobin in the blood. Yellow pigmentation is observed in the skin, internal organs (Fig. 22, 23), sclerae (the white of the eye), tendons, cartilage, arteries, joint surfaces etc. Icterus is a clinical sign of a faulty liver or bile duct malfunction, but it may be also caused by diseases in which the liver is not impaired. Jaundice is divided into three main categories (Fig. 24). 1. Prehepatic jaundice (haemolytic icterus) 2. Hepatic jaundice (toxic icterus) 3. Posthepatic jaundice (obstructive icterus) http://www.fao.org/docrep/003/t0756e/T0756E02.htm (7 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 22: Jaundice of an aged cow caused by liver disease. Note yellow discoloration of body fat, lungs, heart and kidneys. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (8 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E02.htm (9 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 23: Yellow discoloration of pig viscera and carcass caused by cirrhosis of the liver. Fig. 24: Classification of jaundice 1. Pre-hepatic: 2. Hepatic: 3. Post-hepatic Prehepatic jaundice occurs following excessive destruction of red blood cells. Tick-borne diseases such as Babesia ovis and Anaplasmosis cause this type of icterus, which is one of the main causes of carcass condemnation in Southern Africa due to prevalence of these parasites. Overproduced blood pigment, which cannot be metabolized in the liver, builds up in the blood (haemoglobinemia). It is excreted by the kidneys into the urine (haemoglobinuria). Normal urine colour changes and becomes bright red to dark red. Hepatic jaundice occurs due to direct damage to liver cells as seen in liver cirrhosis (Fig. 23), systemic infections, and in chemical and plant poisoning. In sheep, jaundice may have been caused by phytogenic chronic copper poisoning. Liver function is impaired and the liver is unable to secrete bile pigments. Obstructive jaundice occurs when the drainage of the bile pigment bilirubin is blocked from entry into the intestine. This usually occurs due to the obstruction of the hepatic ducts by a tumour, by parasites such as flukes or by gall stones. Obstruction may also occur due to an inflammation of the bile ducts. In hogs, mature ascarides may occlude the bile ducts. Judgement : Animals suspected to have icterus should be treated as “suspects” on antemortem examination. On postmortem examination, the carcass and viscera with haemolytic, toxic icterus and http://www.fao.org/docrep/003/t0756e/T0756E02.htm (10 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries obstructive icterus are condemned. Less severe cases are kept in the chiller for 24 hours. Upon re- examination, the carcass may be approved or condemned depending on the absence or presence of pigment in the tissue. If the obstructive icterus disappears after 24 hours, the carcass and viscera can be passed for human food. A simple laboratory test will help to make an objective test for bile pigment icterus. Two drops of serum are mixed on a white tile with two drops of Fouchets agent.2 A blue/green precipitate is positive for bile icterus. 2 Fouchets Reagent Trichloroacetic acid. 25 gm FeCl3 (10 % solution) 10 ml Distilled water 100 ml Differential diagnosis : Yellow fat in animals with heavy corn rations, nutritional panniculitis (yellow fat disease, steatitis) and yellow fat seen in extensive bruises. In yellow fat disease, the fat has a rancid odour and flavour upon cooking. To differentiate icterus from the normal colour of fat of certain breeds, the sclera, intima of the blood vessels, bone cartilage, liver, connective tissue and renal pelvis should be examined. If yellow discoloration is not noted in these tissues, icterus is not present. Icterus should not be confused with yellow fat disease in hogs fed predominantly on fish by-products or by the yellowish appearance of tissue caused by breed characteristics or nutritional factors. Haemorrhage and Haematoma Haemorrhage is seen at slaughter in various organs, mucous and serous membranes, skin, subcutaneous tissue and muscles. It may be caused by trauma, acute infectious diseases or septicemia. In pigs muscles haemorrhage is frequently associated with fractures (Fig. 25). Petechial haemorrhage is noted as tiny foci 1 – 2 mm in diameter. Ecchymotic haemorrhage (Fig. 26) is larger being up to 2 - 3 cm in size. Paint brush haemorrhage includes extensive streaking with haemorrhage. Haemorrhage is also associated with vitamin C deficiencies, a sudden increase in blood pressure with weakened blood vessels, and improper electric current stunning in pigs and sheep. Lengthy transportation, exposure to stress before slaughter, hot weather and excitement are some of the other factors which contribute to muscle haemorrhage. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (11 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E02.htm (12 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 25: Fractured bone and muscle haemorrhage in a market hog. Fig. 26: Ecchymotic haemorrhage in the tongue muscle of a cow. In haemorrhage caused by improper stunning, there may be a delay between stunning and sticking of the animal. The electrical current used in stunning causes cardiac muscle stimulation and vasoconstriction of blood vessels. This might induce a rapid rise in blood pressure leading to haemorrhages in the organs and muscle (so called “blood splashing”). The stunning of animals by a mechanical blow to the head is still practised with sheep and is a significant cause of haemorrhage in organs particularly the lungs and heart. The blow to the head will initiate a rise in blood pressure. The normal arterial blood pressure in sheep is 120 – 145 mm/Hg. This may rise to 260 mm/Hg or over in a stunned animal. The heart rate will be increased. Immediate bleeding with the fast blood flow from the cut vessels could prevent this type of haemorrhage in sheep. Agonal haemorrhage (due to rupture of capillaries) is caused by laboured breathing and contraction of musculature during violent death. A lump formed from a blood clot in tissues or organs is called a haematoma. Haematoma varies in size and may be over one meter in diameter (Fig. 27). They are associated with trauma or a clotting defect. Haematoma of the spleen (Fig. 28) may be associated by head butting by horned animals. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (13 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Judgement : A carcass is approved if the haemorrhage is minor in extent and is due to physical causes. The affected tissue is condemned. A carcass affected with extensive haemorrhage where salvaging is impractical, or a haemorrhagic carcass associated with septicemia is condemned. Differential diagnosis : Haemorrhage resulting from blackleg, and sweet clover poisoning. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (14 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 27 : Haematoma in the abdominal wall of an ewe. Fig. 28: Haematoma of the bovine spleen. Bruises Bruises are frequently found on antemortem and post-mortem examination in food producing animals and poultry. In cattle bruises caused by transportation or handling are commonly found in the hip, chest and shoulder areas; in pigs within the ham and in sheep in the hind leg. Bruises and haemorrhage in the hip joint are caused by rough handling of animals during shackling. Bruises in poultry can be localized or generalized and are frequently associated with bone fractures or ruptured ligament tendons. Judgement : Bruised animals should be treated as suspects on ante mortem examination. On http://www.fao.org/docrep/003/t0756e/T0756E02.htm (15 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries postmortem examination, carcasses affected with local bruising are approved after being trimmed. Carcasses affected with bruises or injuries associated with inflammatory lesions are also approved if tissue reaction does not extend beyond the regional lymph nodes. The affected area should be condemned. When bruises or injuries are associated with systemic change and the wholesomeness of the musculature is lost, the carcass will be condemned. On postmortem examination of bird carcasses affected with bruises and fractures, the following judgement should be observed: (a) the fractures associated with bruises are removed and affected tissue is condemned, (b) in compound fractures with damaged skin, the fractured site and surrounding tissue are condemned; (c) in simple fractured without bruises and damaged skin, the affected portion may be approved for mechanical and manual boning operations. If the lower part of bone is fractured, the bone may be removed by cutting above the fracture. A carcass affected with extensive bruises is condemned on postmortem examination (Fig. 29). A slightly or moderately bruised carcass is approved if no systemic changes are present. Affected tissues are condemned. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (16 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 29: Extensive bruises of a beef carcass. Abscess An abscess is a localized collection of pus separated from the surrounding tissue by a fibrous capsule. The most common bacteria in liver abscesses include Actinomyces (Corynebacterium) pyogenes, Streptococcus spp. and Staphylococcus spp. In the lungs the most common bacteria are Pasteurella spp. and Actinomyces pyogenes. Fusobacterium (Sphaerophorus) necrophorum causes liver abscesses (Fig. 30) as a complication of rumen inflammation (rumenitis) in adult cattle. This condition is common in feedlots where cattle are fed a high grain diet which produces acidity in the rumen and ulcerative rumenitis. The rumen lesion is invaded by F. necrophorum which pass further via the veins to the liver and stimulate abscess formation. Fig. 30:Liver abscesses caused by Fusobacterium necrophorum. Judgement : The judgement of animals and carcasses affected with abscesses depends on findings of primary or secondary abscesses in the animal. The portal of entry of pyogenic organisms into the system http://www.fao.org/docrep/003/t0756e/T0756E02.htm (17 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries is also of importance. The primary abscess is usually situated in tissue which has contact with the digestive tract, respiratory tract, subcutaneous tissue, liver etc. The secondary abscess is found in tissue where contact with these body systems and organs is via the blood stream. The brain, bone marrow, spinal cord, renal cortex, ovary and spleen (Fig. 31) may be affected with secondary abscesses. In judgement of the carcass, the inflammation of the renal medulla and contact infection in the spleen and ovaries must be ruled out. A single huge abscess found in one of the sites of secondary abscesses may cause the condemnation of a carcass if toxaemia is present. In pigs an abscess is frequently observed in the jaw and in the spine. Spinal abscesses in pigs are commonly caused by tail biting (Fig. 32). The bacterial agent from the tail penetrating the spinal canal could be arrested in the lumbo-sacral and cervical spinal enlargements, initiating an abscess formation. Inspectors should differentiate the abscesses in the active and growing state from the older calcified or healed abscesses. In domestic animals, the primary sites of purulent infections are post-partum uterus, umbilicus or reticulum in “hardware disease”. Secondary abscesses are frequently observed in distant organs. Small multiple abscesses may develop in the liver of calves as a result of infection of the umbilicus (“sawdust liver”, Fig. 33). Carcasses with such condition should be condemned. The animals affected with abscesses spread through the blood stream (pyemia) are condemned on antemortem if the findings of abscesses are over most areas of the body and systemic involvement is evident as shown in elevated temperature and cachexia. On postmortem examination, the carcasses are condemned for abscesses, if the abscesses resulted from entry of pyogenic organisms into the blood stream and into the abdominal organs, spine or musculature. An abscess in the lungs may require condemnation of the lungs and an passing the carcass if no other lesions are noted. Liver abscesses associated with umbilical infection require condemnation of the carcass. If no other infection is present the abscess is trimmed off and the liver may be utilized for human or animal food depending on the regulations of the respective country. Multiple abscesses in the liver require condemnation of the organ. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (18 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 31: Secondary abscesses in the spleen of an aged cow. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (19 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 32: Tail necrosis caused by biting and secondary spine abscesses. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (20 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig.33: Multiple abscesses in the calf liver as a result of an umbilical infection; carcass with such condition should be condemned. Emaciation Emaciation is a common condition of food animals and is characterized by a loss of fat and flesh following the loss of appetite, starvation and cachexia. It is associated with gradual diminution in the size of organs and muscular tissue as well as edema in many cases. The organs and muscular tissue appears thinner, moist and glossy. Cachexia is a clinical term for a chronic debilitating condition or general physical wasting caused by chronic disease. Emaciation may be associated with chronic diseases and parasitic conditions such as round worms in pigs and fascioliasis in cattle and sheep, swine erysipelas, neoplasms, tuberculosis, John's disease, caseous lymphadenitis, and poor teeth and lack of nutrition. Emaciation is a postmortem descriptive term which should be differentiated from thinness. Antemortem findings : 1. Wrinkled, dry leathery skin (Fig. 34) 2. Rough hair coat 3. Prominent bones and sunken eyes Postmortem findings : http://www.fao.org/docrep/003/t0756e/T0756E02.htm (21 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries 1. Serious atrophy of fat in the carcass and organs especially the pericardial and renal fat (Fig. 35). 2. The fat is watery. Tranluscent or jelly-like and hangs from the intervertebral spaces (Fig. 36). 3. Edema and anaemia may develop due to starvation and malnutrition due to parasite infestations. Judgement : Animals affected with emaciation should be treated as “suspects” on antemortem inspection. On postmortem examination it is important to assess and differentiate emaciation from leanness. In case of doubt, the carcass may be held in the refrigerated room and the general setting of the carcass should be examined the following day. If the body cavities are relatively dry, edema of muscle tissue is not present and fat is of an acceptable consistency i.e. has “set”, the carcass may be passed for food. Well nourished carcasses with serous atrophy of the heart and kidneys and mere leanness may also be fit for human consumption. A carcass with any amount of normal fat may be approved if everything else appears normal. The carcasses from animals being in transport for a long period of time may show extensive serous atrophy of fat (mucoid degeneration of fat tissue) without any changes in organs and muscles. If after being in the cooler for 24–48 hours, the fat resumes its normal consistency, the carcass is approved. Otherwise, the carcass is condemned. The carcass and viscera must be condemned if emaciation is due to chronic infectious disease. An objective judgement of emaciation with edema may be made using a 47 % ethanol/methanol in water solution. A clear, pea-sized piece of bone marrow, taken from the distal radius, is put carefully into the solution. If it sinks, the marrow which reflect the water content of the carcass as a whole, has approximately 45 % water content. The carcass should be condemned. Differential diagnosis : Thinness-leanness, edema and uraemia. Leanness (Poorness) is often observed in range bulls on poor quality pasture, high milking cows and young growing animals which have had protein deficient diet. The animals are physiologically normal and the reduced fat deposits of the animal carcass are normal in colour and consistency. The reduced muscle tissue is firm and of a normal consistency. The muscle colour is darker than normal, and fat tissue may still be present in the orbit of the eye. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (22 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries http://www.fao.org/docrep/003/t0756e/T0756E02.htm (23 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 34: Emaciated cow showing marked reduction of muscle mass. Fig. 35: Serous atrophy of renal fat. Note petechial haemorrhages, seen frequently in septicemic diseases. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (24 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Fig. 36: Hanging gelatinous fat between the spinal process. Edema Edema is the accumulation of excess fluid in the intercellular (interstitial) tissue compartments, including body cavities. There are two types of edema: 1. Inflammatory edema (exudate) 2. Non-inflammatory (transudate) Inflammatory edema shows yellow, white or greenish clear or cloudy fluid in the area of inflammation. Non- inflammatory edema is an accumulation of fluid in subcutaneous tissue, submucosae, lungs and brain. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (25 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Localized edema is noted after: a. The swelling of a leg of a cow in prolonged decubitus. This swelling is caused by obstruction of the venous outflow b. Interference with the lymph circulation of an organ or area by proliferation of tumours in or around bile ducts. c. Inflammation or an allergic reaction Systemic or generalized edema may occur secondary to congestive heart failure or is caused by low protein levels in the blood. The latter may be associated with: severe malnutrition severe amyloidosis of the kidney gastrointestinal parasitic infestation chronic liver disease damage to the vascular endothelium by toxins and infectious agents Anasarca is a form of edema of the subcutaneous tissues. Ascites is an accumulation of fluid in the peritoneal cavity. Hydrothorax is an accumulation of fluid in the pleural cavity. Hydrothorax may accompany traumatic pericarditis, ascites, cirrhosis of the liver and round worm infestation in sheep. Anasarca may be caused by toxaemic infection. Antemortem findings : 1. Depressed and drowsy 2. Swelling of the mandible, dewlap, legs, shoulder, brisket and abdomen (Fig. 37) 3. Edematous tissue is cool upon touch and is of a firm, doughy consistency. Postmortem findings : 1. Wet, sloppy musculature which pits on pressure 2. Accumulation of clear or faint yellow fluid in the thorax, abdomen and subcutaneous tissue Judgement: Animals affected with generalized edema may be condemned on antemortem inspection. In less severe non-generalized cases, animals are treated as “suspects”. When making a judgement of a carcass affected with edema, it is important to know the underlying cause of the edema and also to know the significance of all other lesions found in the carcass. The carcass may be totally or partially condemned depending on the extent and cause of the condition. The presence of localized edema necessitates removal of the affected area. The carcass is then approved. Edema associated with diseased conditions such as traumatic pericarditis, malignant neoplasm or septicemia requires condemnation of the carcass because of the primary condition. Edema observed in the mesentery is commonly related to circulation interference in the caudal vena cava due to liver abscess or chronic liver disease. Such a carcass may be held in the cooler for re-examination. Dry serous membranes of the abdominal and thoracic walls and a carcass appearing normal after re-examination can be passed for human consumption. Carcasses which have been condemned for edema associated with malnutrition only may be salvaged for animal food (except in case of edema associated with septicemia). http://www.fao.org/docrep/003/t0756e/T0756E02.htm (26 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Differential diagnosis : Pericarditis, peritonitis, pleuritis, renal amyloidosis, liver disease, grain overload and vagal indigestion, high altitude disease, uraemia and absorption of a large bruised area. Fig.37: Abdominal edema caused by liver disease. Emphysema Emphysema in animals is associated with some disease conditions and is caused by an obstruction to the outflow of a air or by extensive gasping respiration during slaughter procedures. All species may be affected with alveolar emphysema. However interstitial emphysema (Fig. 38) occurs mostly in cattle. In the latter, the lack of collateral ventilation forces the rupture of alveoli and the migration of air into the interstitium. The lobules of the lungs become separated by the distended interstitial tissue and marked lobulation of lungs is observed. Alveolar emphysema appears as small air bubbles due to air trapped in dilated alveoli. Large accumulations of air, a few centimetres in diameter, are called “bullae or bullous emphysema”. Postmortem findings: Postmortem findings of the emphysematous lungs include a pale, enlarged greyish-yellow, pearl like shiny lesion. Upon palpation, the affected area feels puffy and crepitant. Two diseases of food animals associated with emphysema are chronic obstructive pulmonary disease (COPD) in horses, and interstitial pneumonia in cattle. COPD is also called heaves and frequently http://www.fao.org/docrep/003/t0756e/T0756E02.htm (27 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries described under chronic bronchitis or bronchiolitis in horses. Interstitial pneumonia in cattle is also described under fog fever or acute chronic pulmonary edema and emphysema. Judgement: Affected lungs are condemned. Fig. 38: Interstitial emphysema in the cow's lungs. Tumours or neoplasms A tumour is an abnormal mass of tissue which grows without control and uncoordinated with the tissue or organs of origin or those nearby. Its presence if often cumbersome to the tissue or organ it arose either by pressure or by replacement of normal functional tissue. Tumour cells resemble healthy cells however serve no useful purpose. The term tumour in current medical lexicon is presently limited to neoplastic growths. Tumours are usually divided according to tissue of origin i.e. epithelial, mesenchymal (connective tissue), haemopoietic, nervous etc. Tumour behavioral classification include their mode of growth and the degree of invasiveness. Slow growing non invasive circumscribed tumours are considered benign and fast growing, infiltrative and frequently metastatic are malignant tumours. The spread of neoplasm is by direct expansion and infiltration, via lymphatics and blood circulation and by implantation. Carcinoma are tumours of the epithelial tissue. They are usually spread via the lymphatic system. Sarcoma are connective tissue tumours, commonly spread via haematogenous route. Implantation to surrounding parietal cavities is observed in ovarian carcinoma. The spread of malignant tumours via lymphatics or http://www.fao.org/docrep/003/t0756e/T0756E02.htm (28 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries haematogenous spread to another area not directly connected with the original site is called metastasia. Some of the common tumours found during beef inspection are squamous cell carcinoma, lymphosarcoma, pheochromocytoma, mesothelioma etc. Fig. 39: Squamous cell carcinoma affecting cow's eye and parotic lymph node. In this case, tumour lesions were also observed in the lungs. Carcass was condemned. http://www.fao.org/docrep/003/t0756e/T0756E02.htm (29 of 38)10/17/2005 8:02:37 PM Manual on meat inspection for developing countries Judgement: Carcass affected with metastatic neoplasms is condemned. Multiple benign tumours in different organs also require condemnation of carcass. Carcass affected with circumscribed benign tumours is approved. Calcification Calcification is the deposition of calcium salts in dead and degenerating tissue. It may be regarded as a body reaction to immobilize some foreign agents. It may occur in any tissue or organ. In dairy cows, calcification is noted in the heart (endocardium) and is caused by excessive dietary supplementation with Vitamin D. In cattle mineralization of the aorta and brachiocephalic trunk (Fig. 40) is sometimes seen. Calcification is also seen in parasitic infections (Fig. 41) and in many chronic infections such as