Animal Diseases and Their Causes of Disease PDF

Chapter IV ANIMAL DISEASES AND ITS CAUSES OF DISEASE At the end of this chapter, the students should be able to: 1. discuss how disease enters an animal's body and how to counter it 2. be familiar of the causative agents of different diseases; and 3. value biosecu...

Chapter IV ANIMAL DISEASES AND ITS CAUSES OF DISEASE At the end of this chapter, the students should be able to: 1. discuss how disease enters an animal's body and how to counter it 2. be familiar of the causative agents of different diseases; and 3. value biosecurity in disease control and prevention. INTRODUCTION In order to understand what causes disease in animals, we first need to know what disease is. Disease (also known as sickness) is any process that interferes with the way the different parts of the body work and look. We do not normally consider injuries such as broken legs and cuts as diseases. On the other hand, Disease is an alteration of the body or body organs which interrupts or disturbs the body’s function. Such disturbances often are recognized by detectable alterations of body functions. Etiology is the study of disease causes. A disease often results from a combination of two or more causes: (1) the indirect or predisposing factors which may lower the animal’s resistance and (2) the direct or determining factors which produce the actual disease. Predisposing causes of disease are referred to frequently as “stress” factors. Stress factors include chilling, poor ventilation, overcrowding, inadequate feeding and watering space, overmedication, etc. Times to be particularly aware of stress are at shipping and weaning. Direct causes of disease are: (1) bacteria, (2) viruses, (3) parasites, (4) fungi, (5) nutritional deficiencies, (6) chemical poisons, and (7) unknown causes. A. METHODS BY WHICH INFECTIOUS AGENTS GAIN ENTRANCE INTO ANIMAL’S BODY 1. Mouth 2. Upper respiratory system 3. Skin 4. Insect bite 5. Mucous membrane of the eye 6. Coitus (mating) 7. Udder 8. Ruptured navel cord 9. Contaminated needles, syringes, equipments 52 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s B. DEVELOPMENT OF INFECTIOUS AGENTS IN THE BODY 1. May localize at the site of entry e.g. pyometra 2. Multiply by extension and penetrate surrounding tissues e.g. rabies, cancer 3. Can produce septicemia (microorganisms invade and multiply in the bloodstream) e.g. hog cholera and anthrax C. BODY’S DEFENSES AGAINST DISEASE 1. Skin and mucous membrane – these are the first lines of defense againsts infectious agents 2. Sweat and tears – contain helful protein (lysozyme) 3. Lymph – has antiseptic substances and carries leukocytes and macrophages 4. Filter organs – lymph glands, spleen and liver 5. Body’s various reactive defenses a. Inflammatory reaction (inflammation) – reaction of the tissue to an irritant with the following cardinal signs: i. Redness – due to greatly increased blood supply to the damaged or diseased area ii. Swelling – comes from substances leaking from the dilated and stretched vessel walls into surrounding tissues. These substances are called exudates. iii. Heat – results from increased flow of blood through the affected area iv. Pain – attributed to increased tissue pressure upon nerve findings. b. Febrile reaction (fever) – this is the resting of the thermoregulatory mechanism of the body above the normal level due to microorganisms c. Immune reaction (immunity) – the condition of a living organism whereby it resist and overcomes infection or disease. Types of immunity: i. Active immuntiy  comes about the animals tissues actively participating in production of antibodies,  the material being introduced into the animals body are antigen,  it can be acquired by having the diseases and recovering (natural) or by being given injection of biological agent or vaccine (artificial)  duration is usually last for months and years. ii. Passive immunity  conferred to an animal without necessity of its tissues to participate in the production of antibodies  the material being introduced into the animals body are antibodies  it can be acquired by sucking of colostrum and placental transfer (natural) and injection of antiserum (artificial)  duration is usually relatively short (often only a few weeks) 53 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s D. PREDISPOSING FACTORS IN DISEASE PRODUCTION 1. domestication 2. Underfeeding 3. improper management 4. natural factors E. CAUSATIVE AGENTS OF DISEASES 1. Bacteria Bacteria are microscopic, single-celled organisms that thrive in diverse environments. Classification of Bacteria a. Gram – positive or gram – negative Gram positive bacteria strain red. Gram negative bacteria strain dark blue or black. b. Aerobic or anaerobic Aerobic bacteria grow in the presence of atmospheric oxygen. Anaerobic bacteria are capable of producing their own oxygen. c. Spore forming or non-spore forming Spore forming bacteria produce spores that may persist in animal surrounding for years. Non-spore forming bacteria do not produce spores d. Acid-fast and nonacid-fast Acid-fast bacteria stains red and are quite resistant to drying and disinfectants Non-acid fast bacteria do not have stain. Morphology: o Coccus (berry-shaped) - small round bacteria usually gram-positive which arranged in small chains (streptococcus), arranged in clumps or clusters like grapes (staphylococcus) and arranged in pairs (diplococcus). o Bacillus (rod-shaped) - bacteria are arranged as short or long rods singly, paired or in chains. o Spirochetes (corkscrew-shaped) - these bacteria are motile and require moist surroundings for survival. 2. Fungi Fungi are eukaryotic, non-photosynthetic, filamentous or unicellular organism that reproduces asexually or sexually (spores). 54 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 3. Virus Virus are submicroscopic organism that can be grown using living tissue. It has a DNA or RNA protein capsid (covering). Classification of virus: a. DNA viruses: Parvovirus (only known virus with single-stranded DNA), Poxvirus (largest vertebrate virus) and Adenovirus b. RNA viruses: Paramyxovirus Togavirus Coronavirus Reovirus (only double stranded RNA virus) 4. Mycoplasma It is a tiny bacterium which has a size between a virus and bacteria. They do not grow or stain like other bacteria but they will grow on special media if blood serum is added. 5. Rickettsia Are true bacteria but they are non-filterable and are gram negative. They can be cultivated outside the host only in living tissues. They are usually associated with the tissues of some arthropods. 6. Protozoa It is the most primitive member of the animal kingdom. It is single-celled organism and eukaryotic. It has not chlorophyll – containing chromophores that’s why it utilized the performed food material it derived from living organisms. 7. Metazoan Parasites a. Flatworms/tapeworms - hermaphrodite endoparasitic worms with an elongated flat body and without a body cavity or alimentary canal. b. Flukes - endoparasitic worms whose bodies are dorsoventrally flattened, unsegmented and leaflike. c. Roundworms - free living or parasitic endoparasites, unsegmented and usually cylindrical and elongated in shape and with alimentary canal. 8. Anthropods (external parasites) These are referred to as jointed legs parasites. They have hard external skeletons or exoskeleton composed of a substance called chitin. They have a segmented body. In this category belong the mites, ticks, flies, lice, fleas, mosquitos etc. 55 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  PARASITES OF POULTRY AND LIVESTOCK  Parasites - are organisms that live in or on other oganisms known as hosts and at whose expense they (parasites) obtain some advantage without compensation.  Endoparasites - are parasites that live within the host.  Ectoparasites - parasites that live outside the body of the host.  Host are the organism that harbors a parasite. There are two types of host: a. Definitive host – a host harboring the sexual, adult stage of the parasite. b. Intermediate host – a host harboring an asexual or larval stage of the parasite.  Parasitosis - association between two organisms in which one injuries the other causing signs and lesions of disease.  Parasitiasis - association between two organisms in which the parasite is potentially photogenic but does not cause signs of disease.  Commensalism - association in which one partners (the parasite) is benefited and other (the host) is neither benefited nor harmed.  Symbios - association between host and parasite that is necessary for both and from which both benefit.  Mutualism - similar to symbiosis but the relationship between host and parasite is not essential and the host can get along well enough without the parasite.  Vector - arthropod or other invertebrate that transmits the parasite from one vertebrate host to another.  Life cycle - tt refers to the development of the parasite through its various stages.  Infective host - it is that period in the life cycle of parasites in which they are ready to infect their final host.  Larval stage - it is the form most internal parasites reach following their hatching from eggs.  Pupal stage - it is the phase of development in which the life cycle if insect parasites follow after their larval stages. In this stage, the parasite is inactive.  Molting - it is casting of the skin or cuticle when advancing in development. Parasites may injure their host in several ways: 1. They may suck blood, lymph or exudates 2. They may feed on solid tissues 3. They may compete with the host for the food 4. They may cause mechanical obstructions 5. They may cause pressure atrophy 6. They may destroy host cells by growing in them 7. They may produce various toxic substances 8. They may cause allergic reactions 56 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  9. They may stimulated the development of cancer 10. They may carry diseases and parasites 11. They may reduce their hosts resistance to other diseases and parasites ECTOPARASITES Ectoparasites are a taxonomically diverse group of organisms that infest the skin of human beings and other animals. Ectoparasitic arthropods and nematodes are similar in that an individual organism can produce skin lesions that are large enough to see with the unaided eye. A. Flies are often abundant and are found in almost all terrestrial habitats in the world The Life Cycle of flies: Female flies laid eggs in feces, in bodies of water, vegetation or marshy areas. Eggs hatch under optimal temperatures to produce larvae (maggots). The maggots undergo three instar stages and then pupate in the final larval skin. The adult fly emerges after several days or weeks. a. Tabanus spp (horseflies or breeze flies)  they cause annoyance and blood loss to animals. they also transmit anthrax, anaplasmosis and virus of equine infectious anemia. b. Musca domestica (common housefly)  it regurgitates at frequent intervals to aid its feeding (vomit drop) and it defecates at random – these activities are responsible for the mechanical transmission of diseases like enteric diseases, cholera and entamoeba. c. Stomoxys calcitrans (stable flies)  they can mechanically transmit anthrax, anaplasmosis and other blood diseases. d. Culicoides spp (biting midges or punkies)  they cause annoyance to hosts and transmit viral diseases like bluetongue as well as african horse sickness. e. Haematobia irritans (horn flies)  they spend most of their adult life on their hosts, almost exclusively cattle, using the latter both as a source of food and resting place between meals. Control the flies by: 1. drain possible breeding places 2. use of organophosphate/insecticides 3. proper disposal of manure and garbage B. Mosquitoes Mosquitoes sometimes attack livestock in such number that animal death or serious production losses occur. Injuries that mosquitoes inflict on livestock are mostly severe annoyance, blood loss and transmission of several blood diseases. Also, it is likely that 57 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s toxins injected by mosquitoes at the same time of blood sucking may cause severe systemic effects. Life cycle of moquitoes: After a blood meal the gravid female lays up eggs of the surface of water either singly or in the case of Culex in groups forming egg-rafts and in the case of Anopheles boat-shaped. Hatching is temperature dependent occurs after several days to weeks. All four larval instars are aquatic. Most larvae take in air through a pair of spiracles. In the Culex it is situated at the end of a small tube called a respiratory pupae are aquatic, motile and comma-shaped and bears a respiratory trumpets. After this stage, the adults emerge. Culex pipiens – house mosquito or rain barrel mosquito Aedes aegypti – yellow fever mosquito Anopheles gambiae – vector of human malaria Diseases transmitted by mosquitoes include equine encephalomyelitis, equine infectious anemia, anaplasmosis and microfilaria of dog heartworms. Mosquitoes could mechanically transmit fowl pox also. Control: 1. Proper drainage 2. Use of insecticides C. Ticks (giant mites) There are two families of ticks, the hard ticks (Ixodidae) and the soft ticks (Argasidae). Hard ticks have a rigid chitonous scutum while the soft ticks lack these structures. Ticks have different hosts. Becauses of local irritation, discomfort and blood loss, tick infestation causes loss of meat production, milk, wool and eggs. In infestation is severe enough ticks, can cause anemia. They transmit babesiasis, anaplasmosis, viral ad bacterial diseases. They are cause tick paralysis - a diseases of man and animals characterized by an acute ascending flaccid motor paralysis caused by tick bite. Life cycle of ticks: There are four development stages: eggs, larva, nymph and adult. All larvae have three pairs of legs and all nymphs and adults have four. 1. Argas persicus (fowl tick)  can cause anemia in birds and tick paralysis. 2. Boophilus microplus (tropical cattle tick)  can transmit babesia and anaplasma organisms. 3. Rhipcephalus sanguineus (brown dog tick)  can transmit babesiosis in dog and tick paralysis. Control: Use of organophosphate – spray or dipping 58 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s D. Mites Though like the ticks, mites are obligate parasites, they differ from them in the important respect that most species spend their entire life cycles from egg to adult on the host so that transmission is mainly by contact. 1. Demodex spp.  cause demodectic mange or follicular mange  they live in the hair follicles and sebaceous glands  microscopically it is “cigar-shaped”. 2. Sarcoptes scabei  it causes scabies in man and sarcoptic mange in animals  microscopically it is circular in shape  there is intense scratching and itching in affected animals. Poultry mites 1. Dermanyssus gallinae (red mite)  they are nocturnal feeders  they reduce egg production and weight gain of affected birds. 2. Ornithonyssus bursa (tropical fowl mite)  usually found on the fluff of the feathers especially on those around the vent. Control of mites:  spraying or dusting the birds and litter with insecticides/acaricide  spray the inside of the house and all hiding places, roosts, nest boxes, cracks, crevices with an effective insecticide/acaricide E. Lice Lice are highly host specific and are permanently ectoparasitic, most being unable to survive away from the host for more than a day or two. There are two kinds of lice: the sucking lice and the biting lice. Heavy infestation of suckling lice can cause severe anemia while both suckling and biting lice are a source of irritation and skin damage, which may lead to a loss of production and damage to hides. Life cycle of lice: The female lays eggs (nits), which are usually glued to the hair or feathers. The egg hatches into a nymph and after three molts the fully grown adult is present. 1. Biting Lice Poultry Biting Lice a. Menacanthus stramineus (yellow body louse)  occurs on the skin of the breast, thighs, anus and where there are relatively few feathers. 59 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  b. Cuclotogaster heterographus (head louse of poultry)  occurs on the skin and feathers of the head and neck. c. Lipeurus caponis (wing louse of chicken)  occurs on the underside of the large wing feathers. d. Columbicola (pigeon louse) Biting lice of mammals a. Damalinia bovis biting louse of cattle b. Damalinia ovis biting louse of sheep c. Damalinia caprae biting louse of goat 2. Suckling lice a. Haematopinus eurysternus short – nosed cattle louse b. Linognathus vituli long – nosed or blue louse of cattle c. Haematopinus tuberculatus sucking louse of buffalo F. Fleas Fleas are most important in dogs, cat and poultry. Their readiness to parasitize humans as alternative host givens them a relevance in public health. Fleas do not occur in horses, ruminants or pigs. Life cycle: The eggs are laid on the ground or on the host from which they soon drop off. There larva are maggot – like and a coat of bristles. They have chewing mouthparts and feed on debris and on the feces of the adult fleas, which contain blood and give the larvae a reddish color. The larva moults twice, the final stage then spins a cocon, a form of wolly puparium from which the adult emerges. 1. Ctenocephalides canis ad Ctenocephalides felis – common dog and cat fleas Intermediate host: Dipylidium caninum (common tapeworm of dog) ENDOPARASITES A parasite that lives within the body of the host. Parasitism is s form of symbiosis in which one organism (called parasite) benefits at the expense of another organism usually of different species (called host). This host-parasite association may eventuate to the injury of the host. Parasites may be grouped into ectoparasites and endoparasites. Parasites that live outside the host are called ectoparasites whereas those that live inside the host are called endoparasites. 60 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  Endoparasites are of two forms: intercellular parasites and intracellular parasites. Intercellular parasites are those that inhabit the spaces of the body of the host. Intercellular parasites are endoparasites that live within the cell of the host. Examples of intercellular parasites are nematodes, tapeworms, and other helminthes. Helminthes live in the gut of their hosts. Examples of intracellular parasites are the protozoan Plasmodium, the causative agent of malaria. They thrive inside the cells of their human host. Plasmodium species have different stages in their life cycle. Within the definitive host (human), the sporozoite stage of Plasmodium species occurs within the liver cells where the sporozoite gives rise to a merozoite or to a hyponozoite, which then infects the red blood cell of the host. A. Flukes (trematodes) A fluke is a common name given to parasitic flatworms of the class Trematoda (trematodes). This taxonomic class of phylum Platyhelminthes (flatworms) is characterized by having external suckers that they use to anchor themselves within their host. Life cycle of flukes: The adult lays eggs and in the egg the embryo develops into a pyriform (pear-shaped), ciliated larvae called a miracidium. The miracidium propels through the water by its cilia, does not feed and must find a suitable snail for its further development. It penetrates to the snail and develops into an elongated sac containing a number of germinal discs called a sporocyst. These cells develope into rediae. From the germinal cells of the rediae arise the final stages, the cercariae. The cercariae are young flukes with tail and they emerge actively from the snail. the cercariae swim for some time and then attach themselves to vegetation, shed their tails encyst, this stage is called metacercaria. 1. Schistosoma japonicum (blood fluke) Characteristics : Lives in the portal and mesenteric veins of both man and animals. It is also the intermediate hosts of water snails Infection is through skin penetration of cercaria. Clinical signs : Profuse diarrhea or dysentery, dehydration and anorexia, anemia with edema and a marked decrease in production or loss of weight Treatment : Praziquantel Control : Control of intermediate hosts using molluscicides (copper sulphate, niclosamide) Fencing of contaminated bodies of water and provide clean drinking water 2. Fasciola gigantica (liver fluke) Characteristics : Occurs in the bile ducts of cattle, sheep and other mammals. It is also the intermediate hosts of snail The metacerarcia occur on vegetation and host becomes infected through ingestion of the infected vegetation. 61 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s Clinical signs : Acute infections is characterized by disinfected painful abdomen with anemia and sudden death Treatment : Rafoxanide, oxyclozanide, albendazole Control : Elimination of intermediate host using mollusicides Biological control of intermediate hosts using ducks Rotational grazing 3. Paragonimus westermani (lung fluke) Characteristics : Occurs in the lungs and more rarely in the brain, spinal cord and other organs of pig, dogs, cat, ruminants, carnivores and man. First intermediate host: snail Second intermediate host: crab or crayfish Clinical signs : Infected animals become lethargic and there is an intermittent cough and dyspnea Treatment : Albendazole and bithional Control : Freshwater crustaceans should not be eaten raw and elimination of snails B. Tapeworms (cestodes) Tapeworms are intestinal parasites that are shaped like a tape measure. A parasite is an animal or plant that lives inside another animal or plant. Life cyle of tapeworms: The typical life cycle of these cestodes is indirect with one intermediate host. The adult is usually found in the small intestine of the final host, the segments and eggs reaching the exterior in the feces. 1. Diphylobothrium latum (broad fish tapeworm of carnivores) Characteristics : First intermediate host: copepod Second intermediate host: freshwater fish It competes with its host for food especially for vitamin B12 resulting to anemia Treatment : Praziquantel, Niclosamide Control : Freezing and cooking of fish and do not feed animals with raw fish 2. Dipylidium caninum (common tapeworm of dog and cat) Characteristics : Occurs in the small intestine of dog, cat, fox and occasionally man Intermediate host: dog and cat flea (Ctenocephalides canis and 62 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  Ctenocephalides felis) Mode of infection : through the ingestion of infected areas Treatment : Praziquantel Clinical signs : Anal scratching or scooting; in severe infection, the adult worms are passed out from the feces Control : Control intermediate host using acaricides 3. Raillietina tetragona Charcteristics : It is found in the posterior small intestine of chicken Intermediate host: Ants Clinical signs : Reduced growth rate and emaciation Treatment : Butyronate, Niclosamide Control : Control intermediate host using insecticides C. Roundworms (Nematodes) Life cycle of roundworms: During development, a nematode moults at intervals sheeding its include. In the complete life cycle, there are four moults, the successive larval stages being designated L1, L2, L3, L4 and finally L5, which is the immature adult. In the direct life cycle, the free-living larvae undergo two molts after hatching and infection is by ingestion of the free living L3. There are infections also by larval penetration of the skin or by ingestion of the egg containg a larva. In the indirect life cycle, the first two molts usually take place in an intermediate host and infection of the final host is either by ingestion of the intermediate host or by inoculation of the L3 when the intermediate host, such as a blood-sucking insect, feeds. After infection, two futher molts take place to produce the L5 or immature adult parasite. 1. Threadworms a. Strongyloides papillosus (Threadworm of ruminants) b. Strongyloides ransomi (Threadworm of pigs) Characteristics : Occurs in the small intestine Mode of infection : skin penetration, ingestion, prenatal infection Clinical signs : Diarrhea which soon becomes continuous hemorrhagic 63 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 2. Hookworms a. Ancylostoma caninum (hookworm of dog and other carnivores) Characteristics : Occurs in the small intestine Mode of infection : Ingestion of infected egg and skin penetration of larva Clinical signs : Anemia, edema, general weakness and emaciation, itching of the skin caused by penetration of larvae bloody feces Cutaneous larva migrans – condition that occurs in man and other hosts and is caused by the larvae of nematodes which enter the skin and migrate causing formation of papules and inflamed tracks sometimes with thickening of skin and pruritus. 3. Kidneyworm a. Stephanus dentatus (kidneyworm of swine) Characteristics : Occurs in the perirenal fat, kidney, liver, pancreas and other organs and muscles of pig Mode of infection : Ingestion and skin penetration Clinical signs : Failure to gain weight or in severe cases, weight loss and ascites if there is severe liver damage b. Dioctophyma renale (giant kidney worm) Characteristics : It is found in the kidney parenchyma of dog, fox and mink It is the largest parasitic nematode of domestic animals\ Mode of infection : Ingestion of infected annelid or paratenic host such as frog or fish Clinical signs : Dysuria with some haematuria especially at the end of micturition 4. Stomach worm a. Haemonchus contortus (barberpole worm or wireworm) Characteristics : Occurs in the abomasum of ruminants Clinical signs : Severe anemia, dark colored feces and sudden death due to acute blood loss. 5. Lungworm a. Dictyocaulus viviparous (lungworm of cattle) Characteristics : Occurs in the trachea, bronchi and bronchioles of cattle and buffaloes Clinical signs : Coughing, dyspnea 64 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s b. Metastrongylus apri (lungworm of swine) Characteristics : Occurs in the trachea, bronchi and bronchioles of pig Clinical signs : Persistent coughing 6. Ascarids a. Ascaris suum (common large worm of pig) Characteristics : Occurs in the small intestine of pig Mode of infection : Ingestion of infective egg Clinical signs : Coughing, stunted growth, pneumonia b. Neoascaris vitulorum (Toxocara vitulorum) Characteristics : Occurs in the small intestine of cattle and buffalo Mode of infection : Transplacental, transcolostral, ingestion Clinical signs : Diarrhea c. Toxocara canis Characteristics : Occurs in the small intestine of dog Clinical signs : Dull coat, often a “potbellied” appearance, mucod diarrhea, coughing, increased respiratory rate and a frothy nasal discharge. Visceral larva migrans – condition wherein larvae of ascaridoid nematodes migrate into tissues of animals. d. Toxascaris leonine Characteristics : Occurs in the small intestine of dog and cat Mode of infection : Ingestion of infective egg e. Ascaridia gali Characteristics : Occurs in the small intestine of chicken, turkey, goose Clinical signs : Hemorrhagic enteritis, anemia 65 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 7. Cecal worm a. Heterakis gallinarum (cecal worm of chicken) Characteristics : Occurs in the ceca of chicken Carrier of histomonas meleagridis (causal agent of blackhead) 8. Whipworm a. Trichruis suis (whipworm of swine) b. Trichruis vulpis (whipworm of dog) Characteristics : Occurs in the cecum and large intestine Clinical signs : Watery diarrhea which contains blood Treatment: 1. Levamisole 2. mebendazole 3. albendazole PROTZOAN DISEASES 1. Trypanosomiasis Causative agent : Typanosoma evansi – Surra Characteristics : Transmitted by blood sucking invertebrates These parasites of the circulatory systems and tissue fluids Clinical signs : Intermittent fever, anemia and weight loss Treatment : homidium chloride, quinapyramine, suramin Control : eradication of flies and use of prophylactic drugs 2. Histomoniasis (Histomonosis, infectious enterophepatitis or blackhead) Causative agent : Histomonas meleagridis Characteristics : Seen in turkeys, chicken and other gallinaceous birds Found in the ceca and liver Transmitted by cecal worm (Heterakis gallinarum) Clinical signs : Listlessness, dropping wings, unkempt feathers and sulfur- colored droppings Treatment : Nitroimidazoles 66 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 3. Cecal coccidiosis Causative agent : Eimeria tenella Clinical signs : Decreased growth rate to a high percentage of visibly sick birds, severe diarrhea and high mortality, involves the ceca with accumulation of blood and bloody droppings Control : vaccination and use of anti-coccidial drugs Treatment : amprolium, clopidol, salinomycin, sulfa drugs 4. Avian malaria Causative agent : Plasmodium vivax Transmission : Transmission through the bites of mosquitoes Clinical signs : It is characterized by weakness, lassitude, dyspnea, anemia, abdominal distention, ocular hemorrhage and death. Liver and spleen are markedly enlarged and often discolored (dark brown or black) Control : potentiated with primaquine or chloroquine in drinking water Treatment : Cloroquine VIRAL DISEASES OF POULTRY AND LIVESTOCK 1. Foot and Mouth Disease Foot and Mouth Disease (FMD) is a highly infectious viral infection of cattle, pigs, sheep, goats, buffalo and artiodactyls wildlife species. It is characterized by fever, vesicles in the mouth and on the muzzle, teats and feet and death in young animals. Causative agent : it is caused by an apthovirus belonging to picornavirus Transmission : by direct contact and aerosol Incubation period : 2-14 days depending on the infecting dose, susceptibility of the host and strain of virus Clinical signs : fever and shivering; smacking of the lips, salivation and stamping of the feet Vesicles develop on the tongue, dental pad, gums, lips and interdigital space and around the top of the claws and on the teats Control : 1. slaughter all affected and in-contact susceptible animals are slaughtered and burned and there is a strict restrictions on movement of animals and vehicles around infected premises 67 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  2. quarantine and vaccination there is a rigid quarantine of infected premises and immediate use of inactivated vaccine in all susceptible animals. 2. Rabies Rabies (Hydrophobia, le rage) this is an acute viral encephalomyelitis that affects all warm-blooded animals. It is disease of nervous system manifested as motor irritation with clinical signs of mania and paralysis Causative agent : rhabdovirus (Lyssavirus) Transmission : bites of a rabid animal via saliva rich in virus virus introduced into existing cuts or wounds on skin or through intact or abraded mucous membrane Incubation period : 21 – 80 days after exposure Clinical signs : there are three phases of the disease 1. Padromal Changes of behavior Animal stop eating and drinking and may seek solitude Frequent urination, erection in the male and sexual desire 2. Excitative (mad dog syndrome) Animal becomes irrational and viciously aggressive 3. Paralytic Paralysis of the throat or masseter muscles with profuse salivation and inability to swallow Paralysis progresses rapidly to all parts of the body and coma and death follows Control : comprehensive guidelines for control in dogs as prepared by WHO: 1. Notification of suspected cases and destruction of dogs showing clinical signs and dogs bitten by a suspected animal 2. Reduction of contact rates between susceptible dogs by leash laws, dog movement, control and quarantine 3. Mass vaccination of dogs 4. Stray dog control and destruction of unvaccinated dogs 5. Dog restriction 3. Hog Cholera (Classical Swine Fever, Swine Fever) Causative agent : pestivirus Transmission : it is transmitted by direct contact, accidental introduction of the virus through imported pig meat and meat products, mechanical transmission Symptoms : hemorrhages and cyanosis in the skin notably of the extremities Incubation period : 2-6 days Control : herd slaughter of infected pigs combined with are restriction on pig movement or vaccination 68 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 4. Fowl pox (Avian diptheria) Causative agent : pox virus Transmission : direct contact through abrasion of the skin Through the bite of mosquitoes Incubation period : 4-10 days 5. Infectious Bursal Disease (Gumboro disease) Causative agent : birnavirus Transmission : virus is shed in the feces and transferred from house to house by fomites Incubation period : 3 – 4 days Lesions : Bursa of farbicius is swollen, edematous, yellowish and occasionally hemorrhagic congestion and hemorrhages on the pectoral, thigh and leg muscles Clinical signs : sub-clinical infections – could be seen in birds affected before 3 weeks of age and characterized by severe, long lasting immunosuppression clinical infections – chickens exhibit severe prostration, incoordination, watery diarrhea, soiled vent feather, vent picking and inflammation of the cloaca Control : vaccination 6. Pseudorabies (Aujesky’s Disease, Mad Itch) Causative agent : herpesvirus Transmission : the virus could be transmitter through aerosol or direct with infected animals Clinical signs : swine: dyspnea and sneezing and there are nervous sings like tremors and paddling ruminants: there is intense pruritus on one of the flanks or the hindlegs but it maybe on any part of the body Control : vaccination 7. Transmissible gastroenteritis (TGE) it is a common viral disease of the small intestine that causes vomiting and profuse diarrhea in pigs of all ages Causative agent : coronavirus Incubation period : ~ 18 hours Transmission : it spreads easily by aerosol or contact exposure Clinical signs : vomiting is the initial sign followed by profuse watery diarrhea, dehydration and excessive thirst. Gestating sows occasionally abort and lactating sows often exhibit vomiting diarrhea and agalactia Control : vaccination of sows 69 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 8. Contagious ecthyma (Orf, Sore mouth) it is an infectious dermatitis of sheep and goats that affects primarily the lips of young animals. The diseases is usually severe in goats than in sheep Causative agent : pox virus (parapoxvirus) Transmission : it is transmitted by direct contact with infected animals or by contact with contaminated soil, equipment or feed and water troughs Clinical signs : formation of papules and vesicles that rapidly change to pustules and finally by the appearance of heavy scabs. With their thickned, stiff, sensitive lips, affected lambs or kids can neither suckle nor graze and rapid emaciation occurs. Healing is complete in about 1 month and by this time, scabs have fallen off and left the lips smooth without scabs. Control : vaccination 9. Avian influenza (fowl plague, Fowl pest) it is an acute, highly fatal disease of chicken, turkeys, pheasants and certain wild birds. Causative agent : orthomyxovirus Incubation period : few days to one week Clinical signs : the birds have high body temperature, lost its appetite and become lethargic. There are whitish, necrotic areas on the comb and wattle. Affected birds have greenish diarrhea, cyanosis and edema of the head, comb and wattle and a blood-tinged oral and nasal discharges. Control : vaccination 10. Prochine Reproductive and Respiratory Syndrome (PRRS) Causative agent : arterivirus Transmission : direct contact with infected pig Clinical signs : it has two distinct phases: Reproductive phase – includes increase in the number of stillborn piglets, mummified fetuses, premature farrowing’s and weak born piglets. There is increase in pre-weaning mortality respiratory phase – piglets born develop a characteristics thumping respiratory pattern Control : vaccination of piglets and non-pregnant sows BACTERIAL DISEASES OF POULTRY AND LIVESTOCK 1. Pullorum disease (Bacillary White Diarrhea) this is a highly fatal disease of young chicks during the first few days of life but older chicks are more resistant. Causative agent : Salmonella pullorum 70 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s Transmission : transmission is chiefly through the egg but could also be transmitted by direct or indirect contact Symptoms : affected chicks usually huddle near a source of heat, do not eat, appears sleepy and show whitish fecal pasting around the vent Treatment : Furazolidone, sulfa-trimethoprim 2. Hemorraghic septicemia it is an acute pasteurellosis manifested by an acute and highly fatal septicemia principally in cattle and water buffalo Causative agent : pasteurella multocida Transmission : infection occurs by direct or indirect contact. Natural infection occurs by ingestion or inhalation Symptoms : animals first exhibit dullness, then reluctance to move, fever, salivation and serous nasal discharge. There is edematous swelling in the throat region, parotid region, neck and brisket. Treatment : sulfanomides, tetracycline, penicillin and chloramphenicol Control : vaccination 3. Fowl cholera it is a contagious widely distributed diseases that affects domestic and wild birds. Causative agent : Pasteurella multocida Transmission : thru excretion from mouth, nose and conjunctiva of birds Symptoms : In acute cases, there is fever, depression, anorexia, mucoid discharge from the mouth, ruffled feather, diarrhea and increase respiratory rate. In chronic form, there is swollen wattles, joints and tendon sheaths Treatment : sulfanomides Control : vaccination 4. Brucellosis (Contagious abortion, Bang’s Disease) this is a contagious disease primarily affecting cattle, pig, sheep, goats and dogs characterized by abortion, orchitis and infection of the accessory sex gland in males. The disease in man is referred to as undulant fever. Causative agent : Brucella abortus (cattle) and Brucella sp (depending on the species) Transmission : natural transmission occurs by ingestion, venereal transmission and through artificial insemination also occurs. Organism may also enter the body through mucous membranes, conjunctiva, wounds or even intact skin. Symptoms : abortion is the most obvious manifestation. Infection may also cause stillborn or weak offspring’s, retained placenta and reduced milk yield. Orchitis and infection of accessory sex glands in males are also observed Treatment : no effective treatment Control : testing the whole herd using a serological test and determine the reactors is best Vaccination (cattle) 71 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 5. Mastitis it is the inflammation of the mammary gland almost always due to the effects of infection by bacterial or mycotic pathogens Causative agent : Staphylococcus aureus; Staphylococcus agalactiae; coliforms; Staphylococcus dysgalactiae and corynebacterium pyogenes Transmission : transmission is through direct contact with infected animals Symptoms : there are four forms of the disease: 1. Peracute – swelling, heat pain and abnormal secretion in the gland with fever. 2. Acute – changes in the gland are similar to peractue but fever, anorexia nad depression are slight to moderate 3. Sub-acute – no systemic changes and changes in the gland and its secretion are less marked 4. Sub-clinical – inflammatory reaction is detectible only by tests Treatment : penicillin, cloxacillin, erythromycin 6. Erysipelas (Diamond skin disease) Characteristics : it is an infectious diseases mainly of growing pigs Causative agen : Erysipelothrix rhusiopathiae Transmission : Transmission is through direct contact with infected animals Symptoms : There are four forms of the disease: 1. Acute septicemia – pigs die suddenly without previous signs. This is usually occurs in finishing pigs 2. Skin (sub-acute) – there is skin discoloration of the ears, snout and abdomen 3. Valvular endocarditis – common in mature or young adult pigs and frequently manifest by death usually from embolism 4. Chronic arthritis – pigs can’t walk because of swollen joints Treatment : penicillin Control : Vaccination 7. Infectious coryza it is an acute or sub-acute respiratory disease characterized by nasal discharge sneezing and swelling of the face under the eyes. Causative agent : Haemophilus paragallinarum Transmission : by direct contact, airborne droplets and contamination of drinking water Incubation period : 1 – 3 days Symptoms : severe swelling of one or both infraorbital sinuses with edema of the surrounding tissues which close one or both eyes Treatment : erythromycin and oxytetracyline Control : follow an all-in-all-out program with sound management 72 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 8. Blackleg it is an acute febrile disease of cattle and sheep characterized by emphysematous swelling usually in the heavy muscles Causative agent : Clostridium chauvoei Transmission : ingestion of spores in soil or bones of dead infected carcasses Symptoms : acute lameness, depression and fever are early signs. Characteristics : edematous and crepitant swelling develop in the hip, shoulder, chest, back, neck and elsewhere Treatment : penicillin Control : vaccination 9. Malignant edema it is an acute generally fatal toxemia of cattle, horse, sheep goats and pigs. Causative agent : Clostridium septicum Transmission : infection occurs through contamination of wound containing devitalized tissue. Symptoms : local lesions are soft swellings that pit on pressure and extend rapidly because of formation of large quantities of exudates that infiltrate subcutaneous tissue and intramuscular connective tissues of affected animals Treatment : penicillin and other broad spectrum antibiotics Control : vaccination 10. Tetanus (Lock jaw) this is a toxemia caused by a specific neurotoxin produced by Clostridium tetani in necrotic tissues. Almost all animals are susceptible to this disease although dogs and cats are much resistant. Birds are quite resistant while horses are the most sensitive. Causative agent : Clostridium tetani Transmission : it is introduced to deep puncture wounds Incubation period : 10 – 14 days Symptoms : in horse, ears are erect, the tail stiff and elevated and nostrils dilated and prolapse of the third eyelids. Spasms of the neck and back muscles cause extension of the head and neck white stiffness of leg muscles cause the animal to assume “sawhorse stance” Treatment : tetanus antitoxin and penicillin or other broad-spectrum antibiotics Control : tetanus toxoid 11. Botulism (Limberneck) it is a food poisoning marked by progressive paralysis caused by ingestion of a toxin of Clostridium botulinum Causative agent : Clostridium botulinum Transmission : ingestion of toxin found in food. Maggots can mechanically transmit the toxin. 73 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s Symptoms : there is paralysis of muscles, distributed vision, dysphagia (difficulty in swalling) and generalized progressive weakness. Limberneck is the common name of botulism described as neck paralysis Treatment : no successful treatment Control : collection and disposal of dead birds Fly control may reduce risk of toxic maggots in the environment Disinfection around poultry house 12. Anthrax (Splenic fever, Charbon, Milzbrand) it is an acute, febrile diseases of virtually all warm-blooded animals including man. It is an septicemia characterized principally by a rapid fatal course. In man it is called Malignant carbuncle and Woolsorter’s diseases Causative agent : Bacillus anthracis Transmission : Animals may become infected when eating contaminated feedstuffs or meat. It could also be transmitted through direct contact and aerosol. Symptoms : there are three forms of the disease: 1. Peracute – characterized by sudden onset and rapidly fatal course 2. Acute – there is rise in body temperature and period of excitement followed by depression, stupor, respiratory or cardiac distress, bloody discharge from the natural body openings. 3. Chronic – localized, subcutaneous, edematous swelling that could be extensive involving parts of the ventral neck, thorax and shoulders. Treatment : penicillin and oxytetracyline (early stage) Control : 1. notification of the appropriate regulatory officials 2. rigid enforcement of quarantine 3. prompt disposal of dead animals, manure, beddings or other contaminated materials by burning or deep burial 4. Isolation of sick animals and removal of healthy animals from the contaminated areas 5. Disinfection of stables, pens, milking barns and equipment used on livestock 6. Use of insect repellants 7. Control of scavengers that feed on dead animals 8. Observation of general sanitary procedures by people who contact diseases animals both for their own safety and to prevent the spread of the disease. 13. Colibacillosis this is a disease common in pigs few days of age under intensified rearing system. Causative agent : Escherichia coli Transmission : it is transmitted through direct contact and ingestion of the bacteria Symptoms : 1. Peracute coliform septicemia – causes death within several horse with or without diarrhea. Affected pigs are weak and cold. 74 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  2. Enteric collibacillosis – characterized by bright yellow pastings to watery feces Treatment : Restoration of fluid and electrolyte balance and use of antibiotics (quinolones, neomycin, gentamycin, ampicillin) Control : the incidence of neonatal diarrhea can be lowered by: 1. Proper sanitation practices 2. Provide adequate colostrum within the first hours of life 3. Vaccination of sows FUNGAL DISEASE AND METABOLIC DISORDERS FUNGAL DISORDERS 1. Aspergillosis (Brooder pneumonia, mycotic pneumonia, pneumomycosis) this is a disease usually of the respiratory system, of avian species Causative agent : Aspergillus fumigatus Transmission : chicks and poults may become infected during hatching as a result of inhaling larger number of spores. In older birds, infection is caused primarily by inhalation of spore-laden dust from contaminated litter or feed or dusty range areas. Symptoms : there is dyspnea, gasping, polypnea, anorexia and emaciation and increased thirst, torticollis and other nervous signs. Treatment : no successful treatment Control : strict adherence to sanitation procedures in the hatchery and avoid moldy litter. METABOLIC DISORDERS 1. Milk fever (Parturient paresis, hypocalcemia) it is an afebrile disease of mature dairy cows that occurs most commonly at or soon after parturition and is manifested by circulatory collapse, generalized paresis (partial paralysis) and depression of consciousness). Causative agent : the exact cause is unknown. It is associated with the sudden onset of profuse lactation in mature cows. During this time, there is a sudden drop of serum calcium because of the milk produced. Symptoms : usually, it occurs within 72 hours of parturition. Cows are able to stand but show signs of hypersensitivity and excitability. Also observed are fine tremors over the flank and loins and display ear twitching and head bobbing. Later on, cows are unable to stand and in sternal recumbency with subnormal body temperature and cold extremities. Cows lose consciousness and leads to coma and death. Treatment : calcium gluconate give slow IV Control : Feeding diets low in calcium and normal to high phosphorous during late pregnancy and giving of vitamin D 75 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 2. Bloat (Ruminal tymphany) it consists of accumulation of excessive gas distending the rumen to a dangerous degree. Types : Primary or frothy bloat or primary ruminal tymphany – the cause is entrapment of the normal gases of fermentation in a stable foam. It is common to animals grazing legume or legume dominant pasture. It is also common in feedlot cattle given high grain diets. Secondary ruminal tymphany or free gas bloat – physical obstruction of eructation occurs from esophageal obstruction caused by a foreign body, stenosis or pressure from enlargement outside the esophagus. Clinical Signs : in acute cases, there is sudden death of the animal. The rumen is greatly distended and bulges – especially of the upper left flank. There is dyspnea and accompanied by mouth breathing. Treatment : trocar and cannula; rumenotomy; antifoaming agent – vegetable and mineral oil; dioctyl sodium sulfosuccinate ANTI-MICROBIAL ACTIVITY Chemotheraphy – refers to the use of drugs and chemical (chemotherapeutic agents) to treat or prevent diseases caused by infectious organisms and by cancerous cells Classification of chemotherapeutic agents: 1. Antibacterial (antibiotics) – used against bacteria 2. Antifungal – used against fungi 3. Anti-parasitic – used against internal and external parasites a. Anti-protozoans b. Anthelmintics or dewormers c. Insecticides or acaricides 4. Anti-viral – used against viruses Antibiotics. It is a substance that has capability to kill or suppress the growth of diseases forming organisms. The beneficial effect on the use of antibiotics is either killing the bacteria or just stopping their growth. Considerations when animal is treated with a chemotherapeutic agent: 1. animal 2. drug 3. pathogen Classification of antibacterial agents A. Classification according to spectrum of activity 1. Drugs primarily effective against gram positive cocci and bacilli (narrow spectrum activity): a. penicillin b. cloxacillin 76 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  c. macrolides (erythromycin, tylosin), d. lincosamides (lincomycin) e. bacitracin 2. Drugs primarily effective against aerobic gram negative bacilli (narrow spectrum activity): a. aminoglycosides – (streptomycin) b. polymixin (polymixin b, colistin) 3. Drugs that are relatively broad-spectrum and affecting both gram positive and gram negative bacilli: a. ampicillin b. amoxicillin c. sulfa-trimethroprim d. chloramphenicol e. quinolones – enrofloxacin f. nitrofurans g. tetracycline h. neomycin i. gentamycin B. Classification according to effect on bacteria 1. Bactericidal (it kills the bacteria): a. penicillin b. aminoglycosides (streptomycin, gentamycin, neomycin) c. sulfa-trimethoprim d. polymixins e. quinolones 2. Bacteriostatic (it inhibits the growth and replication of bacteria): a. tetracycline b. chloramphenicol c. macrolides d. lincosamides e. nitrofurans f. sulfonamides ANTISEPTICS AND DISINFECTANTS Antiseptics - it is preparations that are applied to living tissues that kill or prevent the growth of microorganisms. Disinfectants - it is preparations applied to inanimate objects that prevent infection by destruction of pathogenic microorganisms. Sanitizer- it is a special form of disinfectant that is capable of reducing the number of microbial contaminants to levels considered safe by public health requirement. 77 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s Types of antiseptic and disinfectants 1. Alkalis they have a ph of 9 or higher which is detrimental to the survival of most microorganisms; these are not used on living tissues. a. Sodium hydroxide - can be used against anthrax bacillus and hog cholera virus. b. Quicklime - added to water with which it reacts to form calcium hydroxide and used to cover carcasses when burying them. 2. Acids used frequently as preservatives for food or feed because they prohibit the growth of microorganisms. acids a. (acetic acid and lactic acid) b. Boric acid used as antiseptic wash for the eye. 3. Phenols and related compounds a. Phenol it is bacteriostatic in low concentration; irritating to living tissues. b. Cresol frequently used to disinfect trucks, pens and railways cars. it is more active than phenols. 4. Halogens a. Chloreine it is used in the sterilization of water supplies, treatment of sewage water and sterilization of daily equipment. b. Iodine one of the most effective antiseptics for use on the skin. iodine solutions make excellent washes in which to soak instruments between their uses on successive animals. iodine 5. Alcohols a. ethyl alcohol b. isopropyl alcohols 6. Oxidizing agents a. Hydrogen peroxide generally available at 3% aqueous solution; it is used mostly for washing and cleansing wound. b. Permanganate used as antiseptic and antifungal; the most common is potassium permanganate which is used in conjunction with formaldehyde to fumigate buildings. 7. Other disinfectants and antiseptics a. quarternary ammonium compounds are goods disinfectants for use against non-spore forming bacteria and used primarily as equipment rinse and spray disinfectant b. detergents and wetting agents used extensively as cleaning agents because they are non-toxic to living tissues. 78 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s  c. soaps used to remove oily compound and organic matter; often used to remove bacteria from the skin. ANTHELMENTICS AND ACARICIDES Acaricides are preparations that destroy external parasites in animals. Anthelmintics are preparations that kill or eliminate intestinal worms. Strategies being used in a parasite control program: 1. to minimize interaction between the parasite and the host  (reducing the total population of parasites in the external and internal environment of the host to minimize potential infection of the latter) 2. to improve the nutritional status of the host  animal in a high level of nutritional status can develop stronger protective mechanism. it can also resist better the harmful effects of parasitism) Methodologies to prevent heavy exposure of susceptible hosts to parasites: A. Environmental Control 1. control of intermediate hosts  destruction of the intermediate host and their breeding places reduces their population and thus break the life cycle of the parasites) 2. sanitation and hygienic measures  these are applied to the habitat of the host to control and eradicate vulnerable stages of the life cycle of the parasite. 3. grazing management  effective grazing management can minimize the seeding of the area with the infective stages of the parasite B. Regular Deworming Program The the aim is to eliminate or reduce the parasite load of the animal by applying effective drugs or herbal preparations Guidelines in Regular Deworming Program: 1. the species or type of parasites should be identified before treatment 2. regular dosing of the animals at appropriate intervals is necessary to prevent the establishment of adult parasite load capable of doing harm to the animal. 3. young animals are more susceptible than mature ones to the effects of parasitism 4. regular manual removal of ectoparasites in ruminants maybe very effective in light infestation. in heavy infestation, appropriate insecticide/acaricide application should be done 5. a regular deworming/delousing/deticking program is more often effective if coupled with control of the parasite in the environment 79 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s Acaricides that can be used: 1. carbamates 2. chloronated hydrocarbons 3. ivermectin 4. organophosphates 5. pyrethroids anticoccidials: 1. amprolium 2. clopidol 3. sulfonamides 4. dichlorvos antiprotozoans: 1. pyrimethamine 2. imidocarb antinematodals: 1. albendazole 2. fenbendazole 3. mebendazole 4. oxfenbendazole 5. febantel 6. levamisole 7. piperazine antitrematodals: 1. niclofan 2. closantel 3. rafoxanide 4. albendazole anticestodals: 1. praziquantel BIOSECURITY Quarantine is based on a system of enclosure in which the organisms is enclosed within its habitat and prevented from getting out or exclosure in which it is exclosed from a habitat that is free. Types 1. Simple Quarantine it is done by separating animals by as much as two fences so direct contact cannot be made by animals. simple quarantine 80 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s 2. Absolute quarantine it involves separate attendants or the same with disposable foot cover, disposable gloves, separate feed pans, ropes etc. 3. Official qurantine it is imposed by a licensed authority of a state, province etc. it may be a simple or absolute depending on the disease in question. official quarantine quarantine line can be established, this could be a fence or two spaced apart by a distance varying from a few yards to many times or simply a line marked on a map between two areas, one of which the organism is known to inhabit and the other known to be free. Attempts are then made to prevent the organism crossing from one to the other, generally by preventing the movement of livestock from the infected to the non-infected area. Natural barrier such as mountain, oceans or rivers may also be defined as quarantine lines. In almost all cases, the quarantine line is supplemented by patrols whose duty is to see the quarantine is maintained. Often area is declared a quarantine area and attempts made to enclose the organism with that area. These are usually intended to deal with an outbreak of a specific diseases in which case they are temporary and the quarantine maybe lifted the disease has been cleared. Sometimes the whole country maybe declared a quarantine area. Similarly, the reverse when an area or a country is exclosed from surrounding infected areas or countries.  81 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s References: Berry, J. G. 2017. Livestock Disease: Cause and Control. Oklahoma State University https://extension.okstate.edu/fact-sheets/livestock-disease-cause-and-control.html Cunningham, J.G. and B.G. Klein， 2007,. Textbook of Veterinary Physiology. 4th ed. St. Louis, Elsevier,. De Lahunta, A. 1983. Veterinary Neuroanatomy and Clinical Neurology. 2nd ed. Philadelphia, W.B. Saunders, Dellman, H.D., and J.A. Eurell. 1998., Textbook of Veterinary Histology. 5th ed. Baltimore Lippincott, Williams & Wilkins, Frandson, Lea, and Febiger,. 1981. Anatomy and physiology of farm Animal. Philadelphia Frandson, R.D, W. Lee Wilke, And A. Dee Fails, n.a., Anatomy and Physiology of Farm Animals, seventh edition, a Jhn Wiley Sons, Inc., Publication. pdf https://www.biologyonline.com/dictionary/endoparasite 82 | A n a t o m y , P h y s i o l o g y a n d D i s e a s e s o f F a r m A n i m a l s