Ruminant Strongylida Lecture 3 2024 PDF

Strongylida Dr Nur Mahiza Md Isa 07 November 2024 Ruminant Strongyles Contents Life cycle of ruminant strongyle Epidemiology and Diagnosis PGE Haemonchus contortus Trichostrongylus Oesophagostomum Cooperia Pathogenesis PGE 2023 VPM3353 Dr Nur Mahiza 3...

Strongylida Dr Nur Mahiza Md Isa 07 November 2024 Ruminant Strongyles Contents Life cycle of ruminant strongyle Epidemiology and Diagnosis PGE Haemonchus contortus Trichostrongylus Oesophagostomum Cooperia Pathogenesis PGE 2023 VPM3353 Dr Nur Mahiza 3  General Life-cycle of Ruminant Strongyles PARASITIC L3→L4→Adult exsheathed PREPARASITIC L3 7 days L2 L1 2023 VPM3353 Dr Nur Mahiza 4 *http://www.imagecyte.com/animations/haem.html  General Epidemiology & Pathogenesis of Parasitic Gastro-Enteritis (PGE) PGE is a disease complex associated with a number of nematode species (mostly strongyles) either singly or in combination PGE is characterized mainly by diarrhoea & weight loss (clinical disease) or less than optimum production (subclinical disease) RUMINANT STRONGYLES (Degree of Prevalence) Haemonchus (90%) Trichostrongylus (60%) Oesophagostomum (30%) VPM3353 Dr Nur Mahiza 5  DIAGNOSIS OF PGE History The number of animals infected (usually > 1) Age (usually < 6 mths) but sometimes animal > 6 mths may also beaffected when stressed Nutritional factor Stocking density as predisposing factor (↑ density, ↑ risk) Drenching of anthelmintic (type, method, dose, potency, expiry date etc.) Clinical signs Thin (loss of protein & loss of cells) No appetite and emaciated VPM3353 Dr Nur Mahiza 6 3. Post-mortem findings - in fresh carcass (1500 epg Subclinical PGE : FEC 500-1500 epg - Blood: Haematocrit Centrifugation Technique (HCT) to obtain the PCV & determine whether the animal is anaemic or hypoproteinaemic VPM3353 Dr Nur Mahiza 7 Types of Strongyles Characteristics Haemonchus -also known as ‘barber’s pole’ worm -found in the abomasum (important in sheep & cattle) -the intestines (straight) are coiled spirally by the uterus -anterior has a large lancet at the mouth & cervical papillae -posterior has a copulatory bursa; female has a vulval flap -L3 has a cone-shaped tail that is separated from the sheath in a ‘V’ shaped manner VPM3353 Dr Nur Mahiza 8  Haemonchus contortus In abomasum, ‘stomach worm’ or ‘barber’s pole worm’, 2-3cm long Route of infection is by ingestion of grasses or herbage infected with L3 Prepatent period is 3-4weeks Adult remove blood from the host by sucking & seepage from biting sites, causing anaemia & hypoalbuminaemia VPM3353 Dr Nur Mahiza 9 VPM3353 Dr Nur Mahiza 10  Trichostrongylus and Cooperia In small intestine of ruminants, 0.5cm long L3 tunnels beneath epithelium, L4 bursts out into lumen of SI causing enteritis, erosion of villi surface & protein losses VPM3353 Dr Nur Mahiza 11  Types of Strongyles Characteristics Trichostrongylus -has a simple head with no buccal capsule -the opening of the excretory pore is easily seen at the anterior oesophageal region of the adult worms -females have a tapered tail & are missing a vulva flap -males are readily identified by their spicules -found in the abomasum or small intestine -L3 has short and stubby tail encapsulated by a sheath VPM3353 Dr Nur Mahiza 12  Types of Strongyles Characteristics Cooperia -has small cephalic vesicle & the transverse cuticular striations in the oesophageal region -spicules usually have a distinct wing-like expansion in the middle region & often bears ridges -females usually have a small vulval flap & a long tapering tail -found in the small intestines -L3 has a pair of refractile eye piece at the head region VPM3353 Dr Nur Mahiza 13  Oesophagostomum In large intestine of ruminants, stout worms 1.2cm long Route of infection is by ingestion of grasses or herbage infected with L3 L3 enters deep into mucosa causing inflammation & nodule formation, L4 emerges causing ulceration VPM3353 Dr Nur Mahiza 14  Types of Strongyles Characteristics Oesophagostomum -has small buccal capsule -found in large intestines -in most species, the buccal capsule is surrounded by leaf crowns -presence of an inflated cuticular cephalic vesicle around the anterior oesophagus which terminates at the cervical groove -some has cervical papillae -L3 has a cone-shaped tail that is encapsulated by a thin, long & filamentous sheath VPM3353 Dr Nur Mahiza 15 Pathogenesis Pathogenesis of Haemonchus contortus A. Anaemia -understanding of the Kinetics of Erythropoeisis Normal Sheep Sheep with 2000 Haemonchus -blood volume = 1500-2000ml -1 worm sucks 0.05ml/day 2000 worms sucks 100ml/day -daily breakdown -daily loss Hb→3g Hb→15g Fe→10mg Fe→50mg *Fe absorption from gut almost NIL Head Vulval flap VPM3353 Dr Nur Mahiza 17 B. Malabsorption & maldigestion 1) L4 L4 L5 Non-functional cells Parietal cells (gastric gland) to secrete HCl for digestion ↓ No HCl ADULT ↑ pH in stomach disrupts enzymatic Haemonchus reaction & causes protein maldigestion 2) Cell junction Pepsinogen leaked into bloodstream *Blood pepsinogen level can be evaluated to detect gastritis & stomach ulcer Plasma proteins leaked into lumen Normal epithelial cell VPM3353 Dr Nur Mahiza Replacement cells 18  3) Loss of parietal cells HCl↓ pH↑ pepsinogen pepsin - Effect on bacterial flora →the low pH within the stomach enables the normal flora to replicate & prevents other bacteria from over-multiplying →When pH is high, replication of normal flora will be disrupted while other bacteria can over-populate the stomach - Loss of cellular integrity Protein leakage→Hypoalbuminaemia Can be detected →Increased plasma pepsinogen in blood 19 VPM3353 Dr Nur Mahiza  3) Loss of parietal cells HCl↓ pH↑ pepsinogen pepsin - Effect on bacterial flora →the low pH within the stomach enables the normal flora to replicate & prevents other bacteria from over-multiplying →When pH is high, replication of normal flora will be disrupted while other bacteria can over-populate the stomach - Loss of cellular integrity Protein leakage→Hypoalbuminaemia Can be detected →Increased plasma pepsinogen in blood VPM3353 Dr Nur Mahiza 20  Pathogenesis of Trichostrongylus Sloughing villus Migration crypts Mitosis Normal Villi Normal Villus VPM3353 Dr Nur Mahiza 21  Pathogenesis of Trichostrongylus →MALABSORPTION Shedding Villus atrophy accelerated crypts Mitosis inadequate Parasitised Parasitised 22 VPM3353 Dr Nur Mahiza Pathogenesis of Oesophagostomum -causes sloughing of villi Naïve/Inexperience Animal Experienced Animal OESOPHAGUS OESOPHAGUS L3 L3 1st time L3 Body immune L3 being L3 system can introduced in recognized the body & L3 as foreign manage to bodies & penetrate back mount an into the lumen inflammatory response L4 L4 (infiltration of inflammatory cells) leading to formation of haemorrhagic nodules. most L3 L5 cannot return into the lumen ADULT LARGE INTESTINE VPM3353 Dr Nur Mahiza LARGE INTESTINE 23 2023 VPM3353 Dr Nur Mahiza 24 Class Nematoda Characteristics: 1) unisexual; female bigger than males 2) 5 larval stages (L1, L2, L3, L4 & L5) 3) majority of nematodes are in the GIT Group Morphology Life Cycle & Larval Migration Site Infective Stage Rhabditida very small, -direct blood-lungs-tracheal small slender, 0.5cm -L3 via skin migration intestine Strongylida 0.5-2.5cm -direct no migration except GIT (Strongyle) -L3 via ingestion hookworms (hepatic- except tracheal migration) hookworms (L3 via skin) Enoplida 4-6cm -direct no migration intestines (Enoplids) -L1 @ ova Ascaridida large, white, -direct blood-liver-lungs- small (Ascarids) 10-40cm -L2 @ ova tracheal migration intestine Spirurida 6-8cm -indirect limited or no GIT (Spirurids) -L3 in insects migration Filarida 6-30cm -indirect tissue migration blood (Filarids) -L3 inoculated by vessels 2023 mosquito orMahiza VPM3353 Dr Nur fly etc.25  Question 1 The fecal sample in the device at your place came from a 4-year-old male Rottweiler as part of his yearly check-up. Examine the sample and identify the eggs of the parasite (give genus and species) VPM3353 Dr Nur Mahiza 26 Question 2 A saturated salt flotation was done on a fecal sample from a 4 month old Puppy which has been brought to you for its first check-up. The results of this test are shown under the microscope. Identify the parasite egg (give Genus and species 27