Special Veterinary Pathology

GROSS SPECIMENS

Nematode infections

• Parascaris equorum –Horse
• Verminous bronchopneumonia
• The larvae break through the capillaries and alveolar walls leading to haemorrhages and necrosis
• Heavy infestation is associated with extensive pulmonary edema and interstitial emphysema.
• Dirofilariasis –Heart –Dog
• The filarial parasite is mainly found in right ventricle of heart,less often in left auricle, pulmonary artery and vena cava causing compensatory hypertrophy and enlargement of the right ventricle.
• Oesophagostomiasis - Pimply gut·
• The lesions give the intestine nodular appearance as they thickened the wall and project from the serosal surface
• The nodules may be calcified and encapsulated
• Ancylostomiasis - Intestine – Dog
• The hook worms attached to the mucosa of the intestine and leave small denuded areas in the epithelium which appear as haemorrhages and bleed continously
• Onchocercosis –Aorta –Cow
• Tortuous elevated streaks and cysts are noticed in the aorta
• Spirocercosis – Esophagus nodule –Dog
• One or several nodules are seen on the luminal surface of oesophagus usually few cms from the cardia of stomach
• One or several worms may be embedded in each nodule and parts of worms protrude from a small orifice
• Spirocercosis – Aorta –Aneurysm –Dog
• Tumour like nodules are seen in the aortic wall which initiate the formation of aneurysm with possible rupture and fatal haemorrhage
• Habronemiasis –Stomach –Horse
• Worms present on the mucosa cause mild catarrhal gastritis and small erosions and ulcers.
• Sometimes they may produce nodules or tumours

Cestode infecions

• Hydatid cyst - Liver - Cow
• Hydatid cyst - Heart - Bullock

Trematode infections

• Liver fluke infection – Liver - Cattle
• Migration tracts are found in the liver in initial stage
• Amphistomiasis – Pylorus – Calf
• Amphistomiasis – Rumen – Cattle
• Schistostomiasis – Nasal mucosa - Cattle

Protozoal rickettsial  diseases

• Theileriosis - Abomasum – Cow
• Abomasum show erosions and characteristic “punched out “ulcers.
• Theileriosis - Kidney - Cow
• The kidney characteristically show small grayish-white infarcts.
• The nodular accumulation of the cells causes atrophy of renal tubules.
• Theileriosis - Lymph node – Cattle
• They are enlarged,edematous and may show haemorrhages
• Trypanosomosis – Splenomegaly - Dog