Veterinary Pathology
Veterinary Pathology
This domain tests disease mechanisms and lesions: cell injury, inflammation, necrosis, neoplasia, circulatory disturbances, and post-mortem interpretation.
Core rules
- Cell injury may be reversible or lead to necrosis or apoptosis; morphology depends on tissue and insult.
- Inflammation has vascular and cellular phases; neutrophils dominate acute lesions, macrophages and lymphocytes chronic lesions.
- Necrosis types: coagulative, caseous, liquefactive, fat, fibrinoid, gangrenous.
- Neoplasia is classified by tissue of origin and behaviour; invasion and metastasis indicate malignancy.
- Post-mortem changes include rigor mortis, livor mortis, and autolysis; distinguish from ante-mortem lesions.
Worked example
A lung lesion is firm, grey-white, and crumbly, with a granulomatous rim. Reasoning: crumbly cheese-like material is caseous necrosis. In cattle or guinea pigs, this suggests tuberculosis. The rim indicates chronic inflammation. Confirm with Ziehl-Neelsen staining and culture; do not diagnose from gross lesion alone.
Traps
- Calling caseous necrosis coagulative because both are firm.
- Confusing post-mortem autolysis with acute inflammation.
- Diagnosing neoplasia without histopathology.
- Ignoring species-specific lesion patterns and zoonotic risk at necropsy.
Exam focus
Describe lesion location, size, colour, consistency, and distribution. Link each lesion to a mechanism and a likely cause.