Free Veterinary Pathology MCQs with Answers

• A. Immune mediated vasculitis
• B. Chronic bacterial abscesses
• C. Ischemic brain injury
• D. Fat necrosis of the pancreas

Explanation: Fibrinoid necrosis occurs when immune complexes and plasma proteins damage vascular walls, producing a bright eosinophilic appearance.

• A. Hepatic icterus
• B. Prehepatic icterus
• C. Posthepatic icterus
• D. Mixed icterus

Explanation: Prehepatic icterus results from excessive red cell destruction, which produces more bilirubin than the liver can immediately process.

• A. Nuclear transcription system
• B. Lysosomal digestive system
• C. Sodium and potassium pump
• D. Collagen synthesis pathway

Explanation: Failure of the ATP dependent sodium and potassium pump causes sodium and water to accumulate inside the cell.

• A. Antibody mediated tissue injury
• B. Persistent blood circulation
• C. Excessive collagen formation
• D. Endogenous enzymatic digestion

Explanation: Autolysis is the self digestion of cells by enzymes released from their own lysosomes after death.

• A. Antibodies against specific antigens
• B. Acid fast dyes against bacterial walls
• C. Enzymes that dissolve collagen
• D. Electrolytes that precipitate calcium

Explanation: Immunohistochemistry uses labelled antibodies that bind selected antigens in cells or tissues.

• A. Reduced total bone mass
• B. Defective mineralization of osteoid
• C. Excessive formation of dense bone
• D. Fibrous replacement of bone tissue

Explanation: Osteomalacia is defective mineralization of newly formed osteoid in mature bone.

• A. Persistent ketonuria
• B. Severe bilirubinuria
• C. Marked proteinuria
• D. Profound hypoglycemia

Explanation: Glomerular amyloid disrupts the filtration barrier and commonly produces heavy protein loss in urine.

• A. Canine mast cell tumor
• B. Canine multicentric lymphoma
• C. Canine osteosarcoma
• D. Canine transmissible venereal tumor

Explanation: Canine transmissible venereal tumor spreads by physical transfer of viable neoplastic cells, usually during sexual contact.

• A. Corynebacterium pseudotuberculosis
• B. Listeria monocytogenes
• C. Bacillus anthracis
• D. Salmonella Dublin

Explanation: Corynebacterium pseudotuberculosis causes chronic abscesses in lymph nodes and internal organs of sheep and goats, producing caseous…

• A. Tips of mature villi
• B. Crypt epithelium
• C. Muscularis externa
• D. Serosal connective tissue

Explanation: Canine parvovirus targets rapidly dividing crypt epithelial cells, causing crypt necrosis and subsequent villous collapse.

• A. Size of individual parenchymal cells
• B. Amount of extracellular fluid
• C. Number of cells within a tissue
• D. Volume of intracellular fat

Explanation: Hyperplasia results from increased cell division, producing more cells in a tissue.

• A. Masson's trichrome
• B. Oil Red O
• C. Prussian blue
• D. Toluidine blue

Explanation: Toluidine blue stains mast cell granules metachromatically because of their sulfated glycosaminoglycans.

• A. Grocott methenamine silver
• B. Ziehl-Neelsen stain
• C. Wright-Giemsa stain
• D. Alcian blue stain

Explanation: Grocott methenamine silver strongly outlines fungal walls and makes hyphae readily visible.

• A. Ecchymosis
• B. Petechia
• C. Hematoma
• D. Suffusion

Explanation: Petechiae are very small, pinpoint hemorrhages caused by leakage from small vessels.

• A. Thrombus formation without vessel injury
• B. Smooth muscle hypertrophy without inflammation
• C. Fibrinoid change with nuclear debris in vessel walls
• D. Amyloid deposition around arterial nerves

Explanation: Leukocytoclastic vasculitis shows inflammation of small vessels with fragmented leukocyte nuclei, often accompanied by fibrinoid necrosis.

• A. A blood clot lodged within a nutrient artery
• B. A cavity filled with newly formed cartilage
• C. A benign tumour arising from bone marrow
• D. A fragment of dead bone separated from living bone

Explanation: A sequestrum is devitalized bone that becomes separated from surrounding viable bone, commonly during chronic osteomyelitis.

• A. Pyogranulomatous inflammation with serosal effusion
• B. Purely suppurative inflammation of the skin
• C. Diffuse mineralization of skeletal muscle
• D. Necrotizing inflammation limited to the hoof

Explanation: Feline infectious peritonitis commonly produces pyogranulomatous inflammation and protein-rich effusion in abdominal or thoracic serous…

• A. A clear watery fluid on an intact serosa
• B. A fibrinonecrotic membrane attached to mucosal surfaces
• C. A localized collection of pus in a capsule
• D. A diffuse increase in tissue blood flow

Explanation: Diphtheritic inflammation causes mucosal necrosis followed by deposition of fibrin, producing a firmly attached fibrinonecrotic membrane.

• A. Local supply of adipose tissue
• B. Entire original population of mature cells
• C. Underlying basement membrane and stromal framework
• D. Surrounding layer of skeletal muscle

Explanation: An intact basement membrane and stromal framework guide the migration and organization of surviving epithelial cells during regeneration.

• A. Lamellar bone with normal osteocytes
• B. Mature cartilage without cellular atypia
• C. Uniform fat cells between bone trabeculae
• D. Neoplastic cells producing malignant osteoid

Explanation: Malignant osteoid produced directly by atypical neoplastic cells is the defining histological feature of osteosarcoma.