All Free Veterinary Science MCQs with Answers

• A. Hair follicles
• B. Stratum corneum
• C. Sebaceous glands
• D. Subcutaneous tissue

Explanation: Sarcoptes scabiei burrows within the stratum corneum and causes intense itching and crust formation.

• A. L1 rhabditoid larva
• B. Adult male
• C. L3 filariform larva
• D. Unembryonated egg

Explanation: The L3 filariform larva is the infective stage of Strongyloides and may penetrate the skin or be ingested.

• A. Lungs and bronchioles
• B. Stomach and abomasum
• C. Bile ducts and gall bladder
• D. Caecum and colon

Explanation: Adult Trichuris vulpis attaches to the mucosa of the caecum and colon. Its characteristic bipolar-plugged eggs are passed in faeces and…

• A. Across the tegument
• B. Through specialised nephridia
• C. By phagocytosis at the scolex
• D. Through an alimentary canal

Explanation: Cestodes lack a digestive tract and absorb nutrients across their metabolically active tegument.

• A. Acetylcholinesterase
• B. Glutamate-gated chloride channels
• C. Folate synthesis
• D. Fungal ergosterol synthesis

Explanation: Ivermectin increases chloride ion conductance through glutamate-gated chloride channels in parasite nerve and muscle cells, causing…

• A. It supports multiplication of only larval stages
• B. It carries the parasite only during embryonation
• C. It harbours the parasite's adult or sexual stage
• D. It transmits the parasite without harbouring it

Explanation: A definitive host contains the adult stage or the stage in which sexual reproduction occurs.

• A. A blood-feeding hard tick
• B. A freshwater aquatic snail
• C. A terrestrial dung beetle
• D. A free-living oribatid mite

Explanation: Moniezia expansa requires an oribatid mite, in which its larval cysticercoid develops.

• A. A fully sporulated oocyst
• B. A newly shed unsporulated oocyst
• C. A ruptured oocyst wall
• D. A free merozoite in water

Explanation: Sporulation produces the infective sporozoites within the Eimeria oocyst.

• A. Baermann larval recovery
• B. Faecal sedimentation
• C. Perianal tape examination
• D. Direct blood smear

Explanation: Fasciola eggs are relatively heavy, so sedimentation is more reliable than routine flotation.

• A. Small intestinal lumen
• B. Bile ducts and gall bladder
• C. Bronchi and bronchioles
• D. Urinary bladder

Explanation: Adult Dictyocaulus viviparus occupy the bronchi and bronchioles of cattle, where they interfere with airflow and cause respiratory…

• A. The biting midge
• B. The louse fly
• C. The hard tick
• D. The flea

Explanation: Flea larvae ingest Dipylidium eggs, and the cysticercoid develops inside the flea.

• A. A direct life cycle without an intermediate host
• B. An indirect life cycle requiring a snail
• C. A vector-borne cycle requiring a tick
• D. A cycle requiring a fish intermediate host

Explanation: Ascaris suum has a direct life cycle, although its eggs must embryonate in the environment before becoming infective.

• A. To concentrate heavy trematode eggs
• B. To recover active nematode larvae
• C. To identify protozoal oocysts by staining
• D. To detect antibodies against adult worms

Explanation: The Baermann technique uses larval movement through water to recover living nematode larvae from faecal material.

• A. Salicylanilides
• B. Macrocyclic lactones
• C. Benzimidazoles
• D. Imidazothiazoles

Explanation: Benzimidazoles bind parasite beta-tubulin and interfere with microtubule assembly, reducing nutrient uptake and energy production.

• A. Filarial nematodes
• B. Cestode helminths
• C. Acarine ectoparasites
• D. Apicomplexan protozoa

Explanation: Cystoisospora species are intracellular apicomplexan protozoa that multiply in intestinal epithelial cells.

• A. Transplacental migration from the dam
• B. Ingestion of eggs from soil
• C. Penetration through the skin
• D. Inoculation by biting flies

Explanation: Dormant Toxocara canis larvae in the bitch are reactivated during pregnancy and cross the placenta into developing puppies.

• A. The feeding trophozoite
• B. The resistant cyst
• C. The immature oocyst
• D. The tissue schizont

Explanation: The resistant cyst survives outside the host and is the infective stage ingested in contaminated water or food.

• A. Portal vein and liver
• B. Bile ducts and gall bladder
• C. Pulmonary arteries and right heart
• D. Urinary bladder and kidneys

Explanation: Adult Dirofilaria immitis occupy the pulmonary arteries and, in heavy infections, may extend into the right side of the heart.

• A. It completes feeding only inside the intestine
• B. It remains permanently attached to feathers
• C. It burrows deeply into the host skin
• D. It feeds mainly at night and hides by day

Explanation: The poultry red mite leaves cracks and crevices at night to take blood meals, then returns to hiding places during the day.

• A. Ileocaecal junction
• B. Oesophageal entrance
• C. Pyloric sphincter
• D. Rectal opening

Explanation: Anoplocephala perfoliata attaches around the ileocaecal junction and may contribute to ileocaecal inflammation or obstruction.