Free Veterinary Parasitology MCQs with Answers

• 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.

• A. They require a snail host first
• B. They are usually infective immediately
• C. They must sporulate inside muscle
• D. They mature only after a tick bite

Explanation: Cryptosporidium oocysts are generally fully sporulated and infective when excreted, allowing direct faecal oral transmission.

• A. Five pairs
• B. Four pairs
• C. Three pairs
• D. Six pairs

Explanation: Tick larvae have three pairs of legs, whereas nymphs and adults have four pairs.

• A. Oocysts in drinking water
• B. Blood parasites per millilitre
• C. Larvae per square centimetre
• D. Faecal eggs per gram

Explanation: The McMaster technique uses a calibrated flotation chamber to estimate the number of helminth eggs or coccidian oocysts per gram of…

• A. The larval metacestode stage
• B. The adult intestinal stage
• C. The free-living larval stage
• D. The sexually mature oocyst stage

Explanation: A hydatid cyst is the larval metacestode of Echinococcus granulosus developing in an intermediate host such as a sheep.

• A. Complete immunity to the parasite
• B. Egg shedding by adult reproductive worms
• C. Death of all tissue larvae
• D. Absence of environmental contamination

Explanation: A high faecal egg count usually indicates that mature female worms are producing and shedding eggs into the intestine.

• A. Dogs and other canids
• B. Sheep and other ruminants
• C. Cats and other felids
• D. Pigs and wild boars

Explanation: Sexual reproduction of Toxoplasma gondii occurs in the intestinal cells of felids, which therefore act as definitive hosts.

• A. Time required for egg embryonation
• B. Time from detection until clinical recovery
• C. Time between two parasite generations
• D. Time from infection until parasite detection

Explanation: The prepatent period is the interval between acquisition of infection and the first reliable detection of the parasite or its products.

• A. One individual host
• B. Two host species
• C. Three host species
• D. No vertebrate host

Explanation: In a one-host tick, the larva, nymph and adult remain on the same individual host while successive stages develop.

• A. A single negative faecal test
• B. Repeated faecal examinations
• C. A blood smear showing gametocytes
• D. A skin scraping showing mites

Explanation: Giardia cysts may not be shed continuously, so examining faecal samples collected on different days improves detection.

• A. Formation of the eggshell
• B. Production of digestive enzymes
• C. Attachment to the intestinal wall
• D. Development of the larval bladder

Explanation: The scolex is the attachment organ of a tapeworm and may carry suckers, hooks or both.

• A. A parasite develops without a host
• B. A parasite infects two unrelated host species
• C. A vector acquires infection from the environment
• D. The host becomes reinfected by its own parasite stages

Explanation: Autoinfection occurs when infective stages produced by a parasite reinfect the same host without requiring transmission from another…

• A. They commonly have a single-cell embryo when passed
• B. They always contain a fully formed hexacanth embryo
• C. They are produced only inside arthropods
• D. They lack any protective outer covering

Explanation: Many nematode eggs are passed at an early stage and contain a single cell or developing embryo.

• A. It kills adult worms inside the host
• B. It reduces exposure to infective larvae
• C. It prevents all eggs from being shed
• D. It replaces anthelmintic treatment completely

Explanation: Moving animals to less contaminated pasture can reduce the number of infective larvae they ingest.

• A. Earthworm
• B. Freshwater snail
• C. Land snail
• D. Oribatid mite

Explanation: Muellerius capillaris develops through larval stages in terrestrial gastropods, especially land snails and slugs.

• A. Urinary bladder wall
• B. Small intestine lumen
• C. Bronchi of the lungs
• D. Bile ducts of the liver

Explanation: Adult Fasciola hepatica occupies the larger bile ducts, where it feeds and produces eggs that pass through the bile into the intestine.