All Free Veterinary Science MCQs with Answers

Every Veterinary Science question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

758 questions · page 26 of 38

  • 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.

Correct answer: They are usually infective immediately
  • 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.

Correct answer: Three 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…

Correct answer: Faecal eggs per gram
  • 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.

Correct answer: The larval metacestode stage
  • 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.

Correct answer: Egg shedding by adult reproductive worms
  • 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.

Correct answer: Cats and other felids
  • 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.

Correct answer: Time from infection until parasite detection
  • 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.

Correct answer: One individual host
  • 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.

Correct answer: Repeated faecal examinations
  • 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.

Correct answer: Attachment to the intestinal wall
  • 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…

Correct answer: The host becomes reinfected by its own parasite stages
  • 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.

Correct answer: They commonly have a single-cell embryo when passed
  • 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.

Correct answer: It reduces exposure to infective larvae
  • 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.

Correct answer: Land snail
  • 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.

Correct answer: Bile ducts of the liver
  • A. Complete metamorphosis
  • B. Incomplete metamorphosis
  • C. Direct development without larvae
  • D. Alternation between two hosts

Explanation: Fleas pass through egg, larva, pupa and adult stages, which is complete metamorphosis.

Correct answer: Complete metamorphosis
  • A. They commonly infect every mammalian host
  • B. They are usually strongly host specific
  • C. They require a tick for transmission
  • D. They normally alternate between birds and mammals

Explanation: Most Eimeria species develop in particular host species or closely related hosts, so identification often depends on both parasite…

Correct answer: They are usually strongly host specific
  • A. Inhibition of folate synthesis
  • B. Disruption of tegument through bile salts
  • C. Spastic paralysis through nicotinic receptors
  • D. Blockage of parasite mitochondrial respiration

Explanation: Levamisole acts as a nicotinic acetylcholine receptor agonist at the nematode neuromuscular junction, producing sustained contraction and…

Correct answer: Spastic paralysis through nicotinic receptors
  • A. Large eggs among red cells
  • B. Motile larvae in plasma
  • C. Cysts within leukocyte nuclei
  • D. Intraerythrocytic piroplasms

Explanation: Babesia multiplies inside red blood cells and appears as intraerythrocytic piroplasms, sometimes in paired or tetrad forms.

Correct answer: Intraerythrocytic piroplasms
  • A. Feather debris and skin material
  • B. Blood from damaged capillaries
  • C. Bile from the gall bladder
  • D. Lymph within subcutaneous tissue

Explanation: Menopon gallinae has chewing mouthparts and feeds on feathers, skin scales and tissue debris on poultry.

Correct answer: Feather debris and skin material