Free Veterinary Pharmacology MCQs with Answers
60 Veterinary Pharmacology MCQs from Veterinary Science, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Covers how drugs act in animals, including pharmacokinetics, pharmacodynamics, routes of administration, dosage forms, adverse effects and drug interactions. Major groups include antimicrobials, antiparasitics, analgesics, anaesthetics, anti-inflammatory drugs, hormones and cardiovascular medicines, with attention to withdrawal periods and species differences.
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60 questions · page 3 of 3
- A. 50S subunit
- B. 40S subunit
- C. 30S subunit
- D. 60S subunit
Explanation: Chloramphenicol binds the 50S bacterial ribosomal subunit and inhibits peptidyl transferase activity.
Correct answer: 50S subunit- A. Highly soluble complexes
- B. Poorly absorbed chelates
- C. Rapidly hydrolysed esters
- D. Strongly acidic metabolites
Explanation: Tetracyclines bind calcium and form poorly absorbed chelates in the gastrointestinal tract.
Correct answer: Poorly absorbed chelates- A. Muscarinic M2 receptor
- B. Beta-2 adrenergic receptor
- C. Alpha-1 adrenergic receptor
- D. Nicotinic Nn receptor
Explanation: Acepromazine blocks alpha-1 adrenergic receptors, producing peripheral vasodilation and possible hypotension.
Correct answer: Alpha-1 adrenergic receptor- A. GABA-A receptor
- B. Histamine H1 receptor
- C. Opioid mu receptor
- D. Dopamine D2 receptor
Explanation: Metoclopramide mainly reduces vomiting through dopamine D2 receptor antagonism in the chemoreceptor trigger zone.
Correct answer: Dopamine D2 receptor- A. Anticoagulant rodenticide
- B. Bromethalin rodenticide
- C. Cholecalciferol rodenticide
- D. Zinc phosphide rodenticide
Explanation: Vitamin K1 restores the production of functional clotting factors depleted by anticoagulant rodenticides.
Correct answer: Anticoagulant rodenticide- A. GABA chloride channels
- B. Nicotinic acetylcholine receptors
- C. Serotonin 5-HT1 receptors
- D. Muscarinic acetylcholine receptors
Explanation: Levamisole stimulates nematode nicotinic acetylcholine receptors, producing sustained contraction followed by paralysis.
Correct answer: Nicotinic acetylcholine receptors- A. Cyclooxygenase
- B. Monoamine oxidase
- C. Phosphodiesterase
- D. Acetylcholinesterase
Explanation: Aminophylline, a theophylline preparation, inhibits phosphodiesterase and increases intracellular cyclic AMP, promoting bronchial smooth…
Correct answer: Phosphodiesterase- A. Quaternary ammonium compound
- B. Small inorganic electrolyte
- C. Highly water-soluble sugar
- D. Highly lipid-soluble acidic drug
Explanation: Many lipid-soluble acidic drugs bind extensively to albumin, so displacement by another drug can temporarily increase the free active…
Correct answer: Highly lipid-soluble acidic drug49. Which adverse effect is classically associated with excessive digoxin administration in animals?
- A. Cardiac arrhythmias
- B. Severe bone marrow aplasia
- C. Permanent cataract formation
- D. Acute pancreatic rupture
Explanation: Digoxin toxicity commonly produces gastrointestinal signs and potentially serious cardiac arrhythmias because it alters myocardial…
Correct answer: Cardiac arrhythmias- A. Complete renal filtration
- B. A smaller free fraction in plasma
- C. Rapid entry into cerebrospinal fluid
- D. Unrestricted tissue penetration
Explanation: Only the unbound fraction of a drug is readily available for distribution, metabolism and renal filtration.
Correct answer: A smaller free fraction in plasma- A. Dopamine
- B. Glutamic acid
- C. Gamma-aminobutyric acid
- D. Norepinephrine
Explanation: Benzodiazepines enhance gamma-aminobutyric acid activity at GABA-A receptors, increasing neuronal inhibition.
Correct answer: Gamma-aminobutyric acid52. Sulfonamide antibacterials inhibit bacterial growth primarily by blocking which metabolic pathway?
- A. Cholesterol formation
- B. Peptidoglycan breakdown
- C. Bile acid synthesis
- D. Folate synthesis
Explanation: Sulfonamides inhibit dihydropteroate synthase, an enzyme required for bacterial folate synthesis.
Correct answer: Folate synthesis- A. Fomepizole
- B. Praziquantel
- C. Naloxone
- D. Protamine
Explanation: Fomepizole inhibits alcohol dehydrogenase and prevents formation of toxic ethylene glycol metabolites.
Correct answer: Fomepizole- A. Ligand-gated chloride channel
- B. Voltage-gated sodium channel
- C. Voltage-gated calcium channel
- D. ATP-sensitive potassium channel
Explanation: Pyrethroids delay closure of voltage-gated sodium channels, causing repetitive nerve firing and paralysis in susceptible arthropods.
Correct answer: Voltage-gated sodium channel- A. One half-life
- B. Two half-lives
- C. Four to five half-lives
- D. Ten to twelve half-lives
Explanation: For drugs with first-order elimination, about 94 to 97 percent of steady state is reached after four to five half-lives.
Correct answer: Four to five half-lives- A. Collecting duct concentration
- B. Glomerular filtration
- C. Tubular reabsorption
- D. Tubular secretion
Explanation: Active tubular secretion moves some drugs from peritubular capillaries into the renal tubular lumen for excretion.
Correct answer: Tubular secretion- A. Acidic urine
- B. Alkaline urine
- C. Neutral plasma
- D. Alkaline bile
Explanation: Weak bases become more protonated and ionized in acidic urine, which reduces passive tubular reabsorption and may increase excretion.
Correct answer: Acidic urine- A. Receptor down-regulation
- B. Receptor up-regulation
- C. Permanent enzyme inhibition
- D. Reduced drug absorption
Explanation: Long-term receptor blockade can cause compensatory up-regulation or increased sensitivity of receptors.
Correct answer: Receptor up-regulation- A. Enrofloxacin
- B. Amikacin
- C. Erythromycin
- D. Sulfadiazine
Explanation: Erythromycin binds the 50S subunit and interferes with bacterial translocation during protein synthesis.
Correct answer: Erythromycin- A. Desmopressin
- B. Vitamin K1
- C. Fomepizole
- D. Protamine sulfate
Explanation: Protamine sulfate forms an inactive complex with heparin and reverses its anticoagulant action.
Correct answer: Protamine sulfate