BCSE (Basic & Clinical Sciences Examination) · USA / Canada · ICVA; administered through CVMA-NEB and AVMA-ECFVG
Original practice questions written to the published syllabus · not past papersPoisoning by metals, plants, mycotoxins, pesticides, non-protein nitrogen, venoms and pollutants, with residues in food and the antidotes used.
In the exams: AVE Paper 1 toxicology at least 3; SAVC toxicology 10 (plus southern African plant poisonings); ICAR AIEEA-PG 13 Unit IV (poisonous plants, agro-chemicals); ICAR AICE-JRF core group 07
NAVLE and BCSE (North America)
Small-animal emergencies (anticoagulant rodenticides, bromethalin, cholecalciferol, xylitol, grapes, permethrin in cats, metaldehyde, ethylene glycol, chocolate), decontamination decisions, ionophores in horses, nitrate and cyanide in cattle, and interpreting clotting and cholinesterase tests.
How our questions for BCSE spread across the units of Veterinary Toxicology. Difficulty: 9 easy, 26 medium, 3 hard.
| Antidotes | 6 | |
| Rodenticide poisoning | 4 | |
| Corrosives and irritants | 3 | |
| Oxalate, lantana and bracken poisoning | 3 | |
| Mycotoxins and aflatoxicosis | 3 | |
| Snake bite and insect stings | 3 | |
| Metal toxicity: lead, arsenic and mercury | 2 | |
| Cyanogenic plants | 2 | |
| Nitrate and nitrite poisoning | 2 | |
| Organophosphate and carbamate poisoning | 2 | |
| Organochlorine and pyrethroid poisoning | 2 | |
| Water-borne toxicities | 2 | |
| Copper, molybdenum, fluorine and selenium toxicity | 1 | |
| Urea and non-protein nitrogen toxicity | 1 | |
| Radiation hazards | 1 | |
| Ecotoxicology and residues | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Several ewes fed a cattle concentrate for months suddenly become depressed, jaundiced and pass red-brown urine after being trucked to a show. Necropsy shows a yellow-orange friable liver and dark 'gunmetal' kidneys. Which sample best confirms the cause?
D. Liver copper concentration
This is the haemolytic crisis of chronic copper poisoning triggered by stress. Liver copper reflects the accumulated burden; blood copper is high only briefly during the crisis.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Why is emesis contraindicated after a dog drinks kerosene?
D. Distillates are easily aspirated, causing chemical pneumonitis
Low-viscosity hydrocarbons are readily aspirated during vomiting and cause severe pneumonitis. They are not corrosive alkalis, and charcoal binds them poorly.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
A horse is found dead in a paddock where hedge clippings were dumped. Leaf fragments in the stomach are flat, dark-green needles. The toxin involved is
A. Taxine alkaloids from yew
Yew (Taxus) clippings kill horses within hours through taxine blockade of cardiac sodium and calcium channels; horses are the most sensitive species.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Prepubertal gilts fed mouldy maize show swollen, reddened vulvas and some rectal prolapses. The most likely mycotoxin is
D. Zearalenone
Zearalenone binds oestrogen receptors, producing hyperoestrogenism. Deoxynivalenol causes feed refusal and vomiting; fumonisin causes porcine pulmonary oedema.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
A cat develops generalised tremors, ear flicking and hyperthermia a few hours after its owner applied a dog flea spot-on. The most likely toxicant is
C. Permethrin
Concentrated canine permethrin spot-ons poison cats, which glucuronidate poorly. The other drugs are used in products licensed for cats.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
A dog ate a second-generation anticoagulant bait 2 hours ago and emesis produced bait. If vitamin K1 is started, how is the end of treatment decided?
D. Finish the course (about four weeks), then check PT 48 to 72 hours after the last dose
Second-generation compounds persist for weeks, so treatment is long and its adequacy is checked by PT 48 to 72 hours after stopping; a normal day-1 PT is expected and proves nothing.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Within minutes of a bee sting a dog collapses with vomiting and hypotension. The first drug to give is
C. Adrenaline (epinephrine)
This is anaphylaxis; adrenaline reverses vasodilation and bronchoconstriction. Antihistamines and corticosteroids are adjuncts.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Which practice follows the ALARA principle when taking radiographs?
C. Chemical restraint and collimation so no hands are in the primary beam
ALARA uses time, distance and shielding; lead gloves do not protect hands in the primary beam, so restraint is chemical or mechanical.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
The withdrawal period of a veterinary drug is
C. Time from last dose until meat, milk or eggs are usable, with residues below the MRL
The withdrawal (withholding) period is set so residues fall below the maximum residue limit; it applies to the labelled species, dose and route.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Why is vitamin K3 (menadione) not used for anticoagulant rodenticide poisoning?
A. It is too slow to restore clotting factors and is nephrotoxic in horses
Vitamin K1 (phytonadione) is required; menadione does not restore factor synthesis effectively and causes renal damage in horses.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Ten here, 38 in the app. The Laisha app has every practice question we have written to BCSE in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
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