ICAR AIEEA (PG): Master's entrance, Veterinary Science and Animal Sciences · India · NTA for ICAR
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
ICAR AIEEA-PG (Code 13, Unit IV: Pharmacology & Toxicology)
Poisonous plants (cyanogenic, nitrate, oxalate, Lantana, bracken), agro-chemicals (organophosphates, carbamates, organochlorines, pyrethroids), urea toxicity, metal toxicity (lead, arsenic, copper, fluoride), aflatoxins, and matching each poison to its mechanism and antidote.
How our questions for ICAR AIEEA spread across the units of Veterinary Toxicology. Difficulty: 21 easy, 25 medium, 5 hard.
| Metal toxicity: lead, arsenic and mercury | 5 | |
| Oxalate, lantana and bracken poisoning | 5 | |
| Copper, molybdenum, fluorine and selenium toxicity | 4 | |
| Nitrate and nitrite poisoning | 4 | |
| Mycotoxins and aflatoxicosis | 4 | |
| Urea and non-protein nitrogen toxicity | 4 | |
| Ecotoxicology and residues | 4 | |
| Organophosphate and carbamate poisoning | 3 | |
| Water-borne toxicities | 3 | |
| Radiation hazards | 3 | |
| Corrosives and irritants | 2 | |
| Cyanogenic plants | 2 | |
| Organochlorine and pyrethroid poisoning | 2 | |
| Rodenticide poisoning | 2 | |
| Snake bite and insect stings | 2 | |
| Antidotes | 2 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Why is thiamine given together with calcium disodium EDTA to cattle with lead poisoning?
B. Improves clinical response and reduces tissue lead deposition
Thiamine has been shown to improve the response of lead-poisoned cattle and reduce tissue lead; it is not a chelator. EDTA-induced hypocalcaemia is prevented by using the calcium salt of EDTA, not by thiamine.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
A forage contains 1% potassium nitrate (KNO3) on a dry-matter basis. What is its nitrate (NO3) content?
B. About 0.61%
NO3 is 62.0 of KNO3's 101.1 g/mol, i.e. 61.3%; 1% × 0.613 ≈ 0.61% NO3. 1.64% inverts the factor; 0.14% would be nitrate-N in KNO3.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
In Lantana poisoning, photosensitisation occurs because
B. Cholestasis blocks biliary excretion of phylloerythrin, which reaches the skin
This is hepatogenous (secondary) photosensitisation: phylloerythrin from chlorophyll accumulates when the liver cannot excrete it. Hypericin causes primary photosensitisation (St John's wort).
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Aflatoxins are produced mainly by
C. Aspergillus flavus and A. parasiticus
Aspergillus flavus and A. parasiticus produce aflatoxins on groundnuts, maize and cottonseed. Claviceps produces ergot; Fusarium graminearum zearalenone and deoxynivalenol.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Equine leukoencephalomalacia, liquefactive necrosis of cerebral white matter in horses, is caused by
C. Fumonisins from Fusarium verticillioides
Fumonisins disrupt sphingolipid metabolism and cause ELEM in horses and pulmonary oedema in pigs. Lolitrem B causes ryegrass staggers.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Organophosphates produce toxicity mainly by
A. Inhibiting acetylcholinesterase
OPs phosphorylate acetylcholinesterase, so acetylcholine accumulates at synapses. GABA-A block is the action of cyclodiene organochlorines.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Why are organochlorine insecticides such as DDT restricted internationally?
D. They persist, are stored in fat and biomagnify up food chains
Lipophilic, persistent organochlorines bioaccumulate and biomagnify; the Stockholm Convention restricts them. Their low water solubility is the opposite of rapid leaching into groundwater.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Groundwater naturally high in which element is a major livestock and human problem in parts of Bangladesh and West Bengal?
D. Arsenic
Geogenic arsenic in shallow tube-well water affects people and livestock in the Bengal delta.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
LD50 is best defined as
A. The statistical dose that kills 50% of a test group by a set route and time
LD50 is a quantal measure of acute lethality. The ED50 is the effective dose in 50%, and the highest dose without adverse effect is the NOAEL.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Why is the calcium salt of EDTA used for lead poisoning, not disodium EDTA?
C. Disodium EDTA chelates blood calcium and causes hypocalcaemic tetany
Calcium disodium EDTA exchanges its calcium for lead; disodium EDTA would strip calcium from the blood.
Further reading: Gupta, Veterinary Toxicology (3rd ed.); Merck Veterinary Manual, Toxicology
Ten here, 51 in the app. The Laisha app has every practice question we have written to ICAR AIEEA 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.
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