Parasitology Quiz 28 Quiz InstructionsThis quiz consists of 20 multiple-choice questions.You will be awarded 5 marks for each correct answer. Question 1: At what dose has primaquine diphosphate been shown to cause mortality in cats when evaluated for activity against Babesia felis?Above 0.1 mg/kgAbove 0.5 mg/kgAbove 1.0 mg/kgAbove 5.0 mg/kg Question 2: Which vitamin does the anticoccidial drug amprolium structurally resemble, acting as its competitive antagonist in rapidly dividing coccidian cells?Vitamin B12 (cobalamin)Vitamin B1 (thiamine)Vitamin B6 (pyridoxine)Vitamin B2 (riboflavin) Question 3: Allopurinol, a pyrazolpyrimidine used alone or in combination with meglumine antimonate to treat canine leishmaniosis, acts by inhibiting which enzyme?Dihydrofolate reductaseXanthine oxidaseDihydropteroate synthaseThymidylate synthase Question 4: What is the primary cellular target of the trypanocidal drug quinapyramine, whose disruption leads to the displacement of magnesium ions and polyamines?Mitochondrial electron transport chainCytoplasmic ribosomesDihydrofolate reductaseMicrotubule assembly machinery Question 5: To which chemical class of antiprotozoals does the compound toltrazuril belong?Symmetrical triazoneAsymmetrical triazonePyridinol derivativeIsoquinoline derivative Question 6: Which of the following phenanthridium derivatives was replaced in clinical veterinary practice due to a high incidence of delayed toxicity, including severe liver damage and local reactions?Isometamidium chlorideHomidium bromideDimidium bromideQuinapyramine methyl sulphate Question 7: Long-term administration of salinomycin in turkeys, even at or below recommended doses, can result in which of the following toxic manifestations?Severe growth retardation and wet litter from altered water excretionExcitement, paralysis of head and legs, and deathSevere cutaneous eruptions and acute liver failureBilateral blindness and chronic renal failure Question 8: In faecal flotation methods, what is the required specific gravity of the flotation solution to successfully float the heavier eggs of trematodes?1.10–1.201.20–1.251.30–1.351.45–1.50 Question 9: Which polyether ionophore is classified as a 'divalent' ionophore due to its ability to complex divalent cations such as calcium and magnesium?MonensinNarasinSalinomycinLasalocid Question 10: Why are many of the complexities of drug resistance selection seen in diploid organisms absent during the selection of anticoccidial resistance in asexual stages of Eimeria?These stages reproduce exclusively via sexual conjugation, bypassing mutation.These asexual stages are haploid, so mutants are immediately selected.The oocysts have thick, impermeable walls that prevent drug penetration.Asexual stages lack ribosomes, which are the main target of resistance genes. Question 11: Match the drug with its corresponding target parasite or clinical application:Column I:1. Clopidol2. Halofuginone3. Carnidazole4. QuinacrineColumn II:A. Cryptosporidiosis in calvesB. Eimeria spp in chickensC. Giardia and PlasmodiumD. Trichomoniosis in pigeons1-B, 2-A, 3-D, 4-C1-C, 2-B, 3-A, 4-D1-B, 2-D, 3-A, 4-C1-D, 2-A, 3-B, 4-C Question 12: Match the trypanocidal drug with its standard dosage rate and route as described in the text:Column I:1. Suramin2. Diminazene aceturate3. Homidium bromide4. Isometamidium chlorideColumn II:A. 3.5–7 mg/kg IMB. 10 mg/kg IV (Mainly T. evansi in camels)C. 0.25–0.5 mg/kg IMD. 1 mg/kg IM (Potentially carcinogenic, dissolve in hot water)1-B, 2-A, 3-D, 4-C1-A, 2-B, 3-C, 4-D1-B, 2-C, 3-D, 4-A1-C, 2-A, 3-B, 4-D Question 13: Match the pesticide resistance management approach with its correct description:Column I:1. Management by saturation2. Management by moderation3. Management by multiple attackColumn II:A. Uses only the minimum control necessary to ensure susceptible genes are never completely eliminated.B. Involves alternating or rotating insecticides with different modes of action or alternating chemical with non-chemical tactics.C. Heavy or frequent use of a pesticide designed to leave absolutely no survivors (works best when the resistant gene is dominant and the target population is small and isolated).1-C, 2-A, 3-B1-A, 2-C, 3-B1-B, 2-A, 3-C1-C, 2-B, 3-A Question 14: Match each ectoparasite species with its known insecticide resistance profile according to the text:Column I:1. Psoroptes ovis2. Rhipicephalus sanguineus group3. Bovicola ovis4. Lucilia sppColumn II:A. Resistance reported to amitraz, dichlorfenvinphos, and cypermethrin.B. Resistance reported to gamma-hexachlorohexane, diazinon, propetamphos, flumethrin, and high-cis-cypermethrin.C. In Australia: resistance reported to dieldrin, diazinon, and diflubenzuron.D. Resistance reported to aldrin, dieldrin, gamma-hexachlorohexane, diazinon, deltamethrin, and high-cis-cypermethrin.1-B, 2-A, 3-D, 4-C1-A, 2-B, 3-C, 4-D1-B, 2-C, 3-A, 4-D1-D, 2-A, 3-B, 4-C Question 15: Consider the following statements regarding amprolium and its combinations:I. Amprolium acts on first-generation meronts, preventing merozoite differentiation.II. In rabbits, amprolium is highly effective against both intestinal and hepatic coccidiosis.III. Amprolium is combined with ethopabate, sulphaquinoxaline, and pyrimethamine to improve efficacy against amprolium-resistant Eimeria.IV. Its safety margin is high due to the higher thiamine requirement of rapidly dividing coccidian cells compared to host cells.Which of the statements are correct?I, III, and IV onlyI, II, and IV onlyII and III onlyI, II, III, and IV Question 16: Consider the following non-chemical approaches to reduce reliance on anthelmintics in sheep:I. Breeding sheep that are genetically resistant or tolerant to worm infections.II. Feeding nematophagous fungi to trap larvae in the faeces.III. Dietary supplementation with rumen bypass protein or condensed tannin-rich forages.IV. Periodic grazing of pastures containing forage species with anthelmintic properties.Which of these approaches are recommended according to the text?I, II, and III onlyII, III, and IV onlyI, III, and IV onlyI, II, III, and IV Question 17: Consider the following statements about phenanthridines and their administration:I. Intramuscular injection of isometamidium in horses and camels is preferred to avoid local reaction.II. Deep intramuscular injection of homidium salts effectively reduces local irritation at the injection site in cattle.III. Intravenous injection of isometamidium in horses and camels may cause systemic toxicity (salivation, tachycardia, collapse) due to histamine release.IV. Homidium salts are highly effective against T. c. congolense but show very limited efficacy against T. v. vivax in cattle.Which of the statements are correct?II and III onlyI, II, and III onlyI and IV onlyII, III, and IV only Question 18: Assertion (A): Polyether ionophore compounds such as monensin, salinomycin, and narasin should never be administered to horses.Reason (R): These ionophores are extremely toxic to horses.Both A and R are true, and R is the correct explanation of A.Both A and R are true, but R is not the correct explanation of A.A is true, but R is false.A is false, but R is true. Question 19: Assertion (A): The developmental stages of Eimeria affected by diclazuril vary depending on the Eimeria species being targeted.Reason (R): Diclazuril is highly effective against all stages of Eimeria tenella, but is only active against the gamont stages of Eimeria maxima.Both A and R are true, and R is the correct explanation of A.Both A and R are true, but R is not the correct explanation of A.A is true, but R is false.A is false, but R is true. Question 20: A parasitologist is using the McMaster quantitative technique to count nematode eggs in a sheep's faecal sample. They weigh 3.0 g of faeces, break it up in 42 ml of water, sieve it, and perform the steps as described in the protocol. If they count a total of 12 eggs under the etched areas of both chambers of a standard McMaster slide, what is the calculated number of eggs per gram (epg) of faeces?120 epg600 epg1,200 epg2,400 epg
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