ASRB NET and ARS / SMS / STO Veterinary Protozoology: practice questions

Question 1 · medium

The intermittent fever typical of chronic trypanosomosis is best explained by:

1. Successive waves of parasitaemia from antigenic variation of the variant surface glycoprotein
2. Periodic, synchronised release of merozoites from lymphocytic schizonts in the lymph nodes and spleen
3. Cyclical re-infection from the vector every few days as fresh tsetse flies feed on the animal
4. Synchronous rupture of red cells as in avian malaria

Question 2 · hard

The term 'sanative pair' in trypanosome control refers to:

1. A trypanocide combined with a pour-on acaricide in a single formulation to control both parasite and vector
2. Simultaneous injection of a curative and a prophylactic drug into the same animal on the same day to prevent any relapse
3. Two trypanocides with little cross-resistance, classically diminazene and isometamidium, used alternately
4. The pairing of a trypanotolerant bull with a zebu cow

Question 3 · hard

Endemic stability for bovine babesiosis is most likely to break down when:

1. Calves receive adequate colostrum from immune dams during the first days of life
2. Intensive acaricide use or drought reduces tick challenge so calves escape infection before the age of natural resistance ends
3. Indigenous Bos indicus cattle are kept in the area
4. Tick numbers stay high enough for every calf to be infected in its first months of life, while colostral and age immunity protect it

Question 4 · medium

Why is Theileria annulata of particular economic importance in Indian dairy development?

1. It is transmitted by Culicoides midges and spreads rapidly during the monsoon rains
2. Exotic and crossbred cattle are far more susceptible than indigenous zebu
3. It causes abortion but no deaths
4. It infects only buffalo, which now dominate milk production across India

Question 5 · hard

Toxoplasma oocysts in cat faeces cannot be reliably distinguished by light microscopy from those of:

1. Cryptosporidium parvum
2. Eimeria tenella of chickens
3. Giardia duodenalis cysts
4. Hammondia hammondi

Question 6 · hard

In a herd of 200 cows, 40 are Neospora-seropositive and 8 of these aborted, while 8 of the 160 seronegative cows aborted. What is the relative risk of abortion in seropositive compared with seronegative cows?

1. 2
2. 4
3. 15
4. 0.25

Question 7 · hard

Which immune response pattern is associated with dogs that remain clinically healthy despite Leishmania infantum infection?

1. Complete absence of any immune response
2. A predominantly humoral response with very high antibody titres
3. An IgE-dominated hypersensitivity response
4. A strong Th1-type cell-mediated response with low antibody levels

Question 8 · hard

Treatment with buparvaquone often leaves recovered cattle as Theileria carriers. The most important epidemiological consequence is that:

1. Carriers develop drug resistance in every case
2. Carriers are fully susceptible to reinfection and severe disease on the next tick challenge
3. Carriers transmit infection directly to calves in milk
4. Carriers remain a source of infection for ticks, maintaining transmission in the area

Question 9 · hard

Trypanotolerance, as shown by N'Dama cattle, is best defined as:

1. Resistance to tsetse bites due to thick skin
2. Complete resistance to infection, so that tsetse-borne trypanosomes never establish in the blood
3. Tolerance of high doses of trypanocidal drugs
4. The ability to limit parasitaemia and anaemia and stay productive under trypanosome challenge

Question 10 · medium

The age pattern of clinical anaplasmosis in cattle is:

1. Only neonatal calves infected transplacentally become ill
2. All ages are equally affected
3. Calves are most severely affected, while cattle over two years develop solid, lifelong age resistance to disease
4. Calves under one year are mildly affected, while cattle over two can suffer severe or fatal disease