ENADE: Medicina Veterinária · Brazil · INEP
Original practice questions written to the published syllabus · not past papersInnate and adaptive immunity, antibodies and complement, hypersensitivity, vaccines and the cold chain, and the serological tests used in diagnosis and surveillance.
In the exams: ICAR AICE-JRF core group 06; ICAR AIEEA-PG 13 (Microbiology); NAVLE health maintenance and prevention 35%
How our questions for ENADE spread across the units of Veterinary Immunology & Serology. Difficulty: 14 easy, 27 medium, 4 hard.
| Serological tests: ELISA and agglutination | 6 | |
| Hypersensitivity | 4 | |
| Serological tests: CFT, AGID and virus neutralisation | 4 | |
| Colostral immunity | 4 | |
| Immunopathology | 4 | |
| Adaptive immunity | 3 | |
| Immunoglobulins | 3 | |
| Vaccine types | 3 | |
| Adjuvants | 3 | |
| The vaccine cold chain | 3 | |
| Innate immunity | 2 | |
| Antigens and antibodies | 2 | |
| Complement | 2 | |
| The major histocompatibility complex | 2 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
A 3-year-old dairy cow has acute toxic mastitis. Which acute phase protein is most useful as a sensitive inflammatory marker in this species?
C. Haptoglobin
In cattle haptoglobin and serum amyloid A are the major acute phase proteins, rising many-fold. C-reactive protein is the major one in dogs and pigs, not cattle; α1-acid glycoprotein is a marker in cats; albumin is a negative acute phase protein and falls.
Further reading: Tizard IR, Veterinary Immunology, 10th ed.
Which transcription factor identifies regulatory T cells?
D. FoxP3
FoxP3 defines regulatory T cells. T-bet drives Th1, GATA-3 Th2 and RORγt Th17 differentiation; students often confuse the lineage-defining factors.
Further reading: Tizard IR, Veterinary Immunology, 10th ed.
The overall binding strength of a multivalent antibody to a multivalent antigen is called:
A. Avidity
Avidity is the total strength of multivalent binding; affinity is the strength of a single binding site for a single epitope. Pentameric IgM has modest affinity but high avidity.
Further reading: Tizard IR, Veterinary Immunology, 10th ed.
Purpura haemorrhagica in horses following Streptococcus equi infection is classified as a:
A. Type III (immune complex) hypersensitivity
Purpura haemorrhagica is an immune-complex vasculitis involving streptococcal M protein and antibody deposited in vessel walls. It is not IgE-mediated and not primarily an antiplatelet reaction.
Further reading: Tizard IR, Veterinary Immunology, 10th ed.
A dairy herd uses the comparative cervical tuberculin test. An animal shows a larger reaction at the avian PPD site than at the bovine site. The most defensible interpretation is:
C. Sensitisation by non-tuberculous mycobacteria or M. avium subsp. paratuberculosis is more likely than M. bovis infection; national rules set the exact classification
The comparative test separates M. bovis infection (bovine reaction exceeds avian) from sensitisation by other mycobacteria (avian exceeds bovine). The thresholds are set nationally. The test is type IV and is read at about 72 hours.
Further reading: WOAH Manual of Diagnostic Tests and Vaccines for Terrestrial Animals
In a vaccine trial, the attack rate was 40% in unvaccinated calves and 8% in vaccinated calves. Vaccine efficacy is:
A. 80%
Efficacy = (ARU − ARV) ÷ ARU = (0.40 − 0.08) ÷ 0.40 = 0.80 = 80%. 32% is the absolute difference in percentage points, not efficacy; 20% is ARV ÷ ARU; '5-fold' is the relative risk inverted, not efficacy.
Further reading: Thrusfield M et al., Veterinary Epidemiology, 4th ed.
Why should ice packs be 'conditioned' before packing freeze-sensitive vaccines in a cold box?
C. Packs straight from the freezer are well below 0 °C and can freeze vaccine touching them
Conditioning means leaving frozen packs until the ice begins to melt and moves inside, so the pack is near 0 °C and will not freeze vaccines. It warms rather than cools the pack slightly.
Further reading: WHO guidance on vaccine temperature sensitivity and the Shake Test
A CFT result is reported as 'anticomplementary'. This means:
B. The serum destroyed complement even without antigen, so it cannot be read
Anticomplementary sera (contamination, haemolysis, immune complexes, poor storage) consume complement in the control well without antigen, so neither positive nor negative can be concluded; a fresh sample or another test is needed.
Further reading: WOAH Manual of Diagnostic Tests and Vaccines for Terrestrial Animals
Puppies receive a series of core vaccine doses every 2–4 weeks until about 16 weeks of age or older mainly because:
A. Maternal antibody blocks vaccination and wanes at an unpredictable age in each puppy
Maternal antibody neutralises vaccine virus while present; the age it falls below interfering levels varies between puppies, so repeated doses ensure one is given soon after it wanes. Puppies can make IgG much earlier.
Further reading: WSAVA Guidelines for the vaccination of dogs and cats, 2024
Bovine leucocyte adhesion deficiency (BLAD) in Holstein cattle is due to a defect in:
C. CD18 (β2 integrin)
The CD18 defect stops neutrophils adhering to endothelium and leaving blood, so calves show persistent marked neutrophilia yet recurrent infections.
Further reading: Tizard IR, Veterinary Immunology, 10th ed.
Ten here, 45 in the app. The Laisha app has every practice question we have written to ENADE 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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