BCSE Theriogenology and Veterinary Reproduction 1 — Questions and Answers
Question 1: In the bitch, serum progesterone concentrations above 5 ng/mL typically indicate which reproductive event?
- Proestrus onset
- LH surge
- Ovulation has occurred (Correct answer)
- Anestrus
Correct answer: Ovulation has occurred
Progesterone rises above 5 ng/mL after ovulation in the bitch, confirming that ovulation has already taken place.
Question 2: Which stage of the canine estrous cycle is characterized by vaginal cornification >80% and a marked decrease in neutrophils on cytology?
- Proestrus
- Estrus (Correct answer)
- Diestrus
- Anestrus
Correct answer: Estrus
During estrus, vaginal cytology shows >80% cornified squamous cells and absence of neutrophils, reflecting peak estrogen influence.
Question 3: In cattle, the corpus luteum (CL) can be lysed using exogenous prostaglandin F2α (PGF2α) between which days of the estrous cycle?
- Days 1–4
- Days 5–16 (Correct answer)
- Days 17–20
- Days 1–20
Correct answer: Days 5–16
PGF2α is effective at lysing the CL only from approximately days 5–16 of the bovine estrous cycle when the CL is mature and responsive.
Question 4: What is the average gestation length of the mare?
- 270–280 days
- 300–340 days
- 335–345 days (Correct answer)
- 360–380 days
Correct answer: 335–345 days
The average gestation length in mares is approximately 335–345 days, with normal ranges from 320 to 360 days.
Question 5: Which feline reproductive characteristic distinguishes cats from dogs in terms of ovulation?
- Cats are spontaneous ovulators
- Cats require mating or cervical stimulation to ovulate (induced ovulation) (Correct answer)
- Cats ovulate only once per year
- Cats have a 21-day estrous cycle like cattle
Correct answer: Cats require mating or cervical stimulation to ovulate (induced ovulation)
Cats are induced ovulators, requiring coital or mechanical cervical stimulation to trigger the LH surge and subsequent ovulation.
Question 6: A cow presents with a soft, fluid-filled uterus and bilateral enlarged uterine horns at 4 weeks post-calving. The most likely diagnosis is:
- Hydrometra
- Pyometra (Correct answer)
- Mummified fetus
- Mucometra
Correct answer: Pyometra
Bovine pyometra post-calving presents as a distended uterus filled with purulent fluid, often associated with a retained CL and bacterial infection.
Question 7: In equine reproduction, the hormone primarily responsible for maternal recognition of pregnancy and CL maintenance is:
- Estrogen
- Progesterone from accessory CLs
- Equine chorionic gonadotropin (eCG) (Correct answer)
- Oxytocin
Correct answer: Equine chorionic gonadotropin (eCG)
eCG (formerly PMSG), produced by endometrial cups from days 40–150, stimulates formation of accessory CLs that maintain progesterone levels during early equine pregnancy.
BCSE Theriogenology and Veterinary Reproduction 1
In the bitch, serum progesterone concentrations above 5 ng/mL typically indicate which reproductive event?