CASE 13. Infertility in a queen
Case Information: You are presented with a 2 year old intact female Maine Coon for the complaint of infertility. Her history is that she is housed with an intact male that has impregnated other queens. The owner of the cat has seen the cat showing signs of heat, including lordosis and monotonous yowling, about every three weeks for months. She leaves the female with the male while she is at work and assumes they are breeding because the queen goes out of heat after about 7 days.
Question:
What are some possible causes for infertility in this queen?
Answer:
Remember that queens are induced ovulators and that it takes more than one copulation, on average, to induce ovulation. This owner should be observing the cats to make sure mating is taking place and should try to achieve four copulations between this queen and the chosen tom during estrus.
Question:
Do you have any evidence that ovulation is not occurring? How can you diagnose this definitively?
Answer:
The fact that the queen continues to cycle about every 3 weeks suggests she
is never induced to ovulate. Queens that are induced to ovulate but do not become
pregnant maintain luteal tissue and do not go back into estrus for about 45
days. Definitive diagnosis requires drawing of blood from this queen when the
owner perceives her to be going out of heat; if serum progesterone concentration
is less than 2 ng/ml, she was not induced to ovulate.