– We bred her several times Doc. She had this one litter a couple of years ago but since then, nothing… We used different males, we are sure they are fertile since they bred again after and did not miss any other female. To tell you the truth, we are a bit desperate. She is such a valuable breeding subject.
When I worked at the veterinary school in France, this would be a conversation I would have on a regular basis. Probably several times a week. Let’s be fair : that’s what you would expect in a department focusing on assisted reproduction and fertility. There was however a tiny little difference on this Monday afternoon. At that time, our clients were mainly dog breeders. On this day however, it was a cat breeder I was talking to.
I remember when I first mentioned this case I was working one to some of my veterinary friends. They had a hard time believing it. « Come on, infertility consultations… in cats ?!?!? No way ! If it does not work in this species, it is simply not meant to be. » I was not really surprised by their reaction. I certainly felt the same way when I was a younger veterinarian. I had seen the figures showing us how prolific cats could be. I had seen it in real life too, coming from a tropical island. I used to think that in this species, infertility rhymed with sterility. The only solution I would offer back in the days : spaying. I learnt quite a lot since.
When I started my residency, I read all there was on infertility in felines. I found out that it might not be as uncommon as I thought.
Number 1 cause : lack or insufficient amount of breeding (see here for more info). Cats are induced ovulators : not enough stimulation = no ovulation. This case however seemed a bit different. The breeder told me she observed all the breedings. She described to me the normal behavioural signs that need to be observed to make sure it indeed occurred. I knew it was not enough to fully exclude this hypothesis, but still… In my mind it made it less likely.
One might think here : what about infectious diseases ? In cat breeding, I indeed constantly repeat this is something we should always keep in mind. However, there is one thing I was definitely sure of : long is the list… And while we were in the consultation room discussing the case, there was another diagnostic step I was considering prior to that : looking at the queen’s uterus and her ovaries. Performing genital ultrasounds seemed to me kind of mandatory.
It makes total sense : you first want to make sure everything looks normal on the genital tract. In humans, they use ultrasounds in the infertility diagnostic work-up all the time. In my opinion, the same should apply to dogs and cats.
The owner agreed. We did the ultrasounds… We found this.