Whether you’ve bred your female cat on purpose, or if she’s had an "accidental" encounter with a neighboring tomcat, you might be wondering if your cat is pregnant. Are there over the counter hormone testing kits, like the ones humans use, to determine whether your can may be pregnant?
They aren't, but your vet can prescribe a kit you can use at home, or with your vet's help.
Hormone Test Kits
When cats are pregnant, a hormone called relaxin is present in the bloodstream at about 20 to 25 days after insemination. Relaxin is pregnancy specific, meaning that if it is found in the blood, your cat is definitely expecting.
As such, there are relaxin assays that your vet can prescribe for home use. However, using the test can be tricky. To use an at-home cat pregnancy test, you must first draw your cat’s blood. This can be impediment enough for some pet owners, but it doesn’t stop there. After drawing the blood, it then has to be "processed" before the kit can be used to determine pregnancy. The blood will need to be transferred into a centrifuge to isolate the plasma.
All this can be learned, and many professional breeders undertake the challenge. Centrifuges can be purchased -- they’re not all that expensive -- and you can learn to draw your cat’s blood yourself. If this is something you’ll be doing a lot as a breeder, it may make financial and logistical sense.
For your average pet parent, a trip to the veterinarian is probably the easiest way to determine pregnancy.
Other Options for Determining Pregnancy
If home pregnancy testing sounds like more than you want to undertake, there are other options to determine whether your cat may be pregnant.
First, you can wait until your cat is “showing.” At 3 or 4 weeks of gestation, your cat’s belly will be swollen enough to make a diagnosis of pregnancy pretty easily. Also, just prior to this period, her nipples will swell and turn pink—an unmistakable sign. Remember, vet visits are recommended at the beginning of the pregnancy. So once you suspect, head to the vet.
Your vet can take an ultrasound to visualize the presence of fetal kittens at about 3 1/2 weeks. At 24 days, the fetal heartbeat can be heard. Your vet can also palpate your cat’s abdomen to feel for the presence of kitten embryos.