Determining whether or not a dog is pregnant can be a surprisingly difficult task. Many of the hormonal changes that are traditionally associated with pregnancy occur after a female dog has been in heat regardless of whether or not she is pregnant. Therefore, some of the physical and behavioral changes that are seen with pregnancy occur even when an individual is not pregnant. This is called a false pregnancy.
X-rays are the traditional method of confirming pregnancy in dogs, but they do not provide definitive results until 39-50 days after mating. An ultrasound can be used earlier, but veterinarians must be specially trained if they are to be effective ultrasonographers, and the machines are not available at every veterinary clinic.
Thankfully, a quick and easy canine pregnancy test is now available that can be used 22 to 27 days after mating and provides reliable results. It measures blood levels of the hormone relaxin, which starts to rise after a fertilized egg has implanted in a dog’s uterus. Only a small blood sample is required to run the test. The canine pregnancy test kit can be used to diagnose a planned or unplanned pregnancy, rule out a false pregnancy, and to determine whether a pregnancy has been terminated.