It's generally possible to observe signs of pregnancy in a Boston Terrier approximately 20 days after mating. At this stage, you might notice changes such as enlarged nipples and developing mammary glands. To confirm pregnancy definitively, it's advisable to take your dog for an ultrasound examination at a veterinary clinic around the 30-day mark.
Within about a week post-mating, the female Boston Terrier's vulva may begin to contract, and you might see a small amount of dark brownish discharge, accompanied by a decrease in appetite. Approximately 20 days after mating, signs like erect nipples and mammary gland development become evident. Around the one-month mark, you'll likely see abdominal swelling, sagging mammary glands, elastic nipples, and the mammary glands will become increasingly enlarged, possibly even expressing milk. There will also be a noticeable increase in body weight and the frequency of urination. While these signs usually indicate pregnancy, it’s important to remember that dogs can experience false pregnancies. A definitive confirmation can be achieved by ultrasound, which typically reveals the presence of fetuses around 30 days post-mating. If an ultrasound doesn't show any fetuses within 30 days of observing mammary development, it's likely the dog is not pregnant. During pregnancy, it is crucial to provide your Boston Terrier with appropriate nutrition and a moderate amount of exercise.