The gestation period greatly varies across species, ranging from the mammoth 480-590 day gestation of the sperm whale, to the more modest 340 equine gestation (I had to mention the horse!), to the relatively minute 21 day gestation of the mouse. The dog has a gestation period of around 61 days, which can be divided into four main stages. It is important for both breeders and veterinarians alike to be familiar with these stages to ensure that the pregnant dog is given the best possible care, and the pregnancy runs smoothly.

Stage one lasts for three weeks, whereby pregnancy is not visually noticeable. In contrast, stage two lasts for two weeks and includes nipple growth, an increase in both food intake and in weight. The pregnancy becomes outwardly visible during stage three of canine pregnancy. Abdominal growth and production of milk occurs, and abdominal movement (by the puppies) may be felt. The final stage can be recognised due to the somewhat restless nature of the expectant mother, and the resultant initiation of nesting, alongside a change in temperature indicative of imminent birth.

Alongside these stages, veterinary ultrasound can be a vital tool during pregnancy. From 28 days post-mating, ultrasound imaging can used to detect and confirm pregnancy, and can aid in the prediction of the resultant litter size. This is important as the more advanced the pregnancy becomes, the more difficult accurate prediction of litter size becomes (Canine Pregnancy Scanning). Ultrasound imaging can also be carried out later in pregnancy where more detailed observations can be made. For example, ‘Canine Scan and Chip’ reveal ultrasound videos at 35 days post-mating and between 49 and 55 days post-mating (YouTube). In the former instance, the opening and closing of the heart valve can be detected, and in the latter the puppy can be seen moving. It should be noted that imaging can be breed-dependent. Additionally, a previously published article describing the use of ultrasound in detecting canine gestational age can be read here.

As is the case with most animal species, veterinary ultrasound has a distance to go before the achievements in human pregnancy can be realised. Nevertheless, the ease of availability of modern technology coupled with our ever expanding knowledge will ensure that canine pregnancy landmarks are better understood. For details on the best ultrasound machines for use in canine pregnancy detection please do not hesitate to contact us.