Pregnancy in Dogs
Much like in people, ultrasound is the best way to diagnose pregnancy. It is simple to perform and non-invasive, so there is minimal to no risk for the puppies. It is recommended to wait until four weeks post mating to perform ultrasound to increase the chance of accurate diagnosis. Before this time, foetal heartbeats are not visible so it can be difficult to distinguish pregnancy from normal fluid in the uterus. It is not possible to determine the number of puppies present on ultrasound.
X-ray can be used to confirm pregnancy once the foetal bones start to calcify, around day 42. X-ray can be used to confirm the number of puppies present but has some risk to both mum and babies, so is not recommended for pregnancy diagnosis. X-ray is mostly used during whelping if it is suspected that not all puppies have been delivered.
During the first six weeks of pregnancy, the dog’s energy (calorie) requirements do not change. She should be fed a normal, high quality complete dog food. Weight gain should be minimal, as increasing weight during this early period can cause more difficulties during whelping.
During the last three weeks of pregnancy, the puppies’ growth speeds up. This means they require a lot more energy, and the space for the stomach reduces. At six weeks of gestation the dog should be changed to a high-quality puppy food (over the course of a few days to avoid stomach upset). Puppy food has increased levels of protein and calcium to help support growth. It is also high energy, meaning a lower volume is required to meet requirements. Puppy food should be offered in several small meals, or available all day, with the amount offered increased by roughly 10% each week for the last few weeks of pregnancy. It is still important to avoid the dog putting on excess body fat, so if in doubt check with your vet or nurse.