Gently scruff your hamster (hold it by the loose skin just above the shoulders firmly but without pinching), and turn the animal gently over to check its sex. Males will have prominent testicles just around the tail that make their rumps bulge, whereas females lack this and instead have much more prominent pairs of nipples on the underside. If you’ve always simply assumed that your hamster is female because it had a typically female name when you bought it, then you should probably check. Note that if you think your hamster is pregnant due to a swollen belly, then she’s already to a part of the pregnancy where you should refrain from touching her due to the stress handling causes in the late stages of pregnancy.
This also means you need to be careful storing hamsters from a litter together once they approach six weeks old because they will start mating together. This includes any male hamsters with the mother.
Pyometra, which is a womb infection that distends the hamster’s tummy with pus Enlarged internal organs such as the liver or spleen, which are likely the result of cancer Heart disease, which can lead to the accumulation of fluid in the belly Bowel problems distending the belly with waste due to improper food digestion You may notice other signs of sickness with several of these, including increased thirst (her drinker may empty faster than usual), decreased appetite (note if you’re filling her food bowl less often), and loss of body fat (usually over the ribs).
Note that a hamster likely won’t “show” her pregnancy until the final third of the gestation (day 10+), so you may be less than a week away from her delivering the litter by the time you notice the bump. [4] X Research source Handbook of Rodent and Rabbit Medicine. Laber-Laird. Publisher: Pergamon She will also have enlarged nipples around the same time her belly swells. However, enlarged nipples on a small hamster can be difficult to see, so don’t worry if you can’t spot them beneath the fur. [5] X Research source Handbook of Rodent and Rabbit Medicine. Laber-Laird. Publisher: Pergamon Handling her during the late stage of her pregnancy will upset her, though, so don’t pick her up to look at the nipples.
If the swollen belly lasts longer than 7-10 days without your hamster giving birth (or if she doesn’t exhibit any of the other common behavioral traits for a pregnant hamster in this time), then take her to the vet anyway since she may be presenting symptoms of an illness rather than pregnancy.
Very small quantities of milk and cheese provide calcium for the done development of the litter, and they also help the mother in lactation once the babies are born. [7] X Research source As an additional protein source, you can feed your hamster moderate amounts of hard-boiled egg, nuts, barley, and oats. [8] X Research source Though you must provide them in very small amounts (or risk gastrointestinal problems), pregnant hamsters can benefits from the additional vitamins and minerals found in fruits and vegetables, such as broccoli, cucumber, cauliflower, apples, grapes, bananas, and strawberries. [9] X Research source
Since you may not have any idea when the mother mated, consider that she usually starts “showing” the pregnancy around day ten after mating. [11] X Research source Handbook of Rodent and Rabbit Medicine. Laber-Laird. Publisher: Pergamon
If hamsters kept in the same cage begin fighting despite usually getting along, this is also a sign that one of them may be pregnant if it appears in association with some of the other signs.
This also includes accidentally transferring your scent from other handling of the cage. Don’t try to clean the cage during this period.
