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Do Female Hamsters Menstruate?

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Once a female hamster reaches the age of reproductive maturity, she becomes fully capable of mating and carrying young. Although mature female hamsters do not menstruate, they do go into "heat" or "estrus" cycles every several days. If you notice your pet bleeding, a veterinary appointment is definitely in order.

White Discharge

Although female hamsters do not menstruate as certain other animals do, they do emit a noticeable vaginal discharge during their heat cycles. The discharge, however, is nothing like menstrual blood. Instead, it is white and fibrous in appearance, according to the University of Cincinnati Environmental Health & Safety division. The discharge may also possess a marked odor, as well.


A hamster's typical heat cycle lasts for around four days or so, reports the Louisiana Veterinary Medical Association. Before estrus begins, a hamster may experience some totally clear and unsubstantial vaginal discharge. Once heat is on the verge of completion, she may have a thicker and denser-looking discharge. If a hamster lacks this second wave of discharge, it may be a sign that pregnancy has occurred, so take note.


If your female hammie becomes pregnant, you can expect it to last for roughly 16 days -- very brief compared with many other animal species. Hamster litters usually consist of between five and nine youngsters, although they can be both smaller and larger, as well. Newborn hamsters are incapable of seeing and hearing, and are completely devoid of fur. The typical weight range of a newborn usually is 2 to 3 grams.

Veterinary Attention

If you observe any vaginal bleeding in your hamster, cross "menstruation" off the list of possible reasons. Vaginal bleeding in hamsters may be a sign of a medical condition, so schedule an appointment for your pet as soon as possible. The bleeding may be a symptom of ovarian cysts, or in pregnant hamsters, dystocia. Do not wait around to see the vet -- time is of the essence. Procrastinating about taking your hammie to the vet may only exacerbate the possible condition, so take the matter seriously and be prompt.