Hamster Losing Or Pulling Out His Fur

What would cause an otherwise healthy hamster to lose the fur on his belly, part of his back and leg?

If a hamster does not feel comfortable in his environment, he may start barbering his fur. Via Su--May/Flickr

By Karen Rosenthal, DVM, MS


My daughter’s hamster seems to be losing or eating his fur. It seems that his whole underside / belly is bare, and now he’s working on areas on his back. One of his legs looks like he’s been working on it as well. Any ideas as to what might cause this? My daughter cleans his cage once a week. He seems to be drinking and eating fine. He’s active, especially at night. He does not seem to be sick in any way other than the lack of fur on his belly and spots on his back. 


If your hamster is removing his hair, that is termed “barbering.” Hamsters and other animals will do this for a variety of reasons and, sadly, there are many times that we run all of the diagnostic tests we have available and still cannot figure out why an animal barbers itself.

It is very important, and sometimes very difficult, to determine if the hair is just falling out or if your hamster is truly chewing or pulling his hair out. The reason this is so important is that we have different diagnostic and treatment pathways based on this discriminator — is the hair coming out on its own or is your hamster pulling it out.

If the hair is being pulled out, the two major categories for this include physical reasons and psychological reasons. Physical reasons include parasites, bacterial infections, environmental skin irritants and organic disease. These are all reasons that a hamster may feel skin discomfort and chewing out the hair is one way for the hamster to relieve that discomfort. Psychological reasons include dominance by another hamster leading to displacement behavior of pulling out the hair. If your hamster feels “unsafe” in his enclosure or for whatever reason feels “uneasy” in his enclosure or surroundings, he may pull his hair out.

How can we tell exactly what is going on? An examination of the hair and skin can sometimes lead us to an answer. A description of the environment and history is also helpful. Finally, depending on the cause, treatment may include medications or improvements to the husbandry to help the psychological well-being of your hamster.

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Article Categories:
Critters · Hamsters