Mast cell tumors are commonly seen on the skin surface of ferrets. The mast cell is a histamine-containing element of the immune system, and mast cell tumors are composed of these cells. In other species mast cell tumors can be aggressive and metastasize widely throughout the body, but in ferrets they generally run a benign course, remaining as skin surface nodules. Deaths due to mast cell tumors can occur however, and have been described in the veterinary literature.

Mast cell tumors appear as red skin nodules which are devoid of hair, slightly raised and can be up to ½ inch in diameter (see image). These nodules can be found anywhere on the body, and more than one mass may be present. Because mast cells can release histamines they may be itchy or irritating to the ferret, but this is often not the case.

To definitively treat mast cell tumors, they should be surgically removed. This allows for a microscopic examination by a pathologist to confirm the diagnosis, and removal is usually is curative. Ferrets who have developed mast cell tumors may eventually develop new ones at other sites, in spite of successful surgical excision.

The following picture (.gif) is an example of an animal with a Mast Cell Tumor.

If you have any questions or comments about the information above, feel free to send a message to Dr. Suzanne Lee, D.V.M. at

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