NEOPLASMS IN FERRETS

Ferrets have become accepted as household pets.  Consequently, many veterinarians have examined and treated ferrets in their practices, and the veterinary community has improved its knowl­edge of the various diseases affecting ferrets.

In reviewing ADDL records and the veterinary literature  , it is apparent that ferrets are susceptible to a variety of neo-plastic diseases.  Probably the 5 most common neoplasms that occur in ferrets are (in alphabetical order): adrenal cortical tumors, chordomas,lymphoid tumors, mast cell tumors, and pan­creatic islet cell tumors.

Adrenal cortical tumors are usually malignant (adrenal corti­cal carcinomas).  Clinical signs may be related to local tumor growth, such as infiltration of blood vessels resulting in hem­orrhage, to excessive steroid hormone production, or nonspecifi-cally to malignant disease.  Ferrets with hypercortisolism sec­ondary to functional adrenal cortical carcinomas may present with cachexia,alopecia,polydipsia, and lymphopenia; one ferret had concurrent adenomatous mammary gland hyperplasia.

Chordomas are unusual neoplasms of the axial skeleton, thought to arise from embryonic notochord.  Their histology is similar to that of chondrosarcomas.  In ferrets, most chordomas develop at the tip of the tail and therefore are easily removed.  In humans and rats however, chordomas are locally invasive and may metastasize, so they have a potential for aggressive clinical behavior.

Lymphoid tumors reported in ferrets include lymphoma(lympho-sarcoma),lymphocyticleukemia, and plasma cell myeloma.  In some cases, the lymphoma appeared to have arisen in the spleen. The myeloma was primary in a lumbar vertebra and had caused a pathologic fracture with subseguent spinal cord compression and paraplegia.

Mast cell tumors (mastocytomas) occur in the skin of ferrets. These tumors do not appear to have a predilection for any par­ticular location.  Although ferrets with multiple cutaneous mast cell tumors have been reported, none have had visceral tumors or were thought to have died as result of their mast cell tumor(s).

Pancreatic islet cell tumors in ferrets usually arise from beta cells and produce insulin (insulinomas).  Ferrets with in-sulinomas may present with signs of hypoglycemia, such as weak­ness and seizures, as a result of high serum insulin concentra­tions.  Some ferrets have posterior paresis, tentatively at­tributed to a secondary peripheral neuropathy.  Malignant insu­linomas have metastasized to the liver and spleen.

Dr. E.B.Janovitz, Diagnostic Pathologist

If you would like a copy of the references used for this ar­ticle, please write: Rebecca Gwin, Animal Disease Diagnostic Laboratory, Purdue University, W. Lafayette, IN 47907-1175 or call (317) 494-7448.