An 8-year-old spayed female ferret was examined for diffuse generalize
d alopecia, erythema, erosions, crusts, and ulcerated plaques that wer
e nonresponsive to long-term administration of corticosteroids. Cutane
ous epitheliotropic lymphoma was diagnosed on the basis of histologic
examination of skin biopsy specimens. Neoplastic cells were determined
to be of T-lymphocytic origin by results of immunohistochemical stain
ing with a rabbit anti-CD3 monoclonal antibody Additional laboratory a
bnormalities detected included anemia, azotemia, isosthenuria, pyuria,
and bacteriuria. Treatment included isotretinoin and amoxicillin trih
ydrate plus clavulanate potassium administered orally and oatmeal-base
d shampoos. Isotretinoin was tolerated well and cutaneous lesions reso
lved after 60 days of treatment, but pretreatment azotemia worsened an
d the ferret was euthanatized. Necropsy revealed cutaneous epitheliotr
opic lymphoma, pyelonephritis, and interstitial nephritis. Renal disea
se most likely was caused by immunosuppression secondary to chronic tr
eatment with corticosteroids and aging. Isotretinoin, although not cur
ative, may be useful for the palliative treatment of cutaneous epithel
iotropic lymphoma in ferrets.