CLUSTERS OF LYMPHOMA IN FERRETS

Cluster outbreaks of lymphoma and leukemia have been associated with v iral infections in many species including humans, cattle, and cats. Th is study describes epidemiological, clinical, and pathological feature s of cluster outbreaks of lymphoma in multiferret households and exami nes and compares the Aleutian disease virus (ADV) and feline leukemia virus (FeLV) status of cases, ferrets at risk, and controls. Three fer ret groups with 21 cases of histologically diagnosed lymphoma (12.6% c umulative incidence) and their cohabitants (n = 35) were examined and compared with three control groups (n = 52) of cohabitating ferrets wi thout lymphoma. A familial distribution was observed in one group but most cases were not consanguinous. Ferrets greater than 3 years of age developed chronic disease in two of the groups and 2-year-old adults had acute disease in the remaining group. Lymphocytosis, splenomegaly, and lymphadenopathy were prominent features. Histologically, predomin antly small noncleaved cell and polymorphous lymphoid lesions were obs erved. All of the ferrets with lymphoma that were tested for ADV and F eLV using serology or PCR were negative. The rate of ADV antibody amon g cases or ferrets at risk was not significantly different from contro ls. None of the cluster ferrets were seropositive for FeLV p27 antigen using a monoclonal ELISA. Infection with a novel ferret virus is susp ected, but an etiological agent has not yet been identified.