A cluster of cases of juvenile mediastinal lymphoma in a ferret colony.

Three cases of juvenile mediastinal lymphoma developed in a laboratory colony of ferrets. Two ferrets became acutely moribund, and one was found dead with no preceding signs of illness. Splenomegaly, hepatomegaly, and a large thoracic mass were the primary features in each case. All three ferrets had multiorgan metastasis of the tumor. Two ferrets were tested for feline leukemia virus and Aleutian disease virus with negative results.