A clustering of generalized malignant lymphoma is reported in a single
household of Rottweiler dogs (both parents and three of the four sibl
ing in one litter) and in a breeding pair of unrelated Scottish terrie
rs. In addition, malignant lymphoma of the myocardium was found in thr
ee directly related otterhounds (the sire and two Sibling offspring).
Possible genetic and viral factors in the aetiology of canine malignan
t lymphoma are discussed.