The clinical and pathological features of an outbreak of parvovirus infection are described. In young puppies these were vomiting, diarrhoea and myocarditis whereas in older animals they were weight loss and enteropathy. Other features seen were interstitial pneumonia, lymphoid depletion and, in one dog, renal tubular degeneration. The haematological picture was inconsistent, a reduced number of circulating neutrophils or lymphocytes occurring in some cases whereas in others neutrophilia or lymphocytosis was present.