Epizootic of viral enteritis in dogs in Thailand

An epizootic of enteritis occurred in dogs in Thailand during 1979. Observations were made on 44 dogs that had clinical signs of enteritis or had a recent history compatible with a clinical diagnosis of enteritis. Eight of the 44 dogs died. Gross and histopathologic examinations performed on these dogs revealed that the lesions were similar to those described for canine viral enteritis. Antigens that agglutinated rhesus macaque RBC were detected in feces from 4 of 20 dogs. Cytopathic effects were observed in canine A-72 cells after their inoculation with fecal suspensions from these 4 dogs and with a fecal suspension from another dog. Cell cultures inoculated with each of the suspensions produced antigens that agglutinated RBC. All hemagglutinating antigens were inhibited in the presence of feline panleukopenia virus antiserum. Using electron microscopy, parvovirus-like virions were observed in a fecal suspension from 2 dogs (1 dog that had antigen that agglutinated rhesus macaque RBC and 1 dog that was negative for feline panleukopenia virus). Canine parvovirus hemagglutination inhibition antibody was detected in sera from 33 of the 40 dogs examined, and canine coronavirus (CV) neutralizing antibody was found in 29 of 30 dogs. Antibody titer increases indicative of recent canine panleukopenia virus (CPV)-like virus and CV infections were observed in paired sera for 2 of 35 and for 5 of 30 of the dogs in Thailand were infected with CPV-like virus and a CV, and these viruses were most likely the cause of the epizootic of viral enteritis.