Polymerase chain reaction analysis for viruses in paraffin-embedded myocardium from dogs with dilated cardiomyopathy or myocarditis

Objective-To perform polymerase chain reaction (PCR) analysis on paraffin-e mbedded myocardium from dogs with dilated cardiomyopathy (DCM) and dogs wit h myocarditis to screen for canine parvovirus, adenovirus types 1 and 2, an d herpesvirus, Sample Population-Myocardial specimens from 18 dogs with an antemortem diag nosis of DCM and 9 dogs with a histopathologic diagnosis of myocarditis wer e evaluated. Procedure-Paraifin-embedded myocardial specimens were screened for viral ge nome by PCR analysis. Positive-control specimens were developed from cell c ultures as well as paraffin-embedded tissue specimens from dogs with clinic al and histopathologic diagnoses of viral infection with canine parvovirus, adenovirus types 1 and 2, and herpesvirus. The histologic characteristics of ail myocardial specimens were classified regarding extent, location, and type of inflammation and fibrosis. Results-Canine adenovirus type 1 was amplified from 1 specimen from a dog w ith DCM. Canine parvovirus, adenovirus type 2, and herpesvirus were not amp lified from any myocardial specimens. Histologic analysis of specimens from dogs with DCM revealed variable amounts of fibrosis; myocardial inflammati on was observed in 1 affected dog. Histopathologic analysis of specimens fr om dogs with myocarditis disclosed variable degrees of inflammation and fib rosis. Conclusions and Clinical Relevance-Viral agents canine parvovirus, adenovir us types 1 and 2, and herpesvinrs are not commonly associated with DCM or a ctive myocarditis in dogs. Additional studies evaluating for nucleic acid f rom viruses that less commonly affect dogs or different types of infectious agents may be warranted to gain insight into the cause of DCM and myocardi tis in dogs.