Lymphocytic myenteric ganglionitis associated with equine herpesvirus infection: A cause of chronic intestinal pseudo‐obstruction and recurrent colic in an adult horse.

Summary: This report describes a rare case of chronic intestinal pseudo‐obstruction (CIPO) in a 12‐year‐old Quarter Horse gelding, caused by lymphocytic myenteric ganglionitis (MG) associated with equine herpesvirus 1 (EHV‐1) and equine herpesvirus 5 (EHV‐5) infection. The horse presented with recurrent colic and weight loss over 1.5 years. Repetitive transrectal examinations consistently revealed small colon impaction and enlargement. During postmortem examination alternating segments of enlarged and reduced luminal diameter were observed throughout the entire intestinal tract. MG with lymphocytic infiltrates and neuronal degeneration of the large intestine were found on histopathological analysis. Additionally, polymerase chain reaction (PCR) analysis confirmed the presence of EHV‐1 and EHV‐5 DNA in affected intestinal tissues. Further research is needed to understand the pathophysiology of MG and its association with herpesviruses. Early recognition and diagnosis of MG‐associated CIPO may improve treatment approaches and outcomes for future cases. [ABSTRACT FROM AUTHOR]