EVA abortions in horses show fetuses that are which autolysis pattern relative to EHV abortions?

• A. Greatly autolysed
• B. Freshly aborted with edema and minimal autolysis
• C. No autolysis
• D. Moderate autolysis

Answer: (A)

Autolysis pattern in aborted fetuses can help distinguish viral causes in horses. Equine arteritis virus (EVA) abortions typically produce fetuses that are greatly autolysed. This reflects rapid fetal death followed by extensive endogenous enzyme digestion, so tissues show significant breakdown by the time they’re examined. In contrast, EHV abortions more often yield fresher fetuses with edema and only minimal autolysis, because the fetal death occurs in a way that leaves tissues less degraded at necropsy. So the most characteristic finding for EVA abortions relative to EHV abortions is a fetus that is greatly autolysed.