Systemic toxoplasmosis in an adult alpaca

Abstract

An 11-y-old, female alpaca with a history of sternal recumbency for 3 d before death was submitted for autopsy. Hydrothorax, ascites, hepatomegaly, fibrinous pleuritis, cranioventral bronchopneumonia, pulmonary atelectasis, and firm adipose tissue in the thorax and abdomen were observed grossly. Important microscopic findings included chronic lymphocytic and histiocytic hepatitis with necrosis and portal-to-portal bridging fibrosis, thrombosis in thoracic and abdominal adipose tissue, fibrinosuppurative pleuritis, pyogranulomatous pneumonia, and ulcerative gastritis in C1. Intracellular and extracellular clusters of 2-μm basophilic protozoal organisms were observed in liver, thoracic and abdominal adipose tissue, pleura, lungs, and C1. Toxoplasma gondii was detected by real-time PCR in the liver, and tachyzoites within areas of inflammation and necrosis were confirmed by immunohistochemistry. Systemic toxoplasmosis occurs most commonly as an acute disease in neonatal or immunocompromised animals. A predisposing cause was not identified in our case. Although T. gondii seropositivity is common in camelids, clinical disease is extremely rare. Chronic hepatitis is an exceedingly rare lesion of toxoplasmosis. Only one previous report of systemic toxoplasmosis in a South American camelid has been described and involved an adult llama. To our knowledge, fatal toxoplasmosis has not been reported previously in an adult alpaca.