Sarcocystosis in goats: clinical signs and pathologic and hematologic findings.

Clinical sarcocystosis was studied in 37 goats after inoculation with graded doses of sporocysts of Sarcocystis capracanis. Eight uninoculated goats served as controls. Clinical response varied with the dose. Goats inoculated with 10-40 million sporocysts died between 11 and 13 days after inoculation (DAI), from interstitial pneumonia, vasculitis, and necrosis of mesenteric lymph nodes. All goats inoculated with 100,000 or 1 million sporocysts died between 19 and 23 DAI; clinical signs were anorexia, fever (40-41 C), anemia, and weight loss. Four of 4 goats inoculated with 50,000 sporocysts and 1 of 4 inoculated with 10,000 sporocysts died 24, 28, 39, 68, and 61 DAI, respectively. Goats inoculated with 1,000 sporocysts and uninoculated goats remained clinically normal. After day 18 and before day 68, packed cell volume and hemoglobin content decreased to as low as 11% and 3.6 g/dl, respectively. Alanine aminotransferase and lactic dehydrogenase activities were inconsistently increased. Blood urea nitrogen and bilirubin values were increased, reaching as high as 63 mg/dl and 10 mg/dl, respectively. Histologically, thymic atrophy, vasculitis, hepatitis, cholangitis, myocarditis, generalized myositis, and encephalomyelitis were the main microscopic findings. The cause of the anemia in goats that died after day 19 was not determined.