Sarcocystosis in cattle in Kentucky

Area of Science:

• Veterinary Parasitology
• Bovine Medicine
• Food Animal Health

Background:

• Sarcocystosis is a parasitic disease affecting livestock, caused by protozoa of the genus Sarcocystis.
• Sarcocystis bovicanis is a significant pathogen in cattle, potentially leading to severe clinical manifestations and economic losses.

Observation:

• Forty-one eighteen-month-old cattle (heifers and steers) presented with anorexia, severe weight loss, nervousness, hypersalivation, lameness, and characteristic "rat-tail" appearance due to hair loss.
• Necropsy revealed generalized lymphadenopathy, oral and esophageal erosions/ulcerations, severe laminitis, and microscopic evidence of young Sarcocystis sp. cysts in cardiac, skeletal muscle, and brain tissues.
• Histopathology showed nonsuppurative myocarditis and myositis with myofiber degeneration and inflammatory cell infiltration.

Findings:

• Ultrastructural analysis confirmed the presence of young Sarcocystis sp. cysts containing metrocytes.
• Indirect hemagglutination tests showed a high mean antibody titer (1:24,000) against Sarcocystis bovicanis antigen in affected cattle.
• Epidemiological investigation implicated farm dogs housed in a hayloft as the infection source, with hay contaminated by dog feces suspected as the transmission route.

Implications:

• This study highlights the critical role of canine hosts in the Sarcocystis bovicanis life cycle and transmission to cattle.
• Effective parasite control strategies should focus on managing canine populations and preventing fecal contamination of animal feed.
• Understanding the transmission dynamics is crucial for preventing outbreaks and mitigating economic impacts of sarcocystosis in beef cattle production.