Peer-reviewed veterinary case report
Hepatic sarcocystosis in a horse.
- Journal:
- The Journal of parasitology
- Year:
- 1999
- Authors:
- Davis, C R et al.
- Affiliation:
- Department of Anatomy · United States
- Species:
- horse
Plain-English summary
A horse was diagnosed with a condition called hepatic sarcocystosis, which is an infection affecting the liver. This horse also had serious issues like a stubborn bone infection and a tumor in the jaw, along with liver problems caused by salmonella bacteria. The horse showed signs of fluid buildup in various body cavities, an enlarged liver, stomach ulcers, and swelling in the colon. Under a microscope, the liver showed severe damage and the presence of protozoa (tiny organisms) that were developing in the liver cells. This case is notable because it is the first time this type of liver infection has been reported in horses, but the exact source of the infection and how it spreads are still unknown.
Abstract
Hepatic sarcocystosis was diagnosed in a horse in association with refractory bacterial osteomyelitis and plasma cell tumor of the maxilla and hepatic salmonellosis. Gross lesions included pleural, pericardial, and peritoneal effusions, hepatomegaly, gastric ulceration, colonic edema, and proliferative tissues filling 2 maxillary dental alveoli. Histologically, liver was characterized by severe suppurative, necrotizing, periportal hepatitis, and severe periacinar necrosis. Hepatocytes frequently contained protozoal schizonts in various stages of development. In mature schizonts, merozoites were often arranged radially around a central residual body, consistent with asexual division by endopolygeny. Ultrastructural features of merozoites included an apical conoid and polar ring, anterior micronemes, central nuclei, and absence of rhoptries. These protozoa did not react to antisera raised against Neospora caninum, Sarcocystis neurona, Toxoplasma gondii, or Hammondia hammondi. The microscopic and ultrastructural characteristics and immunoreactivity of this organism are consistent with a Sarcocystis sp. other than S. neurona. This is the first report of Sarcocystis-associated hepatitis in a horse. The life cycle of this organism and source of infection are unknown.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/10577737/