Peer-reviewed veterinary case report
Adult dog died from widespread neosporosis after prednisone treatment
By Rodriguez, Constanza L et al.·Published in Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc·2026·School of Veterinary Medicine·View original on PubMed →
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Original publication title: Seronegative disseminated neosporosis with fatal outcome in an adult dog following prednisone therapy.
- Species:
- dog
Plain-English summary
A 4-year-old male English Mastiff was brought in after showing signs of weakness in all four legs, difficulty walking, and severe muscle wasting. Unfortunately, despite treatment, the dog's condition worsened, leading to euthanasia. An autopsy revealed widespread muscle damage and signs of a protozoal infection called neosporosis, which can affect the muscles and nervous system. This case shows that even if blood tests for neosporosis come back negative, it can still be present, especially in dogs receiving steroid treatments like prednisone.
People also search for: dog muscle wasting · English Mastiff weakness · neosporosis treatment in dogs · prednisone side effects in dogs
Abstract
A 4-y-old, male English Mastiff with a history of inflammatory neuromuscular disease developed progressive tetraparesis, ataxia, and severe temporal muscle atrophy, culminating in non-ambulatory status and euthanasia. The autopsy revealed diffuse muscle atrophy and pale pulmonary nodules. Histologically, polyphasic myositis was evident, with apicomplexan organisms within skeletal muscle myofibers. Encephalomyelitis, myocarditis, and hepatitis with protozoal cysts and tachyzoites also were observed. Immunohistochemistry of brain tissue was strongly positive forand, but PCR testing confirmedand excluded, establishing a diagnosis of disseminated neosporosis. Despite extensive tissue involvement,antibody titers were below the diagnostic cutoff. Our case highlights that non-positive serologic results do not exclude neosporosis in clinically compatible cases, particularly in dogs undergoing corticoid therapy, and underscores the diagnostic value of histopathology with confirmatory molecular testing for definitive diagnosis.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41612780/