Infarctive purpura hemorrhagica in five horses

Abstract

Five horses were examined because of signs of muscle stiffness, colic, or both. All 5 had been exposed to Streptococcus equi within 3 weeks prior to examination or had high serum titers of antibodies against the M protein of S equi. Horses had signs of unrelenting colic-like pain and focal areas of muscle swelling. Four horses were euthanatized. The fifth responded to treatment with penicillin and dexamethasone; after 3 weeks of treatment with dexamethasone, prednisolone was administered for an additional 10 weeks. Common hematologic and serum biochemical abnormalities included neutrophilia with a left shift and toxic changes, hyperproteinemia, hypoalbuminemia, and high serum creatine kinase and aspartate transferase activities. Necropsy revealed extensive infarction of the skeletal musculature, skin, gastrointestinal tract, pancreas, and lungs. Histologic lesions included leukocytoclastic vasculitis in numerous tissues and acute coagulative necrosis resembling infarction. These horses appeared to have a severe form of purpura hemorrhagica resembling Henoch-Schönlein purpura in humans and characterized by infarction of skeletal muscles. Early recognition of focal muscle swelling, abdominal discomfort, neutrophilia, hypoalbuminemia, and high serum creatine kinase activity combined with antimicrobial and corticosteroid treatment may enhance the likelihood of a successful outcome.

Seasonal pasture myopathy in horses in the midwestern United States: 14 cases (1998–2005)

“…Results-Clinical signs occurred during unfavorable weather conditions. Clinical signs of generalized weakness (n = 11 horses), muscle fasciculations (10), lethargy (6), and prolonged recumbency (4) were common. Serum CK activity ranged from 46,487 to 959,499 U/L (reference range, 82 to 449 U/L), and aspartate transaminase activity was > 1,500 U/L (reference range, 162 to 316 U/L).…”

Pathologic Findings in Equine Muscle (Excluding Polysaccharide Storage): A Necropsy Study

“…28 Severe degenerative myopathy in equids can be fatal. 17,19,25,31,32,35 Causes of muscular disorders in adult horses include nutritional myopathy, 5,17,31 infectious disease, 10,17,32,35,38 immune-mediated disorders, 17,25,26 toxic myopathy, 19,36 inherited myopathies, 5,29 endocrinopathy, 2 pasture-associated rhabdomyolysis, 15,44,45 malignant hyperthermia, 1 and exertional rhabdomyolysis. 4,6,23,39 Disorders affecting the peripheral nerves resulting in denervation atrophy of muscle also occur.…”

Haematology and Clinical Biochemistry Findings Associated with Equine Diseases - a Review

“…Hypergammaglobulinemia may be present. A remarkable serum biochemical abnormality is hyperproteinemia (Kaese et al, 2005). Platelet count is usually normal and there is a marked elevated serum activity of creatine kinase and aspartate aminotransferase (Fadok, 1992).…”

“…Infarctive purpura hemorrhagica is an uncommon manifestation of the disease characterized by infarction of tissues of the gastrointestinal tract and muscles, dyspnea and death from blood loss (Kaese et al, 2005).…”

“…The clinicopathological findings associated with infarctive purpura hemorrhagica include elevations in serum activity of creatine kinase (CK) and aspartate aminotransferase, neutrophilia and in severely affected horses, there is evidence of disseminated intravascular coagulation (Kaese et al, 2005).…”