1976 Volume 1976 Issue 13 Pages 60-78
In 1969, “so-called diarrhea of foals” manifesting fever, colic symptoms, and severe diarrhea and leading animals frequently to death has occurred in the Hidaka district of Hokkaido. Since then, the disease has continued to occur till now, indicating its peak over a period from 1969 to 1971. Forty-four dead animals were examined epizootiologically and pathologically with the following results. The disease occurred in May to November every year. Sixty per cent of the 44 animals died within 3 days. The average interval between the onset of symptoms and death was 6.2 days. Histopathologically, the thread-like elevation of the intima, thromboendarteritis, panarteritis, and aneurysm were mainly found in the anterior mesenteric artery and its related blood vessels. As the other marked changes, verminous granuloma, hemorrhagic and necrotic enteritis due to embolism, and diffuse eosinophilic infiltration were observed. All these changes were caused by the larval migration of Strongylus vulgaris, and led the animals to death. Of the occurrence of this equine disease, few reports have been presented in Japan. Discussion was made on the occurrence and histopathology of the disease.