Ninety-one equine aortic and cranial mesenteric arterial segments were evaluated ultrasonographically in a water bath. On the basis of pathologic evidence of verminous arteritis, arterial segments were classified into 4 categories, and the ultrasonographic characteristics of each group were evaluated. Normal arteries (class 1) were ultrasonographically characterized by a smooth luminal surface layer and uniform wall thickness and echogenicity. Arteries with only histopathologic evidence of verminous arteritis (class 2) were ultrasonographically characterized by a smooth luminal surface layer, uniform thickness, uniform echogenicity, and the presence of a hyperechoic luminal layer. Arteries with both gross and histopathologic evidence of verminous arterities (class 3) were characterized ultrasonographically by an irregular luminal surface layer, varying wall thickness, varying wall echogenicity, and the presence of a hyperechoic luminal layer. The ultrasonographic characteristics of arteries with luminal thrombosis (class 4) were an irregular luminal surface, varying wall thickness, and nonuniform echogenicity.

Strongylus vulgaris, ponies (exper.), diethylcarbamazine did not prevent clinical or pathological changes due to migrating larvae, fewer adults recovered at necropsy from treated vs. untreated ponies

techniques to locate lesions and recover developmental stages of helminths from equine arteries, subperitoneum, liver, and lungs postmortem

Transrectal ultrasonography was performed on the cranial mesenteric artery and its major branches in 23 conscious adult horses. Ultrasonographically, 25 arterial segments were classified as either normal or abnormal. These ultrasonographic classifications were later compared with the gross and histologic evaluations of each artery following necropsy of each horse. In this study, transrectal ultrasonography as a diagnostic test for verminous arteritis had a 90% sensitivity for detecting normal arteries and an 86% specificity for detecting abnormal arteries, suggesting that ultrasonography may be useful in the antemortem diagnosis of verminous arteritis.

Strongylus vulgaris, establishment of patent infections in 6 of 8 helminth-free ponies given adult worms via nasogastric tube, removal of worms from cecum and ventral colon of donor horses, initial appearance of eggs in feces and maximum egg counts of recipients, percentage survival of adults after intragastric inoculation determined at necropsy

small and large strongyles, ponies, cambendazole, effects of periodic therapeutic dosing (1974-1978) on strongyle egg counts and on mares' reproductive performance with teratologic implications, critical test, comparison of benzimidazole-resistant species of small strongyles in 4 populations

Strongylus vulgaris, migrating larvae in pony foals, fenbendazole in controlled tests

gastrointestinal parasites, horses, anthelmintic efficacy of ivermectin, adverse local or systemic reactions not observed

Semiselective mesenteric arteriography was performed at regular intervals (inoculation weeks [IW] 0, 18, and 24) in 9 of 10 pony foals raised to be free of parasites. Fifty infective larvae (L3) of Strongylus vulgaris were administered weekly for 4 weeks, then every 2 weeks through the 20th week. Three ponies were given ivermectin (oral paste, 0.2 mg/kg of body weight) treatment at IW 8, 16, and 24. Four ponies were inoculated, but did not receive ivermectin, and a third group of 2 ponies acted as uninoculated controls. Control ponies did not have gross or arteriographic lesions, whereas the inoculated untreated ponies had gross and progressive arteriographic lesions typical of verminous arteritis. Arteriographic lesions in the ivermectin-treated inoculated ponies were not as severe those in the untreated inoculated group, and there was either a partial resolution or a lack of progression of arteriographic lesions in all treated ponies. One untreated inoculated pony did not have progressive arterial lesions as did the 3 others in the group, and may develop resistance to the parasite.

helminths of Thoroughbred horses with emphasis on stomach worms and tapeworms, numbers and infection rates according to host age and month of necropsy