Arsenic and metaldehyde toxicosis in a beef herd.

Over a 12-day period, 13 animals in a herd of 110 beef cattle developed ataxia with profound muscle fasciculations progressing to recumbency. Twelve animals (5 adults and 7 calves from 8-10 months of age) died, and 1 cow was euthanized. Hemorrhagic diarrhea occurred in some, but not all, animals. The onset of clinical signs was at least 12 hours after the cattle had gained access to contents of old buildings used for storage, and the majority of deaths occurred within 24 to 48 hours after the onset of clinical signs. Approximately 9 kg of unidentified pellets were found strewn in the barn area where the cattle had been. Autolysis considered more severe than expected for the postmortem interval, suggestive of high body temperature before death, and congestion of body tissues were the only significant findings detected in the cow that was euthanized and submitted for necropsy examination. The clinical history and lack of postmortem lesions were most consistent with toxicity. A toxic level of arsenic (6.18 ppm) was detected in the kidney, and metaldehyde was detected in the liver. The pellets were analyzed and found to contain both arsenic and metaldehyde, consistent with a discontinued molluscicidal product.

Equine cutaneous fungal granuloma: a study of 44 lesions from 34 horses.

Forty-four nodular and noninvasive cutaneous fungal granulomas were identified in 34 horses over a 14.5-year period. Cutaneous fungal granulomas were most common in young horses (mean age 6.1 +/- 4.2 years; range 1-19 years). There was no apparent breed or sex bias. Granulomas were either single or multiple, and most often occurred in the skin of the head and neck. The characteristic histological finding was a nodular dermal mass with a mean diameter of 7.3 mm (range 2.5-20 mm) and an intact overlying epithelium. Lesions most often exhibited intense lymphocytic inflammation, with admixed pyogranulomatous inflammation associated with a small to moderate number of fungal elements. Causative fungi were both pigmented and nonpigmented organisms of variable morphology. Penetrating plant material was identified in three cases. Granulomas caused by nonpigmented fungi were most common in horses from wet regions. Both pigmented and nonpigmented fungi were found in granulomas from horses in dry regions. Cutaneous fungal granulomas occurred in February through November, with peaks in April and July. No correlation of yearly incidence with annual average temperature or rainfall was detected. This study confirms that equine cutaneous fungal granuloma is relatively common in horses in the Pacific Northwest. Morphology of causative fungi was variable, but the signalment, history, and clinical and overall histological features were very similar. Surgical excision was curative.

A Reevaluation of the Host Range and Geographical Distribution of Claviceps Species in the United States.

A listing of host and state reports and distribution maps for 11 taxa of Claviceps occurring in the United States, including C. africana, C. cinerea, C. grohii, C. nigricans, C. paspali, C. pusilla, C. purpurea var. purpurea and var. spartinae, C. tripsaci, C. yanagawensis, and C. zizaniae, was prepared based on literature citations and examination of specimens from herbaria. The occurrence of C. ranunculoides is questioned based on examination of conidia and sclerotia from archived specimens. Collections of C. purpurea var. purpurea from grasses in the Pani-coideae were referred to other Claviceps spp. based on occurrence of macroconidia and micro-conidia. C. purpurea var. purpurea was found on 165 grass species within the continental United States and Alaska. The size of conidia of C. purpurea var. purpurea was found to be relatively stable across host and geographical regions. However, conidia of C. purpurea var. purpurea from hosts in the Aveneae and Meliceae (generally associated with wet habitats) were more variable in size and generally larger than those from other tribes in the Pooideae. Claviceps spp. in the continental United States occurred in diverse habitats, including temperate grasslands of the middle to northern latitudes (C. purpurea var. purpurea, C. nigricans) to the middle to southern latitudes (C. pusilla), coastal habitats (C. purpurea var. spartinae, C. ziza-niae), northern wetlands (C. grohii), southern temperate to subtropical grasslands (C. africana, C. paspali, C. tripsaci, C. yanagawensis), and arid southwestern grasslands (C. cinerea).