Outbreaks of dermatopathy caused by Tephrosia noctiflora intoxication in Brazilian cattle.

This study aims to update the knowledge concerning the intoxication by Tephrosia noctiflora in Brazilian cattle herds by reporting new cases of intoxication in lactating cows, their calves and bulls and highlight the epidemiology, clinical signs, pathogenesis, gross, and microscopic lesions. The morbidity and mortality of this intoxication in the farms studied was low. Gross lesions in all affected cattle consisted of dermatitis with hyperpigmentation, crusts, ulceration, erythema, and lichenification in the skin of limbs, ventral abdomen, perianal and perineal areas of lactating calves and adult cattle. Microscopically, the main lesion observed consisted of severe dermatitis with parakeratotic hyperkeratosis, papillated proliferation, and diffuse, accentuated lymphoplasmacytic inflammatory infiltrate in the epidermis and dermis. The presence of skin lesions mainly in the limbs and ventral abdomen of cattle implies the pathogenesis of intoxication is related to a primary contact dermatitis, and the occurrence of similar lesions on the skin of nursing calves reinforces this hypothesis. The putative toxins of T. noctiflora have been thought to be rotenoids. Additional work is needed to define better if these compounds are the main toxin responsible for the dermatopathy observed in these herds.

Tremorgenic syndrome in suckling lambs due to poisoning by Ipomoea asarifolia

The aim of this study was to describe the clinical, pathological and epidemiological aspects of an outbreak of tremorgenic syndrome in suckling lambs associated to Ipomoea asarifolia poisoning occurred in the metropolitan region of Recife, northeastern Brazil. Eight suckling Dorper lambs presented clinical signs after their mothers being kept in pasture invaded by I. asarifolia. Sixty percent of adult sheep, including lactating ewe, only exhibited engorged episcleral vessels. The suckling lambs exhibited neurological signs, such as head and neck tremors, dysmetria, wide-based stance, uncoordinated gait, unusual standing and imbalance followed by falls. These signs became more evident when the animals were forced to move. No gross lesions were found in a necropsied lamb that had died spontaneously. The histological findings were axonal spheroids in the cerebellum granular layer and numerous necrotic neurons in the cerebral cortex and cerebellum molecular layer. This study demonstrates that Ipomoea asarifolia causes tremorgenic syndrome. The toxin is eliminated through milk and suckling lambs exhibit a greater susceptibility compared to adult animals.

Tremorgenic syndrome in suckling lambs due to poisoning by Ipomoea asarifolia

The aim of this study was to describe the clinical, pathological and epidemiological aspects of an outbreak of tremorgenic syndrome in suckling lambs associated to Ipomoea asarifolia poisoning occurred in the metropolitan region of Recife, northeastern Brazil. Eight suckling Dorper lambs presented clinical signs after their mothers being kept in pasture invaded by I. asarifolia. Sixty percent of adult sheep, including lactating ewe, only exhibited engorged episcleral vessels. The suckling lambs exhibited neurological signs, such as head and neck tremors, dysmetria, wide-based stance, uncoordinated gait, unusual standing and imbalance followed by falls. These signs became more evident when the animals were forced to move. No gross lesions were found in a necropsied lamb that had died spontaneously. The histological findings were axonal spheroids in the cerebellum granular layer and numerous necrotic neurons in the cerebral cortex and cerebellum molecular layer. This study demonstrates that Ipomoea asarifolia causes tremorgenic syndrome. The toxin is eliminated through milk and suckling lambs exhibit a greater susceptibility compared to adult animals.(AU)