Retrospective analysis of hairy vetch (Vicia villosa roth) poisoning in Argentina (2004-2019)

Plants causing poisoning outbreaks of livestock in South America: A review

This paper reviews toxic plants for livestock in South America. We included 219 plants in this review, considering only the plants that caused at least one demonstrated outbreak of poisoning. Plants reported as toxic in other regions and present in South America, but with no confirmed outbreaks of poisoning in this region, are not included. We report the main aspects of the epidemiology, clinical signs, pathology and economical importance of the poisonings. Initially, the toxic plants are described based on their toxic compounds, but because the toxic compound is unknown in 92 (42%) of the plants we also classify them according to the affected system. This review highlights the great diversity of toxic plants capable of affecting livestock in South America, and for this reason studies in this regard should be intensified.

[Vetch poisoning in a Bavarian cattle herd - A case report from a pathological perspective]

In a herd of 40 cattle of the Holstein-Friesian breed, 6 animals were euthanized for severe pruritus, fever and skin lesions. Pathomorphological examination of 3 animals revealed multisystemic granulomatous inflammation involving multinuclear giant cells. The content of vetch in the feed used and the characteristic histology led to the diagnosis of vetch poisoning.

Dermatopathy caused by Tephrosia noctiflora intoxication in cattle

An outbreak of a disease characterized by emaciation, dermatitis with erythema, alopecia, foul-smelling exudation, crusting, hyperpigmentation, lichenification, and edema of fore- and hindlimbs, chest and dewlap is described affecting cattle in the State of Alagoas, Northeastern Brazil. Microscopically, the main lesions were characterized by diffuse dermatitis with infiltration of lymphocytes, histiocytes, parakeratotic hyperkeratosis and acanthosis. The plant Tephrosia noctiflora, which exhibited signs of consumption, infested the grazing areas of cattle. To test its toxicity, T. noctiflora was harvested, dried in the shade, crushed and sourced at a concentration of 50% mixed with commercial food for three guinea pigs. The main clinical signs in guinea pigs included weight loss and multifocal, moderate to severe areas of alopecia, diffuse erythema of the skin, vaginal edema and hematuria. Microscopically, lymphocytic and histiocytic dermatitis, parakeratotic hyperkeratosis and acanthosis were noted in guinea pigs. This experiment confirms that T. noctiflora is the cause of outbreaks of dermatitis observed in cattle grazing in areas infested by this plant.