Morte súbita em bovinos causada pela ingestão de Pseudocalymma elegans (Bignoniaceae) no município de Rio Bonito, RJ

Abstract

Natural poisoning by Pseudocalymma elegans is described in a cow in the county of Rio Bonito, RJ. Also decribed is the experimental reproduction of this poisoning in three calves (1.0, 0.5 and 0.25 g/kg of the fresh plant) and in five rabbits (0.5 0.25 0.125 0.0625 and 0.0312 g/kg of the dried and ground plant) with the plant collected in the area where the deaths had occurred. Post-mortem and histopathological examinations of the natural case in the cow did not reveal significant alterations. Oral administration of 1g/kg of the sprouts of P. elegans caused death of the calf 5hours and 30 minutes after beginning of the administration of the plant. The dose of 0.5 g/kg caused death of the animal after 76 hours and 36 minutes. The 0.25g/kg dose caused only clinical signs which consisted of heart palpitation and arrhythmia, increase of breathing frequency, reluctance in moving, positive vein pulse, ingurgitated jugular veins, mooing, falling down, peddling movements followed by death. At post-mortem examination the lesions were those of acute heart insufficiency, and histopatologic examination revealed the typical kidney lesion (hydropic degeneration in the distal convoluted tubules) seen in the poisoning by plants that cause "sudden death". In the experimentally poisoned rabbits the clinical course was from less than one to two minutes. The histopatological examination of the kidney of two rabbits also revealed that characteristic microscopic kidney lesion. This is the first description of a natural case of P. elegans poisoning in cattle with post-mortem and histopatological description. The occurrence of the plant in the county of Rio Bonito had not been known by the veterinarians. It is conluded that the plant has a higher toxicity as described before.