Intoxicação espontânea por Ipomoea carnea subsp. fistulosa (Convolvulaceae) em bovinos no Pantanal Matogrossense

A spontaneous Ipomoea carnea subsp. fistulosa (canudo, algodoeiro) poisoning of cattle in the county of Pocone, Brazilian Pantanal, is reported. The investigation began after 12 cattle had died from a flock of 500 animals maintained in an extensive area intensely infested by I. carnea subsp. fistulosa with scarce availability of other fodder plants. The deaths occurred from June to September of 2006. Clinical signs were loss of weight and neurological deficits with hypermetry and incoordination. No significant gross lesions were observed at postmortem examination of one bovine. Histological changes comprised widespread cytoplasmic vacuolation of neurons, cells of the thyroid, kidney and pancreas. Cattle with similar clinical picture, that had been removed from the area invaded by I. carnea subsp. fistulosa and placed into areas with native and Brachiaria sp. pasture, recovered clinically within 15 days.