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Hearts and flowers: Bryophyllum poisoning of cattle
Author(s) -
McKENZIE R A,
DUNSTER P J
Publication year - 1986
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1986.tb03000.x
Subject(s) - biology , sudden death , veterinary medicine , medicine , zoology
SUMMARY Findings from natural cases and experiments with cattle emphasise that flowering plants are the most important form of Bryophyllum (Kalanchoe) spp in poisonings in Australia. The main life‐threatening lesion is myocardial. The effects on the alimentary tract are less important than was believed previously. B. tublflorum, B. daigremontianum x B. tublflorum, B. pinnatum and B. proliferum caused 41 recorded poisoning incidents affecting 379 cattle in Queensland between 1960 and 1984. Poisoning occurred between May and October—the flowering season of these plants. Experimental B. tublflorum poisoning and natural poisonings produced anorexia, depression, ruminal atony, diarrhoea, heart rate and rhythm abnormalities, dyspnoea and death. Increased plasma concentrations of urea, creatinine and glucose and decreased chloride were measured experimentally. Both natural and experimental cases had myocardial degeneration and necrosis with haemorrhages of the heart and alimentary tract Cattle with severe dyspnoea had atelectasls and emphysema of the lungs. Some cattle had mild nephrosis. The median lethal doses of B. tubiflorum flowers, roots and leaf plus stem were 0.7,2.3 and 5.0 g dry matter/kg liveweight respectively (7,7 and 40 g wet weight/kg). Bufadienolides have been isolated recently from B. tublflorum flowers and the syndrome is consistent with cardiac glycoside poisoning.