Experimental Solanum malacoxylon poisoning in calves.

SUMMARY To study the effects of Solanum malacoxylon in young cattle the dried leaves of the plant were administered to two calves for 3–6 periods of 4 days each, separated by periods of 12 days without dosing. Increasing dose levels were used because of the low susceptibility of the calves to the plant material. The calves proved less susceptible to the plant material than the older animals studied previously. Intermittent administration of plant material was shown to produce a similar picture to that seen in natural cases of the plant poisoning. Administration of the plant caused a rapid rise in serum calcium accompanied by a slower rise in serum inorganic phosphorus. These increases were associated with a loss of bodyweight, stunted growth and inappetance, particularly when the higher dose levels were used. Macroscopic and histological examination at post-mortem revealed only slight changes in the animal killed after 36 days, but the animal killed after 87 days showed moderate (50 per cent) calcification of the aorta and areas of calcification in the lung, kidney, and other soft tissues.