[Varying sensitivity to copper poisoning in the sheep and cattle of Pirdop District]

The clinical picture manifested by sheep and cows in the region of Pirdop has been followed up in the course of three years. The content of copper was quantitatively determined in the milk, liver, kidney, spleen, and skeletal musculature of 20 cows and 50 clinically normal and 50 clinically affected sheep exibiting a hemolytical crisis. Though the animals were fed one and the same type of forages the amount of copper in the liver of cattle was within the range of 48 up to 98.54 mg/kg, and in sheep it ranged from 84.9 up to 828 mg/kg dry matter. This explains the low sensitivity of cattle as compared to sheep so far as copper intoxication is concerned. The deposition of copper in the kidneys, spleen, and skeletal musculature started from the beginning of the hemolytical crisis, and in the liver--prior to it.