Pigmentation of the viscera and carcasses (chromatosis) in sheep in the Brazilian northeastern region

Abstract

We report exogenous pigmentation in sheep grazing in native pastures in northeastern Brazil. The sheep carcasses from a farm were condemned at the slaughterhouse due to pigmentation of the carcasses and viscera. In visits to the farm, bluish-purple pigmentation of the mucosa was observed in the sheep. In two necropsied sheep, a bluish-purple pigment was observed in the skin, subcutaneous tissue, fat, muscles, cartilage, bones, serous membranes of the forestomachs, kidneys, adrenal glands, and the mucosa of the uterus, urinary bladder, urethra, vagina, trachea, bronchi, and bronchioles. Some bone surfaces, the intima of large arteries, tendons, muscle insertions, and ligaments had a yellow-brown or light brown pigment. However, the pigment was not observed upon histologic examination of tissues, suggesting that the pigmentation is caused by a plant. Two plants, Rhamnidium molle and Pereskia bahiensis, were fed to experimental sheep and rabbits, but did not cause pigmentation.