Photosensitivity in feedlot calves apparently related to cocoa shells
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Updated: Aug 30, 2026

12:37
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
1Hachaklait Gedera and the Koret School of Veterinary Medicine, the Hebrew university of Jerusalem, POB 12, Rehovot 76100, Israel.
Abstract:
Primary photosensitization was observed in 11/78 cross-breed calves. The skin lesions were diffuse dermatitis with thickening and wrinkling with areas of alopecia. The severe photosensitivity dermatitis was associated with cocoa shell ingestion. The lesions resolved after removal of the cocoa shells from the feed ration and prevention of exposure to sunlight. Cocoa shells may contain photodynamic agents that cause photosensitization in calves.

