A case of Bovine Erythropoietic Protorphyria in a female limousin calf

Abstract

Bovine erythropoietic protoporphyria (BCEPP) is a rare genetic disorder predominantly affecting Limousin and, sporadically, Blonde Aquitaine cattle. It arises from diminished or absent ferrochelatase activity, causing the toxic buildup of protoporphyrin in tissues. This accumulation leads to photosensitivity and seizures upon exposure to sunlight.

Here, we report a case of a female Limousin calf exhibiting BCEPP signs, including photosensitivity, skin lesions, ataxia, and seizure. Clinical examination and ancillary tests ruled out photosensitivity related to direct ingestion or hepatogenous toxics. Photosensitivity due to aberrant porphyrin accumulation, specifically BCEPP and Congenital Erythropoietic Porphyria (CEP), emerged as the primary differential diagnoses. Notably, the absence of characteristic signs such as "pink tooth" and anaemia, which are indicative of CEP, distinguished BCEPP. A homozygous autosomal recessive mutation in the ferrochelatase gene (FECH) confirmed the BCEPP diagnosis by genetic testing. The animal's welfare led to euthanasia and subsequent farm control strategies aimed at preventing further genetic transmission. To eliminate the chance of transmitting the genetic mutation, the decision was made to switch to a pure Aberdeen Angus bull. In conclusion, this case emphasises the significance of a comprehensive diagnostic approach. The farm history, clinical examination, and ancillary testing helped to narrow down other differential diagnoses further. The distinction between BCEPP and CEP rested on observable clinical indicators and breed specificity. The targeted genetic testing confirmed BCEPP paving the way for the correct herd health approach.