Carrots, carrots, carrots, in a rabbit

Having looked at a case of too much carrot in a man, let us now peruse a rabbit:

“Hyperostotic polyarthropathy in a rabbit‐a suspected case of chronic hypervitaminosis A from a diet of carrots,” J. L. Frater, Australian Veterinary Journal, vol. 79, no. 9, 2001, pp. 608-611. The author, at the Unviersity of Melbourne, reports:

“Chronic hypervitaminosis A can occur in many species after excessive dietary intake of Vitamin A (retinol). The most common presentation of chronic hypervitaminosis A is a polyarthropathy with hyperostosis and ankylosis of various joints. This case report describes a probable case of naturally occurring hypervitaminosis A-induced polyarthropathy in a rabbit after chronic ingestion of a diet made up almost exclusively of carrots. Carrots do not contain retinol, but are rich in provitamin A (or beta-carotene). Rabbits are unique in that they can convert 100% of dietary beta-carotene into retinol. A syndrome of naturally occurring hypervitaminosis A-induced polyarthropathy has not  been described in a rabbit before.”

(Thanks to investigator Kurt Verkest for bringing this to our attention.)