The condition seen on this specimen is the result of infection with a papilloma virus. The virus stimulates the growth of abnormal warty tissue – which it actually is – that may take the form of small poorly formed antlers. Horned rabbits are more numerous and visible when rabbit populations are high and individuals come into more frequent contact. About 80-85% of those infected survive the affliction. Some have been seen near the Science Museum.

I have occasionally been questioned by callers about rabbits with “horns or antlers” and whether they had actually seen a jackalope. To help dispel the notion of that mythical creation of novelty taxidermy designed to represent a cross between a rabbit and deer, I proposed that this specimen be displayed.
– Dick Oehlenschlager, Biology