I am obliged to report that which is reported, but not to believe it.
—Herodotus, The History, VII, 152
Dog-rabbit hybrids are very rarely mentioned in the literature. Indeed, there seems to be but a single, brief news report of such a cross on record. Such a cross would, of course, be extremely distant. Nor is the alleged hybrid even pictured. So this cross is very poorly documented (as reflected in the low temperature on the Reality Thermometer at right).
It is, however, true that numerous videos on YouTube do show small dogs mating with rabbits, which at least demonstrates that the requisite mating occurs with some frequency. The reported inviability of the hybrid is, however, consistent with a distant cross, since the hybrids from such crosses do seem to be more frequently inviable than those from close crosses.
Among domestic animals rabbits and dogs are both among the most promiscuous in their choice of mate. Indeed, both will attempt to mate even with various types of birds, as documented in YouTube videos, for example, the one at right. So it is not surprising, in itself, that the two would choose to mate.
The following news item is the only report of such a hybrid that extensive search has thus far revealed. It appeared on page 5 of the December 16, 1932, issue of The Burrowa News, a newspaper published in Boorowa, New South Wales, Australia (access source):
An affection between a half-bred fox terrier and a thorough bred female Angora rabbit led to the birth of a peculiar little creature, half dog and half rabbit, according to the owner of the animals, Mr. Victor Morehead, well-known business man of Minnamurra Avenue, Earlwood.
The freak died, however, a few hours afterwards and Mr. Morehead has preserved it.
More like a tiny puppy than a rabbit, it is black and white and has rabbit paws, legs and ears, but a dog-like head, tail and body.
Mr. Morehead said it was impossible for anyone to have played a joke on him, and there had been no other rabbits near the mother rabbit for more than 12 months.
The following is a list of reported dog crosses discussed on this site. Some of these crosses are much better documented than others (as indicated by the reliability arrow). Moreover, some are extremely disparate, and so must be taken with a large grain of salt. But all have been reported at least once.
By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).
Human Origins: Are we hybrids?
On the Origins of New Forms of Life
Cat-rabbit Hybrids: Fact or fiction?
Georges Cuvier: A Biography
Prothero: A Rebuttal
Branches of Biology