I realize it is quite common for 'people on the street' to believe that all coccidia infect all animals, and there are even a few vets out there who apparently were not paying attention that day in lecture, but honest. There are some Eimeria spp that will infect species from several different genera, I *think* there may even be one that crosses family lines, but there is no good evidence of anything affecting both mammals to birds (in general). The seven species of Eimeria that can infect chickens are *different than* the species of Eimeria that can infect rabbits.
I ended up sort of stalling out with the article (I wanted a vet who would comment *on the record* on the subject of chickens+buns w/r/t other diseases, not yet found one, also did not exactly knock myself out looking as this is not the central activity of my life
) so it remains unpublished at the moment.
However you can find all sorts of book and journal references to the host specificity of Eimeria, e.g. things like (via a quick google)
http://biology.unm.edu/biology/coccidia/eimeriabiol.html
www.merckvetmanual.com/mvm/htm/bc/21200.htm
http://wildlife1.wildlifeinformation.org/S/00dis/Parasitic/Hepatic_coccidiosis_rabbits.htm
http://books.google.ca/books?id=pv8...snum=2&ved=0CAgQ6AEwATgK#v=onepage&q=&f=false
Or you could find yourself a parasitologist who works with coccidial organisms, or a (preferably research or university-vet-school) vet, and ask them if you want
Mind, this still leaves various *other* things that can pass between chickens and rabbits, e.g. salmonella, pasteurella, listeriosis, etc.
Pat