I recall from Heinlein's _Farnham's_Freehold_ that there is a disease
condition rabbits can have that is communicable to humans....
Wish I could remember its name....

Tuleremia?

http://www.mayoclinic.com/invoke.cfm?id=HQ01391

Sounds pretty bad:

http://hopkins-id.edu/bioterror/bioterr_10.html