There are four major infectious diseases seen in pet rabbits. Myxomatosis is spread by bites from mosquitoes, flies, fur mites, and fleas and can also be acquired from injuries caused by contaminated thorns or thistles. Subcutaneous swelling extends around the eyes, ears, and genital region and can progress to skin hemorrhages, breathing difficulties, decreased to no appetite, fever, generalized skin tumors, and death. Viral hemorrhagic disease is transmitted by direct contact with infected rabbits, rodents, and contaminated cages, dishes, and clothing. If signs are present, they include decreased appetite, fever, lethargy, collapse, convulsions, coma, difficulty breathing, foaming at the mouth, bloody nasal discharge, and death. Encephalitozoonosis causes a latent condition in rabbits. When signs do develop, the affected rabbit may develop dense white cataracts in one or both eyes, a head tilt, nystagmus, lack of appetite, difficulty walking, uncontrollable rolling over in one direction, tremors, and seizures. Pasteurellosis commonly causes abscesses, respiratory infections, and chronic inflammatory disease in rabbits. It can infect the nasolacrimal ducts, eyes, ears, and nose, and can cause abscesses of tooth roots, bones (particularly the jaw), skin, tissues under the skin, and internal organs.
As in humans, this is a sexually transmitted disease caused by a spirochete organism called Treponema cuniculi. It is a different spirochete from the human Treponema pallidium. Humans cannot get this particular organism from a rabbit.