Opossums show a robust resistance to many viruses and rarely contract rabies, parvovirus, distemper, or feline hepatitis, the Alabama Cooperative Extension System says. However, opossums can carry many diseases, including leptospirosis, tuberculosis, relapsing fever, tularemia, spotted fever, toxoplasmosis, coccidiosis, trichomoniasis, and Chagas disease.    According to the Wildlife Medical Clinic at Illinois, the Virginia opossum has one of the lowest risks for developing and spreading rabies. Their low body temperature makes it difficult for the rabies virus to replicate within the opossum's body.   Opossums may transmit diseases to pets and humans through scratches and bites. They may quickly attack you if they are startled, especially as a means to escape after playing dead.   An opossum's urine and feces can also transmit several illnesses, such as leptospirosis and salmonella, so handle any waste matter with the proper precautions and care.   Mites, lice, ticks, and fleas often infest opossums and can transmit to your cat or dog.