Yes, they can be harmful to pets. Humans are aware that they should not do anything in order to feel the opossum feel threatened so that they will be left alone but pets may have the tendency to chase opossums. There may be moments when instead of just running away, opossums would fight back and bite the house pets.
This can make house pets vulnerable to a lot of diseases. Opossums are known to carry different diseases that can make your pet seriously sick. It is not only pets that can become sick because of the attack of the opossum. Humans can be affected too.
