Parvovirus in dogs is likely to be caused by external infection. For example, dogs may be infected with parvovirus through direct contact with dogs with parvovirus, or through contact with their feces, urine, vomitus, secretions, etc. Parvovirus spreads very quickly, so healthy dogs are at high risk of infection if they come into contact with sick dogs.

In addition, eating leftovers, greasy food, etc. may cause gastrointestinal sensitivity in dogs, reduce immunity, and increase infections. The risk of parvovirus and the high salt content and bacteria in leftovers pose a threat to the health of dogs.