Dogs and puppies are infected orally, and the virus is spread transplacentally to the fetuses.

Symptoms are seen most commonly between the ages of one and three weeks[4] and include severe diarrhea, difficulty breathing, and anorexia.

When the dam is infected between 30 and 35 days, the puppies were sometimes born with myocarditis and anasarca.

[4] Pathological lesions in fetuses in experimental infections were found in the lung and small intestine.

The NP1 protein, unique to the Bocaparvovirus genus, appears to be critical for optimal viral replication, as the NP1 knockout mutant of MVC suffers from severe impairment of replication.