Canine adenovirus type 2 (CAV-2) is considered a core vaccine, primarily because it is necessary for the prevention of canine adenovirus type 1 (CAV-1) (against which it cross-protects),¹⁸ the cause of infectious canine hepatitis, historically recognized as a severe and often fatal disease of canids. Although uncommon, sporadic cases of CAV-1 infection are still reported.¹⁹ Vaccination schedules for parenteral CAV-2 vaccines follow the recommendations for CDV and CPV, and CAV-2 is usually a component of combination vaccines.

CAV-2 can also cause tracheobronchitis and is part of the canine infectious respiratory disease (CIRD) complex. Given in combination with canine parainfluenza virus (CPIV) and Bordetella vaccines, MLV CAV-2 vaccine can be administered intranasally (IN) to puppies as young as 3 wk of age, as mucosal immunity is not blocked byMDA.