Infectious canine hepatitis (ICH) is caused by canine adenovirus -1 (CAV-1) but we no longer have vaccines against this strain because they caused “blue eye”, a permanent protein-deposit blue opacity on one or both eyes. Instead, we vaccinate with canine adenovirus -2 (CAV-2), which is part of the kennel cough complex of viruses [CAV-2 is the “H” (or A2) in the typical DHLPP (DA2LPP) combination vaccine], to elicit cross-protection against CAV-1 as well.
At this point in time, my vaccine protocol does not recommend the CAV-2 vaccine for hepatitis and part of the kennel cough complex, because until just very recently, there have been no documented clinical cases of infectious canine hepatitis in North America for at least 12 years – and – the immunosuppression after CAV-2 vaccine in puppies lasts for 10 days afterwards. This immunosuppressive effect does not occur when adult dogs are vaccinated with CAV-2. [Phillips et al, Can J Vet Res 53: 154-160, 1989].
But, in the Northeast, wildlife (likely foxes) have been found at the Canada/United States border in New Hampshire and Vermont to be infected with CAV-1. Again, CAV-1 is the virus causing ICH in dogs and is cross-protected against by the CAV-2 vaccines. A litter of Rhodesian Ridgeback puppies became infected with ICH and some died. This infection was confirmed by Dr. Ron Schultz during the Fall of 2012.
So – in the Northeastern United States at least, we need to reconsider adding in the CAV-2 vaccine but not when the pups are young and can be immunosuppressed by the vaccine. Perhaps giving it at puberty would be safe – although you cannot buy CAV-2 vaccine by itself – only in a combination shot. Another alternative is to titer for hepatitis in dogs.