We do not have any direct experience with CHV in our kennel.
Recently, we saw an entire litter that died from CHV that was posted online by an American Bulldog breeder. We wanted to learn about CHV and this is what a breeder who also works at a veterinary clinic told us:
1. An adult dog that gets infected with CHV will likely show no symptoms, and so long as the the dog has good immunity, anti-bodies should protect the dog from CHV becoming a problem.
2. Apparently, the amount of time it takes for an adult dog to develop immunity against CHV after exposure is about 30 days.
3. CHV is highly contagious and can be easily passed through nose, mouth, and breath – so sniffing and licking is enough. So if a CHV-infected dog interacts with a clean dog, there is apparently always a chance of passing on the infection.
4. If you breed a CHV-positive male with a CHV-negative female, so long as the female has a strong immune system, she will develop anti-bodies against CHV in 30 days after breeding takes place, and this immunity will be passed on to the puppies. Puppies will be CHV-positive but should have the necessary anti-bodies to keep the disease suppressed their entire life and will not show any symptoms.
5. If you breed a female that is already CHV-positive but otherwise shows no symptoms of the disease, then the resulting puppies will be CHV-positive but should not be affected, as they will have the anti-bodies passed down from the mother.
6. THIS IS THE BIG ONE: If your female is CHV-negative and you breed her to a CHV-negative male, and then she gets infected through an interaction with a CHV-positive dog in the last 30 days of her pregnancy, she is bound not to have developed the anti-bodies in time, the resulting puppies will be born CHV-positive, and will likely all die.
So, if you have a CHV-positive female who is not showing any symptoms and is healthy with a strong immune system, then you likely shouldn’t have anything to worry about breeding her. Of course she will likely pass on CHV to the male during the breeding if he is CHV-negative.
BUT, if you have a CHV-negative female, here are the precautions to take:
After breeding her, ensure that she is not exposed to ANY foreign dogs during her entire pregnancy and probably until the puppies are at least 8 weeks old. If you have any other dogs living in the same environment with the female, then they too cannot be exposed to ANY foreign dogs during this period. If you take another dog from your yard on a walk to the park and he gets infected from interacting with a CHV-positive dog, he WILL pass it on to your pregnant female.
So, COMPLETE QUARANTINE OF ALL DOGS you have during pregnancy and until after the puppies are 8 weeks old.
You do not have to worry about your dogs infecting each other within the yard/home if you observe strict quarantine, as they would have already infected each other long ago if anyone was CHV-positive, and (5) above would apply.