The rate of canine herpesvirus infection in dogs ranges from 20 to 98 percent worldwide, depending on the region, according to the Merck Veterinary Manual. This type of herpesvirus affects only dogs, not people or other pets. Dogs exposed to canine herpesvirus carry it with them for the rest of their lives. Canines recently infected with herpesvirus often suffer from reproductive issues, including passing the virus on to newborn puppies.
While often fatal in puppies, where it causes "fading puppy syndrome" and neonatal death, canine herpesvirus can affect dogs later in life. However, these dogs rarely develop serious illness. Canines exposed to the virus past the age of 3 weeks usually remain asymptomatic. There is currently no vaccine available for canine herpesvirus in the United States.
Herpesvirus transmission occurs via direct contact between an infected and noninfected canine. The virus passes through saliva and nasal secretions. Although it causes problems with pregnancy, canine herpesvirus is not generally a sexually transmitted disease, although such transmission is possible. Adult dogs with herpesvirus might experience mild upper respiratory infections, including ocular discharge. This is similar to "kennel cough," and often mistaken for it. While the dog hardly seems ill, that's a stage where he readily can pass on the virus to other canines. Whenever infected dogs are stressed, they are more likely to shed the virus.
Pregnant dogs infected with herpesvirus might abort their fetuses or deliver stillborn puppies. These dogs don't appear ill during their pregnancy. Puppies born to a recently infected dog developing symptoms before the third week of life often succumb to the disease. The virus passes to the puppies soon after birth, with an incubation period of six to 10 days. At that point, affected puppies stop nursing and experience trouble breathing. Puppies might die so quickly that their owners never realize they were sick. If a puppy in a litter dies, save the body and take it, along with the mother and surviving puppies, to an emergency vet. The majority of puppies afflicted before 21 days of age will die. After that time, they are better able to regulate their body temperature and stave off the infection.
Not all infected adult dogs carry antibodies against canine herpesvirus for the long term. Antibodies might be present for several months after infection and then disappear, or be evident for the rest of the animal's life. Potential pregnancy is the primary reason for antibody testing in dogs. If the breeding female tests positive for herpesvirus before pregnancy, that's not an issue. She'll pass antibodies on to her puppies. If she tests negative and is exposed at a certain point during pregnancy, that's where the trouble lies. If you breed a dog testing negative for herpesvirus, keep her away from other dogs for the last three weeks of her eight-week gestation, as well as for the first three weeks after the puppies are born.