Canid alphaherpesvirus 1 (CaHV-1), also called Canine herpesvirus (CHV), is a virus of the family Herpesviridae which most importantly causes a fatal hemorrhagic disease in puppies (and in wild Canidae) less than two to three weeks old.

[5] Symptoms include crying, weakness, depression, discharge from the nose, soft, yellow feces, and a loss of the sucking reflex.

[7] There is a high mortality rate, approaching 80 percent in puppies less than one week old,[8] and death usually occurs in one to two days.

[9] In puppies three to five weeks old, the disease is less severe due to their ability to properly maintain body temperature and mount a febrile response.

[11] In adult dogs, the virus infects the reproductive tract, which allows it to be sexually transmitted or passed to puppies during birth.

Most adult dogs become infected by inhaling the virus via airborne particles spread by coughs or sneezes.

[9] Bitches that have lost puppies to the disease may have future litters that survive due to transfer of antibodies in the milk.

[13] Studies of using CHV as a viral vector for gene therapy in dogs and as a basis for recombinant vaccines are ongoing.