Canine herpesvirus infection is a widespread, often fatal disease, usually infecting puppies 1-3 weeks old. In adult dogs, it usually results in lesions on the reproductive organs, and is associated with an upper respiratory infection. Canine herpesvirus affects the dog’s respiratory and reproductive systems, and can quickly result in death in unborn or newly born puppies.
Signs & Symptoms of Canine Herpes
Signs and symptoms in puppies can develop rapidly and often are fatal within 48 hours. Signs of herpesvirus in puppies may include:
- Respiratory signs and nasal discharge
- Abdominal pain and enlargement
- Soft, yellow-green feces
- Nosebleeds or small bruises on mucous membranes
- Rash on belly
In adult dogs, the following symptoms will usually occur:
- Vaginal pain and pus-filled discharge in adult females
- Abortion, stillbirth, or infertility in adult females
- Refusal to nurse in adult females
- Recurring lesions on reproductive organs
- Inflammation of the foreskin of the penis in adult males
Adult dogs can live for years as carriers without showing any symptoms. They are still able to transmit the disease during these times and are referred to as "asymptomatic carriers." Lesions in adult females may recur during heat cycles.
Causes of Canine Herpes
Dog herpes is caused by a virus that is easily transmitted from a mother to her puppies, sometimes prior to birth. Because the herpesvirus can reside in the respiratory system, transmission to puppies from direct or airborne contact with oral or nasal discharge is common. It can also be transmitted from a mother to her puppies via direct contact with her vaginal secretions. Herpes is easily transmitted from puppy to puppy as well. Adults can get the herpesvirus from sexual contact with another infected adult. Symptoms develop about one week after exposure to the herpesvirus.
Diagnosis of Canine Herpes
Diagnosis always begins with a complete history and a physical exam. Most often, the distinct lesions and sudden death will distinguish herpesvirus from parvovirus or coronavirus. While herpesvirus can be isolated from infected tissue (such as that from the kidney, liver, or spleen), this is usually done post-mortem. Hemorrhagic lesions can also be seen throughout the body after the puppy’s sudden death. In adults, lesions seen on the reproductive organs are characteristic of herpes.
Treatment for Canine Herpes
Your veterinarian will likely treat herpesvirus based on the symptoms. Puppies will be monitored closely and likely given anti-diarrheal medication. Fluids and force-feeding may be necessary to counteract refusal to eat and lethargy. Keeping puppies warm in an incubator, or by other means, has been shown to reduce mortality in some cases. Puppies who survive a herpes infection will suffer permanent damage to their lymph nodes, brain, liver, and kidneys.
Prevention of Canine Herpes
Canine herpesvirus is one of the leading causes of death in puppies 1-3 weeks old. There is currently no vaccine for herpesvirus. The best way to prevent spread of herpes is to keep known carriers away from other adult dogs. This especially pertains to females that are in their heat cycle.
Under laboratory conditions, it has been shown that infected, unborn puppies may be saved by being removed via cesarean section and raised in isolation away from their mother. Infected, pregnant mothers will develop antibodies to the herpesvirus after her first litter, and will pass these on through her milk to her next litter.