Canine distemper virus is a disease of dogs, and hopefully it’s just some nebulous illness you vaguely recall hearing about and not something you’ve had direct experience with. It’s most likely that you’ve heard of distemper because of the distemper vaccine, which is given as a core vaccine in each of your puppy’s routine vaccine appointments early on, and then every three years in adult dogs. The truth is, your dog is very, very lucky to have this vaccine around. The days before the distemper vaccine were pretty scary. The distemper virus was common and cruel—particularly bad years saw the dog population of entire towns taken out!
These days, distemper isn’t generally a problem for vaccinated house pets, but we do still see this deadly virus crop up from time to time, especially in rescue, shelter and pet store populations. When distemper outbreaks occur, they are devastating. In early March, for example, a shelter in Oak Ridge, Tennessee had to close its doors and euthanize thirty dogs because of an outbreak there. For shelter staff – who loved those dogs like their own – the outcome was heartbreaking.
Distemper outbreaks spread so rapidly because the virus is transmitted via oral and nasal secretions. So, sneezing and coughing dogs easily aerosolize the virus to nearby dogs. Sharing food and water bowls can also transmit the disease.
Once the virus enters the body, it goes to work on the respiratory tract before moving to the gastrointestinal tract and the central nervous system. Coughing and sneezing with nasal discharge, fever, and goopy eyes are classic symptoms of distemper, but vomiting, diarrhea, and tremors or seizures can also be seen if an adequate immune response is not mounted. Callousing of the nose and foot pads can occur, which is why distemper is sometimes called “hard pad disease.”
Neurologic signs can occur 1 to 3 weeks after exposure to the virus, but they can also cause symptoms months after apparent recovery. Twitching, seizures, and rigid muscles are all possible signs that the virus has invaded the central nervous system. Signs are generally progressive, but in some patients, the progression of signs eventually stops (hopefully at a point where the quality of life is still acceptable).
The extent of the disease in dogs relies on their ability to mount an immune response. There is no cure for distemper. Instead, we can only support an infected dog with medical therapy while their immune system tries to catch up, and for puppies and unvaccinated dogs, this is a difficult job to undertake. Dogs who are unlucky enough to get distemper can expect to be hospitalized for fluids, antibiotics for secondary bacterial infections, and general supportive nursing care.
There is good news in all of this doom and gloom, though. Distemper takes a toll on dogs, but it is possible for them to survive the infection. However, some survivors will go on to battle old dog encephalitis in their geriatric years due to the persistence of the virus in nervous system tissues. But the super good news is that distemper is so very easy to prevent.
As I mentioned at the start of this blog, the distemper vaccine is given to puppies as a core vaccine at 6 to 8 weeks of age and then boostered every three to four weeks until 16 weeks of age. It is given in combination with parvovirus, parainfluenza and adenovirus vaccines and is commonly called a “DHPP” or “DAPP” vaccine. After your dog’s one year old visit, he’ll only need the distemper vaccine every three years. Such an easy way to avoid a deadly disease!