canine distemper vaccine

Canine Distemper Virus (CDV) is one of the most dangerous infectious diseases in dogs and is the second-most fatal disease to dogs in the world — rabies being the first. In the United States, CDV mostly affects unvaccinated puppies. The severity of the infection depends on the strain, the host, and the animal’s immune response and vaccination status. Despite this, all strains are incredibly difficult to treat

The disease itself is closely related to human measles and can infect most carnivorous animals, both marine and on land. It’s spread mostly through bodily secretions such as urine and can be prevented

Symptoms of Canine Distemper Virus 

CDV is tricky, because it usually doesn’t have any early symptoms. If your dog is due for bloodwork, a vet may notice they have a low white blood cell count, but that is usually the only early sign of this disease. 

If the dog’s immune system can’t fight off the disease, it will eventually move to your dog’s epithelial tissues and the central nervous system. After that, one of three things typically occurs: 1) the infection resolves on its own; 2) your dog becomes a silent carrier; or 3) the infection gets worse.

Silent carriers can infect other dogs. They may also develop thickening of the footpads and neurologic symptoms later on.

If a dog’s immune system isn’t adequate to defend against the infection, your dog will start showing active symptoms. Early symptoms can include:

  • Mild conjunctivitis (eyelid swelling)
  • Discharge from the nose and eyes
  • Lethargy
  • Fever
  • Loss of appetite

As the infection progresses, there will be upper respiratory symptoms like coughing, shortness of breath and even pneumonia. Gastrointestinal symptoms like vomiting, diarrhea with or without blood, and severe dehydration typically follow.

In its mildest form, CDV is often confused with kennel cough or mild allergies. At the other end of the spectrum is sudden death as a result of the infection.

Neurologic Impairment

Dogs who recover will likely develop neurologic symptoms. Neurologic impairment can also appear alongside systemic illness (within a week of your pup getting sick), or can take years to develop. It’s different in all dogs, but the likelihood of them developing neurological impairment is moderate — up to 30% of dogs develop them. 

Symptoms depend on the area of the nervous system involved and can include:

  • Involuntary muscle twitching
  • Seizure episodes sometimes called ‘chewing gum fits’
  • Lack of coordination of muscle movements
  • Partial or complete paralysis of limbs
  • Brain disturbances and eye problems

Unfortunately, neurologic symptoms are typically not reversible and are often progressive.

Preventing Canine Distemper

Thankfully, you can protect your dog from CDV with a recurring vaccination. They likely are already vaccinated from it if you adopted them as an adult. If they’re a puppy, make sure they get this shot to keep them healthy and safe. 

The new American Animal Hospital Association (AAHA) vaccination guidelines recommends re-vaccination for distemper every three years. However, the AAHA also makes note that CDV vaccines are known to provide protection against the disease for at least five years.

It’s also very important that your pet’s immune function isn’t compromised by unnecessary vaccinations, overprescribed veterinary drugs and excessive use of heartworm and flea/tick preventives.