Distemper in Dogs: Signs and Symptoms


Dogs have been man’s best friend since prehistoric times. According to the American Veterinary Medical Association, the United States is home to over 69 million dogs with an average 2.6 annual visits to the vet per each household.

Even before they became our best friends, dogs have had to grapple with a wide range of diseases and disorders, and while you can do your best to keep your pups healthy, they can still ultimately come down with the occasional illness.

Canine distemper is one of the most common illnesses among dogs. This article will take a closer look at this illness, the signs and symptoms you should keep an eye out for, and treatment options to help your pup get back into great shape.

What is Canine Distemper?

Canine distemper, alternately known as hardpad disease, is a highly contagious and potentially deadly viral disease that is most common in dogs but can be found in a variety of other animals, including coyotes, wolves, foxes, pandas, skunks, and ferrets.

Canine distemper should sound familiar to any dog owner because its vaccine is one of the core vaccinations given to dogs, along with the rabies, parvovirus, and canine adenovirus vaccines.

What Causes Canine Distemper?

Canine distemper is caused by a virus in the Paramyxoviridae family. The viruses that cause human measles, rinderpest in cattle, and seal distemper also belong to this same family.

The virus spreads quickly through a dog’s body, attacking the gastrointestinal, respiratory, and nervous systems. It can affect any dog of any breed, but puppies and dogs who have not been vaccinated are at a higher risk of getting canine distemper.

How Does Canine Distemper Spread?

Distemper in dogs can spread through three general means:

  • Direct contact with an object or infected dog or animal with the canine distemper virus
  • Airborne exposure to the virus
  • Through the placenta

In a lot of ways, the canine distemper virus is like the common cold virus in humans. When a dog or wild animal carrying the virus coughs, barks, or sneezes, it releases the virus into the air via microscopic water droplets. If your dog was to breathe those droplets in or come into contact with a food or water bowl that the droplets landed on, he may end up contracting the virus.


The good news is that the virus can’t last long out in the open, on surfaces throughout your home. You can easily eliminate the virus with a household cleaner or disinfectant. Unfortunately, dogs with distemper can shed the virus for months, so even if the dog has been treated or shows no symptoms, they may still be able to spread it to other pups they meet.

What makes distemper even more difficult to deal with is that it is so prevalent in wildlife. Raccoons, wolves, foxes, skunks, coyotes, and other common critters can get distemper. An outbreak of distemper in your local wildlife makes it easier for your dog to potentially contract the virus without ever even coming into contact with another dog.

Symptoms of Canine Distemper

Canine distemper can exhibit itself through a variety of symptoms that vary based on the advancement of the disease and your own pup’s health and immune system. When the virus enters your dog’s system, it proceeds to the lymphatic tissue in his respiratory tract where it reproduces and spreads to the rest of the lymphatic system, the gastrointestinal tract, the urogenital epithelium, the optic nerves, and the central nervous system.

The complexity of this spread leads to symptoms happening in two different stages. In wildlife, the symptoms of distemper resemble those of rabies.

Stage One of Canine Distemper

The initial symptoms of canine distemper that are most obvious are a sudden loss of appetite, watery or pus-like discharge from the nose and eyes, and a high fever usually going above 103.5 degrees Fahrenheit. The fever usually develops 3 to 6 days after the initial infection, but all symptoms depend on the severity of the virus and your dog’s immune system.

Other general symptoms you can expect in this first stage of distemper include:

If the infection persists, your dog can develop hyperkeratosis of his nose and paw pads, which is where canine distemper gets its alternate name of hardpad disease. Your dog’s foot pads literally harden, thicken, and enlarge, causing significant pain and discomfort.

Canine distemper also puts your pup at risk of a secondary bacterial infection. The distemper virus heavily compromises your dog’s immune system, allowing for an easy backdoor for secondary infections. Secondary bacterial infections can cause a variety of symptoms in your dog’s respiratory and gastrointestinal tracts, including:

  • Diarrhea
  • Vomiting
  • Labored or difficult breathing
  • Pneumonia
  • Changes in respiratory rate

Stage Two of Canine Distemper

As the virus progresses, it can eventually make its way to your dog’s central nervous system and cause some serious damage. In the secondary stage, your dog may exhibit neurological signs that can be disturbing for the owner. These neurological signs include:

  • Head tilting
  • Circling
  • Seizures
  • Full or partial paralysis
  • Muscle twitches
  • Repetitive eye movements (known as nystagmus)
  • Convulsions accompanied by chewing motions and increased salivation


Diagnosing Canine Distemper

Vets do have effective tests to determine if your dog is suffering from canine distemper, but the results of these tests may not always be reliable. Instead of testing just for canine distemper, your vet will probably take a look at the bigger picture, from your dog’s health history to specific symptoms to physical examination, to truly determine if your dog has distemper and what stage it may have progressed to.

Some common tests that vets perform to diagnose canine distemper include:

  • Urine analysis – This test may show a reduced number of lymphocytes, which are the white blood cells that operate as a first line of defense in the disease’s initial stages
  • Serology test – A serology test can show an increase in antibodies, but the test can’t discern between increases caused by a viral infection and antibodies from a vaccination.
  • Radiograph (x-ray) – Your vet might use x-rays, but these are only generally used to determine if a dog has contracted pneumonia.
  • CT and MRI scans – These imaging scans can help the vet see if your dog has any lesions on his brain.

While positive results can confirm that your pup is suffering from an infection, your dog may still be infected even with negative test results.

Treatment for Canine Distemper

Sadly, there is no cure for canine distemper. Once distemper has been diagnosed, care aims at supporting your dog’s health and relieving individual symptoms. The three main goals for treatment include:

  • Preventing secondary infections
  • Controlling any vomiting, diarrhea, and neurological symptoms
  • Preventing dehydration and rehydrating your pup via intravenous fluids

Your dog will likely be hospitalized and separated from other dogs to lower the risk of spreading the infection. Your vet can prescribe antibiotics to treat the symptoms of a sec