Distemper in Dogs and Puppies

Distemper in dogs is a highly contagious and often fatal disease that affects multiple body systems. Though its prevalence has diminished greatly due to effective vaccinations, distemper cases and outbreaks are still seen sporadically. Distemper often strikes puppies exposed to the spreadable virus in shelters, kennels, or other environments where there may already be infected and unvaccinated animals. Regardless of your dog's age, be especially vigilant about symptoms, such as eye discharge or nervous system problems. Here's what pet parents should know about distemper in dogs and puppies.

What Is Distemper in Dogs?

Canine distemper is a virus similar to human measles that can affect the gastrointestinal tract, respiratory tract, and nervous system, including the brain and spinal cord. The virus can infect a dog of any age but is especially risky to puppies if they are not fully vaccinated. It also can infect several other species including ferrets and wild animals such as coyotes, foxes, wolves, skunks, and raccoons.

Incubation is the time it takes from exposure to the development of signs of disease. Within a few days following infection, the virus spreads throughout the body. Whether or not the infected pup survives depends on the effectiveness of the dog's immune system and the availability of supportive treatment. About 50 percent of adult dogs and 80 percent of puppies that develop this disease will die, especially if left untreated.

Symptoms of Distemper in Puppies

Canine distemper causes symptoms in multiple body systems, including the gastrointestinal tract, respiratory tract, skin, and nervous system. The appearance of symptoms and the course of distemper can be variable, ranging from very mild illness to fatal disease. Early symptoms may look like an ordinary cold. Other symptoms that develop may be more subtle, such as thicker paw skin, or more obvious, such as seizures. Neurological symptoms of distemper may develop later in the disease (sometimes even after several weeks) or never at all.

Here are the many symptoms of distemper in dogs and puppies:

Discharge From Nose and Eyes

Early on in the disease, puppies may have what appears to be a runny nose. The fluid is often a characteristic thick white to yellow discharge from its nose and eyes that looks like a run-of-the-mill cold symptom. Along with eye discharge, a dog with distemper could experience eye inflammation. The eyes appear swollen or reddened from the irritation and discomfort of the discharge.

Fever

A fever often occurs three to six days after infection. This is because the virus destroys white blood cells resulting in a fever that may last a day or two. The fever may go unnoticed and will usually subside, but a second fever can occur a few days later along with other symptoms.

Gastrointestinal Issues

The virus can affect the cells lining the stomach and intestinal tract and may appear in the dog's feces. Specific symptoms include vomiting, diarrhea, and loss of appetite.

Lethargy

Your dog will likely feel increasingly lethargic as the virus progresses due to the multiple symptoms the dog is experiencing.

Hardening of Skin

A tough or crusty coating may form on the dog's footpads and/or nose (which is why distemper is sometimes called "hard pad" disease). The skin on the nose and paw pads may thicken and crack, which is called hyperkeratosis.

Labored Breathing and Coughing

Infection of the respiratory system can cause coughing and labored breathing. If a dog has recently been in a shelter or kennel, these signs should be investigated rather than assuming it's the common kennel cough. These symptoms could be the onset of pneumonia, which is associated with distemper.

Central Nervous System Issues

When the distemper virus has reached the puppy's nervous system, the dog will display symptoms such as involuntary muscle twitching, behavioral changes, head tilt, involuntary eye movements, weakness, paralysis, and poor coordination. Seizures will begin to occur, which may include full-body convulsions. A localized seizure unique to distemper may look like the dog is chewing gum. The seizures will become more frequent as the disease progresses in the dog's system.

Increased Sensitivities

In advanced distemper cases, a dog may have an increased sensitivity to touch or pain. In addition, a dog may experience light sensitivity due to eye discomfort.

What Causes Distemper in Dogs and Puppies?

Distemper in dogs is caused by the canine distemper virus. This highly contagious and often fatal virus is shed in the saliva, respiratory secretions, urine, and feces, and treated dogs can shed the virus for several weeks after recovery.

Distemper typically spreads between animals as viruses spread among people⁠—by sneezing and coughing. Dogs usually become infected by direct contact with virus particles from the secretions of other infected animals (generally via inhalation). Indirect transmission, carried on dishes or other objects, is uncommon because the virus does not survive long in the environment.

Dogs adopted from stressful places like animal shelters, rescues, and pet stores are the most likely to contract the disease, especially those younger than four months of age. Dogs and puppies can appear healthy during the incubation period—even after vaccination—but may become sick once in their new home.

Puppies under four months of age (before vaccinations are fully protective) and unvaccinated dogs are most at risk. Because canine distemper also occurs in wild animals, contact with wild animals may contribute to the spread of distemper in domestic dogs.

How Vets Diagnose Distemper in Puppies

Because signs are variable and may take time to appear, and secondary infections are common, the diagnosis of distemper can be complicated. Additionally, other infections can show signs similar to distemper.

Unvaccinated puppies from shelters or pet stores may be misdiagnosed with common kennel cough instead of distemper. Obvious clinical symptoms will usually alert a veterinarian to the presence of distemper. However, diagnostic laboratory tests, including blood, tissue, and nasal/eye swab tests can help confirm the diagnosis (and some may be done to rule out other infections).

How to Treat Distemper in Dogs and Puppies

There is no cure for the distemper virus. Dogs and puppies with severe symptoms usually die within a few weeks unless hospitalized and given supportive care. Even with treatment, distemper can be fatal.

Treatment involves managing the various symptoms and secondary infections, and owners can provide some nursing care at home. However, no single treatment is specific or always effective. It may take ongoing therapy for several weeks to conquer the disease. Treatments may include the following:

• Fluids to combat dehydration
• Medication to reduce vomiting
• Antibiotics, and other medications to treat pneumonia and secondary infections
• Anticonvulsants to treat seizures

Dogs with suspected distemper should be isolated from other dogs, and the other dogs should be vaccinated if they are not current on immunizations. The canine distemper virus does not typically survive long outside the body, so thorough home disinfection is not as critical as with some other viruses; routine cleaning with any disinfectant should be sufficient. Check with your vet for recommendations on waiting times to introduce a new dog or puppy to a household with a dog that has been diagnosed with distemper.

Prognosis for Dogs With Distemper

The prognosis depends on factors such as the timing of treatment and the dog's immune system. Each dog responds differently to treatment; for some, the symptoms get better temporarily but worsen before recovery. Others show no improvement despite aggressive treatment. Your veterinarian can guide you when making the heartbreaking decision to euthanize a sick pet.

Dogs that survive infection during puppyhood may suffer enamel hypoplasia—poorly developed tooth enamel that's pitted and discolored. Even with recovery, some neurological effects, such as seizures, may persist in your dog.

How to Prevent Distemper

By far, the simplest and most effective way to prevent distemper is to adhere to the prescribed vaccination schedule for your puppy and continue to vaccinate adult dogs. The distemper vaccine is part of the DHPP combination vaccine.

Until puppies have received all the vaccinations in the series (around 16 weeks of age) it is prudent to be careful about exposing them to unknown dogs such as at dog parks to avoid exposure to the virus as much as possible. It's also important to prevent contact with wildlife.

Is Distemper Contagious to Other Animals?

Yes, distemper is highly contagious. A recovering dog will shed the virus for weeks or months, which can still infect other healthy dogs. Sick or recovering dogs must be quarantined away from healthy animals. The virus can be killed using a disinfectant such as household bleach on surfaces and objects.