Distemper in dogs, which is highly contagious, is a sometimes fatal disease that is seen in canines worldwide. Though its prevalence has diminished greatly due to vaccination, distemper cases and outbreaks are still seen sporadically.
Canine distemper is caused by the canine distemper virus. This virus can also infect several other species including ferrets and wild animals such as coyotes, foxes, wolves, skunks, and raccoons.
Animals usually become infected by direct contact with virus particles from the secretions of other infected animals (generally via inhalation). Indirect transmission (i.e., carried on dishes or other objects) is not common because the virus does not survive for long in the environment. The virus can be shed by dogs for several weeks after recovery.
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 to domestic dogs.
Signs and Symptoms of Distemper
Canine distemper causes symptoms in multiple body systems, including the gastrointestinal tract, respiratory tract, and the brain and spinal cord. The appearance of symptoms and course of distemper can be variable, ranging from very mild illness to fatal disease.
Any of the following can be seen:
- Fever (often one episode a few days after infection that may not be noticed, followed by a second episode a few days later when the other symptoms begin to show up)
- Discharge from the eyes and nose
- Loss of appetite
- Vomiting and diarrhea
- Labored breathing
- Hardening of footpads and nose (distemper has sometimes been called hardpad disease)
- Inflammation of various parts of the eye
- Secondary bacterial infections
- Neurological symptoms are variable
Neurological symptoms of distemper may not develop at all or develop later in the disease (sometimes even after several weeks). Neurological symptoms of distemper may include any of the following:
- Muscle twitching
- Weakness or paralysis
- Seizures (of any part of the body, but seizures that look as if the dog is chewing gum are unique to distemper)
- Uncoordinated movements
- Increased sensitivity to touch or pain
Diagnosis of Distemper
Diagnosis is based primarily on the the history and clinical signs. Because signs are variable and may take time to appear, and secondary infections are common, diagnosis can be complicated. Additionally, other infections can produce similar signs to distemper. A variety of laboratory tests can help confirm the diagnosis (and some may be done to rule out other infections).
Treatment of Distemper
There is no treatment specific to the distemper virus, so treatment involves managing the various symptoms and secondary infections. Even with treatment, distemper can be fatal. Treatment depends on the symptoms shown, and may include fluids to combat dehydration, medication to reduce vomiting, antibiotics and other medications to treat pneumonia, antibiotics for secondary infections, and anticonvulsants to treat seizures.
Neurological symptoms may get progressively worse and not respond to treatment, and even with recovery some neurological effects may persist.
Prevention of Distemper
Vaccination is effective at preventing distemper. Puppies are typically vaccinated starting at 6 weeks of age and at regular intervals (every 2-4 weeks) until they are 14-16 weeks old (as with other vaccines, presence of antibodies received from the mother can interfere with vaccines so a puppy is not considered fully protected until the final vaccine in the series has been given). Vaccination should be repeated a year later, then at regular intervals. Your vet will discuss an appropriate vaccination schedule for your dog based on your dog's history and risk factors.
Until puppies have received all the vaccinations in the series (at 14-16 weeks) it is prudent to be careful about exposing them to unknown dogs (e.g., at dog parks) to avoid exposure to the virus as much as possible.
Home Care for a Dog with Distemper
Dogs suspected of having distemper should be isolated from other dogs. Other dogs in a household from which a dog has been diagnosed with distemper should be vaccinated if they are not currently vaccinated. The canine distemper virus does not typically survive long outside the body so thorough disinfection of the home 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 puppy to a household with a dog that has been diagnosed with distemper.