Canine distemper

Canine distemper is a contagious, incurable and often fatal disease that affects the respiratory, gastrointestinal, and central nervous systems. Distemper is caused by the canine distemper virus (CDV).

Widespread vaccination programs have dramatically reduced its incidence.

Canine distemper virus occurs among domestic dogs and is fairly common in wildlife. The development of a vaccine in the early 1960s led to a dramatic reduction in the number of infected domestic dogs. It tends to occur now only as sporadic outbreaks.

The condition generally affects puppies between 3 and 6 months of age. Unvaccinated older dogs are also highly susceptible to infection and disease.

Transmission

Canine distemper virus spreads through the air and through contact with infected bodily fluids, including food and water contaminated with these fluids

Symptoms

Early symptoms include fever, loss of appetite, and mild eye inflammation that may only last a day or two. Symptoms become more serious and noticeable as the disease progresses.

The initial clinical sign is a high temperature which usually reaches its highest at 3 to 6 days after infection. Dogs may experience eye and nose discharge, depression, and loss of appetite (anorexia). After the fever, symptoms vary considerably, depending on the strain of the virus and the dog's immune system status.

  • Conjunctivitis (discharge from the eye)
  • Diarrhoea
  • High temperature
  • Pneumonia (cough, laboured breathing)
  • Rhinitis (runny nose)
  • Vomiting

These symptoms are often made worse by a secondary bacterial infection. Dogs invariably develop encephalomyelitis (inflammation of the brain and spinal cord), Most dogs that die from distemper, die from neurological complications such as the following:

  • Ataxia (muscle incoordination)
  • Depression
  • Hyperesthesia (increased sensitivity to sensory stimuli, such as pain or touch)
  • Muscle twitching or spasm
  • Paralysis
  • partial or incomplete paralysis
  • Seizures that can affect any part of the body (One type of seizure that affects the head, and is unique to distemper, is sometimes referred to as a "chewing gum fit" because the dog appears to be chewing gum.)

Eye symptoms:

  • Inflammation of the eye
  • Lesions on the retina (the innermost layer of the eye)
  • Optic neuritis (inflammation of the optic nerve which leads to blindness)

Two relatively minor conditions that often become chronic, even in dogs that recover are:

  • Enamel hypoplasia (unenameled teeth that erode quickly in puppies whose permanent teeth haven't erupted yet—the virus kills all the cells that make teeth enamel)
  • Hyperkeratosis (hardening of the foot pads and nose)

Treatment and prevention

There is no specific treatment for canine distemper. Treatment is generally supportive, using antibiotics for secondary bacterial infections, intravenous fluids, and nutritional supplements. The prognosis is poor.

The virus is destroyed in the environment by routine cleaning with disinfectants, detergents, or drying. It does not survive in the environment for more than a few hours at room temperature (20-25 °C), but can survive for a few weeks at temperatures slightly above freezing.

Vaccination of puppies and adult dogs is a very effective way of preventing the disease.