In the days following infection, the first sign will be a fever which may only last a few days.
This is then followed by a second fever which lasts longer and is accompanied by other signs. Many dogs will have partial immunity, either from their mother, or from a lapsed booster. They might only show slight malaise, perhaps with runny eyes and nose and a cough. It is these dogs that are most likely to spread the full disease to unprotected dogs in the community.
Various forms of the disease exist:
Respiratory form: characterised by difficulty in breathing, nasal discharge, sneezing and coughing - Secondary bacterial infection is possible. The digestive form is typified by vomiting and diarrhoea.
Cutaneous form: typified by a thickening of the skin on the nose and pads (hence the old name of “hardpad”). This form may be associated with nervous signs, which consist of fits or gradual twitching of the muscles and paralysis of the limbs (“chorea”). This may be coupled with a characteristic half-cough caused by nerve damage. In this form, the initial disease has often passed unnoticed.
Ocular form: Signs of conjunctivitis (runny eyes) and other less obvious ocular changes
Distemper is a disease caused by the canine distemper virus. It affects dogs primarily, but in Europe other animals, such as foxes and ferrets can be affected. The virus is closely related to the measles virus.
It is primarily spread by contact with affected dogs. The virus is present in eye and nasal discharges that readily form aerosol droplets. Infected dogs may shed the virus for several months. Although the virus is relatively unstable outside the dog, it can be carried on the clothing and subsequently infect any unprotected dogs. Spread is very rapid in any group of dogs, especially in kennels and at dog shows, hence the necessity to vaccinate dogs. Like canine viral hepatitis, introduction of an infected puppy is the commonest source of an outbreak.
Puppies from an unvaccinated mother, unvaccinated dogs and the immunosuppressed are most at risk. The infection begins by attacking the respiratory system, but in time many organs may become infected, including the brain.
Although Canine Distemper is difficult to diagnose definitively, a presumptive diagnosis can usually be made using a combination of clinical signs and some diagnostic tests. Certain samples from the dog, including blood tests, spinal fluid, secretions from the nose or tissue samples can be taken to help with diagnosis. However, there is no test that is fully reliable, and absolute confirmation may be impossible.
The causative virus cannot be treated. Any secondary bacterial infections can usually be treated and supportive treatment will also be necessary. Treatment could therefore include:
Antibiotic treatment to control any bacterial infections, if present.
Medication to control symptoms, such as diarrhoea, vomiting, coughing and fits.
Nursing care to remove soiling, eye/nose discharges etc.
Support to encourage eating and drinking.
Infected and in-contact dogs MUST be isolated from other susceptible dogs and strict hygiene precautions are needed to prevent spread (change of clothing/disinfectants). Unfortunately treatment is not always successful, and the prognosis is especially poor for dogs that show neurological signs.
Prevention is by vaccination. The distemper component should always be included in the primary vaccination course given to puppies, and is often included in routine booster vaccinations. Based on your pet’s specific situation, your veterinary surgeon will decide the best vaccination protocol to meet your pet’s needs. An up-to-date vaccination is obligatory before going to dog shows and many kennels.
In the event of an outbreak of disease, strict isolation and hygiene precautions must be instituted.