Canine distemper is a viral disease that affects dogs worldwide. The disease is most common in young, unvaccinated dogs. Initially, fever and ocular and nasal discharge will be seen, but this will progress to include clinical signs involving the gastrointestinal tract, respiratory tract and central nervous system. The mortality rate can reach 50 percent.
Common name: Distemper, Hard pad disease.
Scientific name: Canine distemper virus.
Canine distemper can affect dogs of any age but is more common in young dogs 3 to 6 months old or older dogs with a compromised immune system. Poorly vaccinated or unvaccinated dogs of any age can develop distemper. Some breeds may be at higher risk than others, but this has not been proven.
Not well established. In a well-vaccinated population, incidence may be fairly low. On the other hand, in a poorly vaccinated population, it may be fairly high.
Canine distemper affects dogs worldwide.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
Vomiting, diarrhea, bloody diarrhea, anorexia, adipsia (not drinking), Oculonasal discharge, dyspnea (trouble breathing), coughing, Myoclonus (repetitive contraction of muscles), seizures (chewing gum‚ seizures), depression, ataxia (drunkenness), paresis (weakness of the hind legs), paralysis, muscle tremors, hyperesthesia (increased sensitivity to stimuli), blindness, Hyperkeratosis (thickening) of nose and footpads, Enamel hypoplasia (malformation) of teeth (neonates only).
Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Secondary bacterial infection of the respiratory tract (pneumonia), Secondary bacterial infection of the gastrointestinal tract (increased severity of vomiting, diarrhea and anorexia).
Cause (scientific, common term)
Canine distemper virus (a morbillivirus in the Paramyxovirdae family).
Organ systems affected (most to least affected)
Gastrointestinal tract, Respiratory tract, Central nervous system, Integument, Tooth enamel.
Complete blood count and chemistry profile, Thoracic radiographs, PCR, immunohistochemistry, virus isolation, Fluorescent antibody on biopsy or postmortem samples, Cerebral spinal fluid tap, C. Differential Diagnosesm Gastrointestinal signs, Canine parvovirus, Canine coronavirus, Inflammatory bowel disease, Pancreatitis, Indiscriminate eating habits, Respiratory signs, Infectious tracheobranchitis , Other viral pneumonias, Bacterial pneumonia, CNS, Encephalitis, Metaldehyde poisoning, Strychnine poisoning.
Canine distemper is a serious disease that affects dogs worldwide. The disease is caused by the canine distemper virus. While it can affect dogs of any age, it is most commonly seen in young, unvaccinated dogs between the ages of 3 and 6 months and older dogs with compromising health conditions. It is possible some breeds are more prone to distemper than others, but this has not been proven. Distemper is a serious disease due to its high mortality rate.
Distemper is transmitted by nasal discharge and saliva when dogs are in close contact with one another. Initially, an infected dog has a fever, eye and nose discharge, vomiting, and diarrhea. Symptoms frequently progress to include coughing, trouble breathing, and a decrease in appetite and drinking. Complications such as secondary bacterial infections and dehydration are common.
Dogs surviving the initial phase may develop neurological signs days to weeks later. Neurological signs can include a lack of coordination, increased sensitivity to stimuli, paralysis, blindness, depression, muscle tremors and seizures. Chewing gum‚ seizures are frequently described in dogs with distemper. If a puppy is affected as a neonate, the virus can damage the development of the tooth enamel, resulting in malformed teeth. In some cases, a thickening of the footpads and nose may be seen.
A dog diagnosed with or suspected of having distemper should be isolated from all other dogs until all clinical signs resolve. Dogs rarely recover from distemper on their own, so veterinary care is essential. If a veterinarian has determined a dog is stable enough to return home, it is important to monitor the dog's appetite and water consumption. The dog must continue to receive all medications prescribed by the veterinarian and be kept in a clean and warm environment.
Diagnosis is commonly made by history, physical exam and symptoms exhibited by the dog. Laboratory test such as complete blood cell count, chemistry profile, biopsies, X-rays, and bacterial cultures and sensitivities may be performed to aid in diagnosis. There is no specific treatment available for distemper, so treatment largely consists of supportive care. Treatments may include intravenous fluids, antibiotics, oxygen, and medications to control vomiting and seizures.
Veterinarians are also important in the prevention of distemper. They will decide the best age to start vaccinations for a puppy and when a dog is healthy enough to receive its vaccine.
If it is suspected that a dog may have distemper, then it must be isolated from other dogs and veterinary care must be sought immediately. Since there are no specific treatments for distemper, the key is prevention. Vaccines are readily available and are the best way to prevent the disease. The immunity puppies receive from their mother begins to wane around 6 to 12 weeks of age, so it is important to start vaccinations at this time. Immunity is not lifelong, so a dog must continue to receive vaccinations on a routine basis to maintain its immunity.
The outcome is dependent on many factors, including the age of the dog, immune status and the strain of the virus the dog is infected with. Mortality rate is commonly around 50 percent, but with veterinary care, this rate may be lower. If neurological signs are seen, the prognosis is typically poor.
Greene, Craig E and Max J Appel. Canine Distemper. Infectious Diseases of the Dog and Cat. Philadelphia: Saunders, 1998; 9-21.
Taylor, Susan M. Canine Distemper. Fathman, Elizabeth, ed. Small Animal Internal Medicine. St. Louis: Mosby, 2003; 1015-1016.
Mellema, Matthew S. Canine Distemper. King, Lesley G, ed. Textbook of Respiratory Disease in Dogs and Cats. Philadelphia: Saunders, 2004; 435-437.
Kirsten Waratuke, DVM
Steven Hansen, DVM, MS, MBA, DABVT, DABT
Copyright 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)