Canine distemper virus (CDV) is an airborne type and highly contagious viral disease that is often fatal and can affect the respiratory, urogenital, gastrointestinal, optic nerves, and central nervous system.

Canine distemper is closely related to measles in humans. So if a person is vaccinated and immune to measles then they will also be immune to dog distemper. However, even if a person were to possibly get infected with canine distemper virus, they would likely show no signs or symptoms at all. No cases of humans becoming infected with distemper have been reported though. 

Measles only has humans as its natural host but canine distemper virus can infect many carnivorous and weasel-like animals such as lion, ferrets, foxes, wolves, coyotes, skunks, wild hogs, badgers, raccoons, pandas etc. Dog distemper cannot affect or pass on to cats unlike other dog problems like skin irritations, mange, fleas, etc. Cat distemper is known as feline panleukopenia which is characterized by loss of appetite, high fever, lethargy, vomiting, severe diarrhea, depression, and nasal discharge.

As opposed to older dogs, puppies between 3-6 month of age are most susceptible to this virus and may suffer from more serious conditions such as inflammatory illness of the lung (pneumonia) and acute inflammation of the brain (encephalitis). Around 15 percent of canine inflammatory central nervous system diseases are caused by canine distemper virus (CDV).

Nursing puppies have lower chance of CDV infection because a certain degree of immunity is passed down to puppies by colostrum-milk. But this only happens if colostrum-milk was given during the first 8-24 hours after birth. Older dogs have little or no susceptibility to CDV virus because of the immunity built up over the years. There has been one case of a 7-8 years old dog being infected with distemper but it’s still a rarity.

Seasons also have direct effects on the spread of dog distemper virus. Summer season and warm weather can force CDV to become dormant and lower its prevalence rate. However, CDV can be most virulent during early spring, fall and winter season. Dog distemper incubation period ranges from 3-21 days in approximation and may be longer depending on other factors such as seasons, temperature, immunity etc.

Dog distemper symptoms

Early signs and symptoms of dog distemper

  • fever
  • loss of appetite (anorexia)
  • mild eye inflammation (usually last two day)
  • temperature rise to above 103 degree Fahrenheit
  • depression
  • nasal discharge
  • discharge from eye (conjunctivitis)

Dogs will have following symptoms when CDV affects the intestinal tract.

  • vomiting
  • diarrhea
  • loss of appetite
  • suddenly weak
  • lethargy

Dogs will have following symptoms when CDV affects the lungs and upper respiratory tract.

  • coughing
  • sneezing
  • vomiting
  • green discharge from nostril
  • discharge eye (conjunctivitis)
  • diarrhea
  • cough and labored breathing (pneumonia)
  • runny nose (rhinitis)
  • fever (usually unnoticed)

Dogs will have following symptoms when CDV affects the brain and spinal cord (encephalomyelitis), secondary bacterial infections.

  • seizures
  • muscle incoordination (ataxia)
  • uncontrollable muscle twitch (myoclonus)
  • hard pad disease
  • depression
  • abnormal increase in sensitivity to stimuli of the senses including hearing, tasting, feeling sense (hyperesthesia)
  • partial or incomplete paralysis (paresis)
  • deterioration of mental abilities


  • Dr. Winnie, Veterinarian

    Dr. Winnie earned a Master in Biology from St Georges University, and graduated from the University of Pretoria's Veterinary School. She is a full-time Veterinarian specializing in internal medicine for companion animals.