Dogs get distemper by catching a contagious virus from other infected dogs or wildlife, mainly through respiratory droplets and body fluids. It spreads very much like a bad “cold” in dogs, especially in unvaccinated puppies and dogs in high-contact places such as shelters or kennels.

What distemper is

Canine distemper is a serious viral disease caused by the canine distemper virus, a paramyxovirus related to the viruses that cause measles and mumps in humans. It attacks several body systems at once, including the lungs, gut, skin, and brain, which is why signs can look so varied and severe.

Main ways dogs get distemper

Dogs usually become infected when virus particles from a sick animal enter through the nose or mouth. Common routes include:

  • Breathing in droplets when an infected dog or wild animal coughs, sneezes, or barks nearby.
  • Direct contact with infected saliva, nasal discharge, urine, blood, or feces, for example from licking or sharing toys.
  • Using contaminated bowls, bedding, or other objects (the virus can survive long enough on surfaces to infect another dog).
  • Puppies getting the virus across the placenta from an infected mother before they are born.

Once inside the body, the virus first multiplies in lymph nodes in the chest, then spreads via the bloodstream to the respiratory, digestive, urinary, and nervous systems. This body‑wide spread is what makes distemper so dangerous and often fatal in unvaccinated animals.

Which dogs are most at risk

Certain dogs are much more likely to catch distemper if exposed.

  • Puppies between 3–6 months old, especially if their vaccinations are incomplete or delayed.
  • Unvaccinated or under‑vaccinated adult dogs, including rescues with unknown vaccine history.
  • Dogs in crowded environments like shelters, kennels, puppy mills, and poorly run breeding facilities.
  • Dogs that roam or interact with wildlife such as raccoons, foxes, or skunks, which can carry and shed the virus.

Areas or communities with low vaccination rates tend to see more frequent and larger outbreaks of distemper.

How to lower your dog’s risk

The good news is that distemper is highly preventable with the right steps.

  • Keep core vaccinations (DAPP or DHPP) up to date; puppies need a series of shots and timely boosters.
  • Avoid dog parks, daycare, or boarding until your puppy’s vaccine series is complete and your vet says it is safe.
  • Isolate sick dogs from others and disinfect bowls, bedding, and surfaces if distemper or similar illness is suspected.
  • In rescue or shelter situations, follow strict intake vaccines, quarantine, and sanitation protocols to stop spread.

If a dog shows signs such as fever, eye or nose discharge, coughing, vomiting, diarrhea, or twitching and seizures—especially with poor vaccination history—urgent veterinary care is critical. Early supportive treatment improves the chances of survival and can sometimes limit long‑term neurological damage.

Information gathered from public forums or data available on the internet and portrayed here.