# How Do Dogs Get Distemper and How Long Does It Last? Dogs get distemper most often by breathing in tiny droplets that an infected dog or wild animal coughed, sneezed, or barked into the air [1]. The virus can also pass through direct contact with saliva, urine, or feces [1]. So the short answer to distemper in dogs how do they get it is simple: close contact with an infected animal, usually through the air. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Distemper spreads mainly through airborne droplets from an infected animal, and also through saliva, urine, or feces [1]. - Infected dogs can be contagious several days before they look sick, and even mildly affected dogs can shed large amounts of virus [1]. - Some dogs shed virus particles for several months after infection [2]. - The virus does not survive long outside a host, so most transmission happens through close contact, not through contaminated ground [2]. - There is no cure that kills the virus. Treatment is supportive care, and the outlook depends heavily on whether neurologic signs appear [2]. ## What Distemper Actually Is Canine distemper is a highly infectious viral disease that affects dogs worldwide [2]. The cause is canine distemper virus, a paramyxovirus closely related to the viruses that cause measles and rinderpest [2]. It is a fragile, enveloped, single-stranded RNA virus, which means it breaks down fairly quickly outside an animal's body [2]. That fragility matters for owners. Distemper is not the kind of virus that lingers for weeks on a sidewalk or in a yard. It spreads when a susceptible dog is close enough to an infected animal to breathe in infectious droplets [2][1]. Distemper is not only a dog disease. It also infects other carnivores, including ferrets, raccoons, skunks, and foxes [1]. That wildlife connection is one reason the virus keeps circulating even in areas where most pet dogs are vaccinated. ## Signs Owners Notice Early distemper can be easy to miss because the signs look like many other common illnesses [1]. A dog may run a fever, seem tired, go off food, and develop a runny nose or diarrhea [2]. Respiratory signs can include nasal discharge and pneumonia, and gastrointestinal signs can include diarrhea [2]. The pattern that worries veterinarians is what comes next. Some dogs develop neurologic signs such as muscle twitching or focal or generalized seizures, and these can be delayed, appearing after the early illness seems to be improving [2]. That delay is one reason distemper has such an unpredictable reputation. If your dog has a runny nose, a cough, or a bout of diarrhea, distemper is not the first thing most veterinarians suspect. But if your dog is unvaccinated, recently around wildlife, or has a combination of respiratory, stomach, and neurologic signs, distemper moves up the list quickly. ## Distemper in Dogs: How Do They Get It and Who Is at Risk? ### How the virus moves between animals The main route is aerosol droplets from an infected animal [2]. When a sick dog coughs, sneezes, or barks near a healthy dog, virus particles can land in the healthy dog's nose, mouth, or eyes [1]. Direct contact with infected dogs or their bodily fluids, such as saliva, urine, or feces, is another route [1]. Infected dogs become contagious to other dogs several days before they show any signs of illness [1]. That silent window is why outbreaks can spread through a kennel, shelter, or neighborhood before anyone realizes a dog is sick. Even mildly affected dogs can look well while shedding significant amounts of the virus [1]. ### How long dogs shed the virus Shedding is the period when an infected dog can pass the virus to others. Some infected dogs may shed virus particles for several months [2]. That is a long time, and it is the reason veterinarians are cautious about declaring a dog non-infectious based on how the dog looks. If you need to know whether a recovered dog is still contagious, testing can help. PCR or virus isolation tests can confirm an infection and help determine whether recovered dogs are likely to still be infectious to other dogs [1]. ### Wildlife and the environment Wild carnivores act as a reservoir. Canine distemper virus affects both domestic and wild carnivores and is associated with a high mortality rate, and the virus can cross species barriers to infect a wide range of mammals [3]. Red foxes, raccoons, skunks, and ferrets are all susceptible [1][3]. The virus is relatively unstable outside the host, so it does not persist in the environment the way some tougher viruses do [2]. In practice, that means the risk usually comes from an infected animal, not from a patch of grass. ### Risk factors you can actually change Low vaccination rates and high dog populations make spread more likely in a community [1]. Puppies, unvaccinated dogs, and dogs with unknown vaccine history are the ones most likely to get sick. Dogs that spend time in shelters, boarding kennels, or areas with heavy wildlife traffic face more exposure. If you are comparing distemper to other serious puppy diseases, our guide on [How Does A Dog Get Parvo](/knowledge/veterinary-medicine/clinical-methods/how-does-a-dog-get-parvo) covers a virus with a very different survival strategy in the environment. ## How Distemper Is Diagnosed Diagnosis starts with the history and physical exam. Your veterinarian will ask about vaccination status, recent contact with other dogs, wildlife exposure, and the timeline of signs. Confirmation comes from laboratory testing. Diagnosis is made by recognizing the clinical signs along with confirmation through antibody assays or reverse transcriptase PCR [2]. A PCR test detects the virus's genetic material, and a quantitative PCR is considered the current test of choice [1]. Your veterinarian chooses which test to run based on how long your dog has been sick and which signs are present. No single test is perfect at every stage, so results are read alongside the exam findings. ## Treatment Options There is no antiviral drug that clears distemper. Treatment is generally supportive, and the prognosis varies with the severity of the neurologic signs [2]. Supportive care can include fluids for dehydration, medications to control nausea or diarrhea, nutritional support, and treatment for secondary bacterial infections such as pneumonia. Seizures and other neurologic signs may need their own management. Your veterinarian calculates every dose from your dog's weight and health, so never give human medications or leftover pet medications on your own. Hospitalization is common for dogs who are dehydrated, not eating, or struggling to breathe. Some dogs with mild signs can be managed at home with close veterinary follow-up. Either way, isolation from other dogs is part of the plan. ## Recovery, Outlook, and Long-Term Management ### How long distemper lasts This is the question owners ask most, and the honest answer is that it varies. The contagious period starts several days before signs appear, and signs can take from less than a week up to six weeks to show after exposure [1]. Some infected dogs may shed virus particles for several months [2]. For a dog who survives the acute illness, the visible recovery often takes weeks, not days. Neurologic signs can appear later, even after the respiratory and stomach signs have settled [2]. That means the "how long does it last" answer depends on whether the nervous system is involved. ### What recovery looks like Some dogs recover fully. Others survive with lasting neurologic problems, including twitching or seizures [2]. The prognosis varies with the severity of the neurologic signs, which is why veterinarians are cautious about giving a firm outlook early in the illness [2]. If your dog recovers, plan on keeping them away from other dogs until your veterinarian confirms they are no longer likely to be infectious. PCR or virus isolation testing can help answer that question [1]. ### Isolation at home Isolation means no dog parks, no walks where other dogs pass, no boarding, and no contact with unvaccinated dogs in the household. Since shedding can continue for months in some dogs, follow your veterinarian's timeline instead of guessing based on how your dog looks [2]. Dispose of soiled bedding and clean food and water bowls separately. Wash your hands after handling your dog. The virus is fragile outside the host, but basic hygiene still lowers the risk to other animals in the home [2]. ### A quick reference table | Question | Short answer | |---|---| | Main way dogs get it | Airborne droplets from an infected animal [2][1] | | Other routes | Saliva, urine, feces, direct contact [1] | | When contagious | Several days before signs appear [1] | | How long shedding can last | Up to several months in some dogs [2] | | Time from exposure to signs | Less than a week up to six weeks [1] | | Is there a cure | No, treatment is supportive [2] | | What drives prognosis | Severity of neurologic signs [2] | ## Prevention Vaccination is the foundation. A vaccine is available and is generally effective [2]. Puppies typically start a series and then move to regular boosters, and your veterinarian will set the schedule based on your dog's age and risk. Reducing exposure matters too. Keep unvaccinated puppies away from unknown dogs and wildlife areas. If you foster or rescue dogs with unknown vaccine history, quarantine them away from your own dogs until a veterinarian clears them. Because wildlife can carry the virus, avoid leaving food out that attracts raccoons, foxes, or skunks [1][3]. If you see a wild animal acting strangely, keep your dog away and contact local animal control. For owners tracking normal canine cycles and other timing questions, our articles on [How Long Does A Dog Period Last](/knowledge/veterinary-medicine/clinical-methods/how-long-does-a-dog-period-last) and [Dog Reverse Sneezing How Long Does It Last](/knowledge/veterinary-medicine/clinical-methods/dog-reverse-sneezing-how-long-does-it-last) cover common "how long" concerns that are far less serious than distemper. ## Limitations and When to Contact a Veterinarian No article can tell you what is happening with your individual dog. Distemper looks different in every case, and only a veterinarian who examines your dog can diagnose and treat it. Contact your veterinarian the same day if your dog has a new cough, runny nose, vomiting, or diarrhea, especially if vaccination status is unclear or there was recent wildlife exposure. Go to an emergency clinic now if your dog is having a seizure, twitching uncontrollably, struggling to breathe, collapsing, or cannot keep water down. Schedule a routine visit if you need to update vaccines, if you have a new puppy, or if you are bringing a rescue dog with unknown history into a home with other dogs. ## Frequently Asked Questions ### Can a dog get distemper from sniffing the ground where a sick dog walked? It is possible but uncommon. The virus is fragile and relatively unstable outside the host, so it does not survive long in the environment [2]. Close contact with an infected animal is the far more likely route [1]. ### Can a vaccinated dog still get distemper? Yes, though it is uncommon. Vaccination is generally effective, but no vaccine prevents every infection [2]. Vaccinated dogs that do get sick often have milder signs, which is one reason keeping boosters current matters. ### Is distemper contagious to people or cats? People do not get canine distemper. Cats have their own separate distemper-like virus, and canine distemper is not the same disease. The virus does infect other carnivores, including ferrets, raccoons, skunks, and foxes [1]. ### How soon after exposure will my dog show signs? Signs can appear from less than a week up to six weeks after exposure [1]. Because the range is wide, your veterinarian may recommend monitoring or testing instead of assuming your dog is safe after a few days. ### Can my dog spread distemper after they seem better? Yes, that is possible. Some infected dogs may shed virus particles for several months [2]. Ask your veterinarian when your dog can safely be around other dogs again, and expect testing to be part of that decision [1]. ## Related Articles - [How Does A Dog Get Parvo](/knowledge/veterinary-medicine/clinical-methods/how-does-a-dog-get-parvo) - [How Long Does A Dog Period Last](/knowledge/veterinary-medicine/clinical-methods/how-long-does-a-dog-period-last) - [How Long Does A Dogs Heat Last](/knowledge/veterinary-medicine/clinical-methods/how-long-does-a-dogs-heat-last) - [Dog Reverse Sneezing How Long Does It Last](/knowledge/veterinary-medicine/clinical-methods/dog-reverse-sneezing-how-long-does-it-last) - [How Long Do Dog Periods Last](/knowledge/veterinary-medicine/clinical-methods/how-long-do-dog-periods-last) - [How Long Do Dogs Live](/knowledge/veterinary-medicine/clinical-methods/how-long-do-dogs-live) - [Distemper Incubation Period in Dogs: What to Expect](/knowledge/veterinary-medicine/parasitic-diseases/distemper-incubation-period-dogs) - [Distemper in Dogs: Symptoms, Timeline, and Causes](/knowledge/veterinary-medicine/parasitic-diseases/distemper-dogs-symptoms-timeline) - [Distemper Vaccine for Dogs: Schedule and Contagiousness](/knowledge/veterinary-medicine/preventive-and-routine-care/distemper-vaccine-dogs) - [Canine Distemper Virus](/knowledge/viruses/pet-viruses/canine-distemper-virus) ## References 1. [Canine distemper virus](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/canine-distemper-virus). Cornell University College of Veterinary Medicine. 2. [Canine Distemper - Infectious Diseases](https://www.merckvetmanual.com/infectious-diseases/canine-distemper/canine-distemper). Merck Veterinary Manual. 3. [Detection and Phylogenetic Characterization of Canine Distemper Virus from a Red Fox in Hungary](https://pubmed.ncbi.nlm.nih.gov/41902260/). Viruses, 2026. ## Further Reading - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)