# Distemper in Dogs: Symptoms, Timeline, and Causes Distemper in dogs symptoms usually begin as a fever with runny eyes and nose, poor appetite, and tiredness, then may move into vomiting, diarrhea, and coughing. Weeks later, some dogs develop twitching, seizures, or balance problems. Distemper is a highly contagious viral disease that occurs worldwide and can be fatal [1]. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Distemper is caused by canine distemper virus, a highly contagious virus that affects the whole body and spreads easily in places with low vaccination rates and many dogs [2]. - Early signs look like a bad cold or stomach bug: fever, lethargy, loss of appetite, nasal discharge, and diarrhea [1]. - Neurologic signs such as muscle twitching and seizures can appear at the same time as other signs, after them, or sometimes alone, and may be delayed [1][3]. - There is no specific cure. Treatment manages symptoms and prevents secondary infections [2]. - Vaccination is very effective at preventing distemper and is a core vaccine for every dog [2]. ## What Is Distemper in Dogs? Canine distemper is a systemic viral disease, meaning it can affect the entire body instead of one organ system [1]. The virus commonly targets epithelial tissue (the cells lining surfaces like the airways and gut), lymphoid tissue (part of the immune system), and nervous tissue [4]. That wide reach explains why the signs are so varied and why the disease can look like several different illnesses at once. The virus belongs to the genus Morbillivirus [5]. It affects dogs and other carnivores, including ferrets, raccoons, skunks, and foxes [2]. It occurs worldwide [1]. In communities with low vaccination rates and high dog populations, spread is more likely [2]. One of the hardest parts of distemper is timing. Infected dogs become contagious to other dogs several days before they show any signs of illness [2]. Even mildly affected dogs can look well while shedding significant amounts of the virus [2]. By the time you notice something is wrong, your dog may already have exposed other dogs. ## Distemper in Dogs Symptoms: What You Will Actually See Signs vary in severity from subclinical (no obvious illness) to rapidly life-threatening [2]. Young or unvaccinated dogs are most susceptible [2]. Here is what owners most often notice, grouped by body system. ### Early systemic signs - Fever - Lethargy - Loss of appetite [1] These are vague. A dog with a fever and no appetite could have any number of problems, which is why distemper can be missed early [2]. ### Respiratory and eye signs - Nasal discharge - Pneumonia - Eye discharge [1] ### Gastrointestinal signs - Vomiting - Diarrhea [1] Diarrhea is a common reason dogs with distemper get tested. In one study of dogs in public kennels, 46.7% of dogs with diarrhea tested positive for the virus, compared with 18.4% of healthy dogs [5]. That does not mean every dog with diarrhea has distemper. It does mean distemper belongs on the list of possibilities, especially in unvaccinated dogs. ### Neurologic signs Nervous system signs can occur at the same time as the other signs, after them, or sometimes alone [3]. They include: - Muscle twitching - Focal or generalized seizures [1] - Circling (walking in a circle instead of a straight line) - Head tilt - Uncontrolled rapid eye movements [3] Long-term infection can cause inflammation of the brain. This form is often associated with poor coordination, behaviors like pressing the head against objects or constant pacing, and exaggerated muscle movements [3]. These signs can appear in adult dogs even if they never showed earlier distemper signs, and they usually worsen over time [3]. Dogs with this form of the disease do not typically spread it to other dogs [3]. Some of these neurologic behaviors can resemble other problems, including pain or anxiety-driven conditions. If you are trying to sort out whether a behavior change is medical or behavioral, our guide to [dog behavior problems](/knowledge/veterinary-medicine/behavior/dog-behavior-problems-list) can help you organize what you are seeing before your vet visit. ## The Distemper Timeline in Dogs The timeline is one of the most confusing parts of this disease, because it is not a straight line. | Stage | Typical timing | What you may see | |---|---|---| | Incubation and shedding | Signs can appear from less than a week up to six weeks after exposure | Nothing yet, but your dog can already be contagious [2] | | Early systemic | First days of illness | Fever, lethargy, poor appetite [1] | | Respiratory and GI | Days to weeks | Nasal and eye discharge, pneumonia, vomiting, diarrhea [1] | | Neurologic | Same time as other signs, after them, or delayed | Twitching, seizures, circling, head tilt, eye movement changes [1][3] | | Chronic neurologic | Weeks to months later | Poor coordination, head pressing, pacing, exaggerated movements that worsen over time [3] | The key point is that a dog can seem to improve after the respiratory and GI phase and then develop neurologic signs later. That gap is why veterinarians monitor recovering dogs closely and why a dog that "got better" still needs follow-up. ## What Causes Dog Distemper? Distemper is caused by canine distemper virus, also called canine morbillivirus [6]. Dogs get it from other infected animals. Because infected dogs shed the virus before they look sick, and because mildly affected dogs can shed large amounts, outbreaks can move through a group before anyone realizes there is a problem [2]. The virus is a multi-host pathogen, meaning it infects more than one species [7]. Wild carnivores such as foxes and jackals can carry and spread it, and the growing overlap between wildlife, peri-urban areas, and domestic dogs raises concern about wildlife as a source of infection [7]. This is one reason distemper keeps circulating even in areas where most pet dogs are vaccinated. Risk factors that raise a dog's chance of infection include: - Being young or unvaccinated [2] - Living in or visiting communities with low vaccination rates and high dog populations [2] - Being in kennels, shelters, or other group settings, where the virus circulates readily [5] - Contact with free-roaming dogs, which can maintain the virus in a population [8] If your dog has diarrhea, weight loss, or a dull coat, parasites are another common culprit and can occur alongside viral illness. Our article on [what are the signs and symptoms of a dog with worms](/knowledge/veterinary-medicine/parasitic-diseases/what-are-the-signs-and-symptoms-of-a-dog-with-worms) covers those signs so you can tell your vet the full picture. ## How Distemper Is Diagnosed Diagnosis starts with recognizing the clinical signs, then confirming with laboratory testing [1]. Because the early signs overlap with many common diseases, recognition alone can be a challenge [2]. Your veterinarian may use: - Antibody assays, which look for the dog's immune response to the virus [1] - Reverse transcriptase PCR, which detects the virus's genetic material [1] - Quantitative PCR, considered the current test of choice for detecting the virus [2] - PCR or virus isolation to confirm infection and to determine whether a recovered dog is likely still infectious to other dogs [2] Samples can come from blood, feces, and urine [5]. In one study, researchers successfully established a PCR technique using those sample types, which matters because it gives veterinarians flexibility in what they collect [5]. Your vet will also consider other infections that cause similar signs. Distemper does not have a single signature sign that makes it obvious, so testing matters. ## Treatment Options for Distemper There is no specific treatment or cure for canine distemper, and antivirals are not recommended [2]. The goal of treatment is to manage symptoms and prevent secondary infections [2]. Supportive care may include: - Fluids to correct dehydration from vomiting, diarrhea, and poor drinking - Medications to control vomiting, diarrhea, or seizures, chosen and dosed by your veterinarian based on your dog's weight and health - Nutrition support if your dog will not eat - Antibiotics if a secondary bacterial infection such as pneumonia develops - Nursing care to keep the eyes and nose clean and to keep your dog comfortable Because there is no antiviral cure, the intensity of care depends on how sick your dog is. Some dogs need only outpatient support. Others need hospitalization with oxygen, intravenous fluids, and seizure control. Your veterinarian will calculate any medication dose from your dog's weight and current health, and doses change as your dog's condition changes. ## Recovery, Outlook, and Long-Term Management The prognosis varies with the severity of the neurologic signs [1]. Dogs with mild or no neurologic involvement have a better chance of surviving. Dogs with severe or worsening neurologic disease have a guarded outlook. ### Signs of a dog recovering from distemper Owners often ask what recovery looks like. In general, a recovering dog: - Regains appetite and drinks normally - Has less eye and nose discharge - Stops vomiting and has formed stools again - Gains energy and interacts with the family again - Has stable or improving neurologic signs, with no new twitching or seizures Recovery does not always mean the virus is gone from the body. Some dogs develop long-term brain inflammation with signs like poor coordination, head pressing, and constant pacing that worsen over time [3]. If your dog shows these behaviors, that is a medical problem, not a training problem. Our article on [dog behavior issues causes](/knowledge/veterinary-medicine/behavior/dog-behavior-issues-causes) explains how medical conditions can show up as behavior changes. ### Distemper in dogs teeth One of the most distinctive long-term effects shows up in puppies that survive. Distemper can damage the cells that form tooth enamel, leaving permanent enamel defects. This is why some dogs that had distemper as puppies have teeth with pitted, discolored, or missing enamel. The damage happens while the adult teeth are still forming, so it cannot be reversed later. It is a permanent record of the infection. These teeth may be more prone to tartar buildup and decay, so ask your veterinarian about a dental care plan. ### Infectiousness after recovery A recovered dog may or may not still be contagious. PCR or virus isolation testing can help determine whether a recovered dog is likely still infectious to other dogs [2]. Do not assume your dog is safe to be around other dogs until your veterinarian confirms it. ## Prevention Vaccination is available and generally effective [1]. It is very effective at preventing distemper and is a core vaccination for every dog [2]. Practical steps: - Keep your dog's core vaccines current, including the distemper combination vaccine. Follow your veterinarian's schedule for puppies and adults. - Limit contact with unknown dogs, especially for puppies who have not finished their vaccine series. - Be cautious in group settings such as kennels, shelters, and dog parks if vaccination status is unknown. - If you foster or adopt, quarantine new dogs away from your resident dogs until a veterinarian clears them. - Report wildlife contact. Distemper circulates in foxes, jackals, raccoons, skunks, and other carnivores, so keep your dog away from wildlife [2][7]. If your dog has worms or other parasites on top of a viral illness, that adds strain. Our article on [symptoms my dog has worms](/knowledge/veterinary-medicine/parasitic-diseases/symptoms-my-dog-has-worms) can help you spot those signs early. ## Limitations and When to Contact a Veterinarian No article can tell you whether your individual dog has distemper. Only a veterinarian who examines your dog and runs appropriate tests can do that. Individual cases need a veterinarian. Contact your veterinarian the same day if your dog has: - A fever with poor appetite and lethargy - Eye or nose discharge that is new or getting worse - Vomiting or diarrhea that lasts more than a day, or that comes with blood - A cough or trouble breathing - Any new twitching, head tilt, or unsteadiness Go to an emergency clinic now if your dog has: - A seizure, especially a first seizure or more than one - Trouble breathing or blue gums - Collapse or inability to stand - Severe, repeated vomiting or diarrhea with signs of dehydration (tacky gums, sunken eyes, no urine) Call for a routine visit if your dog survived distemper and you have questions about dental enamel defects, ongoing neurologic monitoring, or when it is safe to be around other dogs again. ## Frequently Asked Questions ### How long does distemper last in dogs? Signs can appear from less than a week up to six weeks after exposure, and the illness can run for weeks after that [2]. Neurologic signs may show up later or worsen over months [3]. There is no fixed end date, which is why follow-up care matters. ### Can a dog survive distemper? Yes, some dogs survive, especially with supportive care. The outlook depends heavily on how severe the neurologic signs are [1]. Puppies that survive often carry permanent enamel damage on their adult teeth. ### Is distemper contagious to humans or other pets? Distemper is not a human disease, but it is highly contagious among dogs and other carnivores such as ferrets, raccoons, skunks, and foxes [2]. Infected dogs can spread it before they look sick [2]. Keep sick dogs away from other dogs and wildlife. ### How is distemper different from kennel cough? Kennel cough is a respiratory illness, while distemper is a whole-body viral disease that can also affect the gut and nervous system [1]. Distemper can cause pneumonia, diarrhea, and seizures, and it can be fatal. A veterinarian can tell them apart with an exam and testing. ### Can my dog get distemper again after recovering? Survivors typically develop immunity after infection, but the bigger concern is whether a recovered dog is still shedding virus. PCR or virus isolation testing can help determine if a recovered dog is likely still infectious to other dogs [2]. Ask your veterinarian before reintroducing your dog to other dogs. ## Related Articles - [Dog Behavior Problems List](/knowledge/veterinary-medicine/behavior/dog-behavior-problems-list) - [Dog Behavior Issues Causes](/knowledge/veterinary-medicine/behavior/dog-behavior-issues-causes) - [What Are The Signs And Symptoms Of A Dog With Worms](/knowledge/veterinary-medicine/parasitic-diseases/what-are-the-signs-and-symptoms-of-a-dog-with-worms) - [Dog Behavior Issues List](/knowledge/veterinary-medicine/behavior/dog-behavior-issues-list) - [Symptoms My Dog Has Worms](/knowledge/veterinary-medicine/parasitic-diseases/symptoms-my-dog-has-worms) - [Dog Obstruction Symptoms](/knowledge/veterinary-medicine/symptom-guides/dog-obstruction-symptoms) ## References 1. [Canine Distemper - Infectious Diseases](https://www.merckvetmanual.com/infectious-diseases/canine-distemper/canine-distemper). Merck Veterinary Manual. 2. [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. 3. [Canine Distemper (Hardpad Disease) - Dog Owners](https://www.merckvetmanual.com/dog-owners/disorders-affecting-multiple-body-systems-of-dogs/canine-distemper-hardpad-disease). Merck Veterinary Manual. 4. [Placentitis and abortion caused by canine distemper virus in a Linnaeus's two-toed sloth](https://pubmed.ncbi.nlm.nih.gov/42668364/). Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 2026. 5. [Investigation of the canine distemper virus in dogs living at public kennels in Northern Brazil: validation of a detection assay](https://pubmed.ncbi.nlm.nih.gov/40804190/). Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], 2025. 6. [Baculovirus expression and purification of nucleocapsid protein of canine distemper virus for its evaluation as a diagnostic antigen](https://pubmed.ncbi.nlm.nih.gov/41313480/). Archives of microbiology, 2025. 7. [Molecular Evidence of Canine Distemper Virus Circulation in Red Foxes and Golden Jackals from Western Romania](https://pubmed.ncbi.nlm.nih.gov/42654997/). Microorganisms, 2026. 8. [Seroprevalence of canine distemper in free-roaming dogs in buffer zone of Bardiya National Park, Nepal](https://pubmed.ncbi.nlm.nih.gov/42251375/). BMC veterinary research, 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)