Overview
Canine distemper is a serious illness that can affect your dog’s lungs, heart, immune system, stomach, and brain. It’s caused by a virus similar to measles and can be life-threatening, especially for puppies or unvaccinated dogs. There’s no cure — just supportive care while their immune system fights it off.
Thanks to vaccines, distemper is now much less common in the UK, but it hasn’t gone away completely. In places where fewer dogs are vaccinated, it can still spread. Dogs that recover may be left with lasting effects, like twitching or seizures. It’s sometimes called ‘hard pad disease’ because it can make their nose and paw pads thick and rough.
What are the symptoms of distemper in dogs?
Spotting the signs of distemper early can really help. It doesn’t look the same in every dog — some might seem just a bit under the weather at first, while others can become seriously unwell quite quickly. The sooner they get care, the better their chances of recovery. That’s why it’s good to know what to watch out for.
Early signs of distemper may include:
A fever that comes and goes
Low energy or seeming ‘off’
Watery or sticky eyes
A runny or crusty nose
Vomiting or diarrhoea
This early stage can be tricky. Dogs often seem to improve before they get worse. Because distemper affects the immune system, even a mild case can lead to bigger problems like pneumonia or tummy upsets.
As canine distemper progresses, signs may include:
A hard nose or thickened paw pads
Twitching, especially in the face or legs
Weakness or stiffness
Seizures (sometimes with chewing motions or drooling)
A head tilt or walking in circles
Wobbliness or trouble walking
Partial or full paralysis
These later signs don’t always appear straight away. They can take three to four weeks to show — sometimes even after your dog seems to be on the mend. In some cases, they come on suddenly or can linger long after your dog has recovered, especially if their brain or spine has been affected.
In puppies, the virus can affect how their adult teeth form, sometimes leading to lasting damage to the enamel. It can also cause changes to their skin or problems with their eyes, although that’s less common.
Not every affected dog will have all these signs. But if you spot any combination of them — especially in a dog who hasn’t been vaccinated — it’s best to speak to your vet as soon as possible. Catching distemper early gives your dog the best chance of a smoother recovery.
Read more: Common questions on dog vaccinations
How does distemper in dogs spread?
Distemper spreads easily between dogs, mainly in the air through coughs, sneezes, or barks from an infected dog. It can also pass through saliva, urine, poo, or shared items like bowls, bedding, and toys. Dogs can also be infected via contact with affected wild animals, such as foxes.
One of the tricky things is that dogs can pass the virus on before they even seem unwell — often just a week after catching it. And even once they look better, they might still be contagious for weeks or even months, especially if their brain or nerves have been affected.
Regular household disinfectants can kill the virus, and it doesn’t survive long on surfaces. But it can stick around in cool, damp places.
Who’s most at risk of canine distemper?
Puppies under six months and unvaccinated dogs are most at risk. Dogs who live closely with others (like in kennels, shelters, or rescue centres) also have a higher chance of catching it. Some adult dogs with partial immunity may only seem a bit off, but they can still spread the virus. Pregnant dogs can even pass it to their unborn pups through the placenta.
How is distemper in dogs diagnosed and treated?
Because distemper shares symptoms with other illnesses, it’s not always easy to spot. Your vet will look at your dog’s signs, check their vaccination history, and run some tests to help work out what’s going on. These tests might include swabs or blood samples to check for the virus or see how your dog’s immune system is responding. A PCR test, run on either blood or swabs of nasal or eye discharge, can pick up traces of the virus, while blood tests for antibodies show whether their body is fighting it. If your dog’s struggling to breathe, your vet may also suggest X-rays or scans to check for pneumonia.
Sometimes the results aren’t clear-cut — especially if your dog has been vaccinated recently, or if the illness is at a later stage. That’s why your vet will also watch closely to see how your dog’s doing and how they respond to care.
There’s no medicine that cures distemper, so treatment focuses on easing symptoms and helping your dog fight the virus. What your vet suggests will depend on how your dog is doing and what signs they’re showing. Care might include:
Fluids to stop them getting dehydrated from vomiting or diarrhoea
Medicine to help with sickness, diarrhoea, or a high temperature
Antibiotics to treat infections while their immune system is low
Medication to manage seizures, if needed
Nutritional support, especially if they’ve gone off their food
Hospital care if things get more serious (like breathing issues or repeated seizures)
How do I look after my dog after recovering from distemper?
Recovery from distemper can take time — and it’s not always simple. Some dogs bounce back in a few weeks, while others need months. For some, the effects may last a lifetime. How your dog recovers often depends on when treatment started and whether their brain or nerves were affected. Even once they seem better, your dog might still be contagious — sometimes for weeks or even months. This is more likely if they had signs affecting their brain or nerves. That’s why it’s so important to keep them away from other dogs and follow your vet’s hygiene advice until they say it’s safe.
During recovery, ongoing care makes a big difference. This might include:
Regular check-ups to monitor progress and adjust care
Gentle exercise or physiotherapy to help rebuild strength and balance
Support with eating and nutrition
A calm, quiet space where they can rest and heal
Keeping them apart from other dogs to avoid spreading infection
Some dogs make a full recovery from distemper. Others may have lasting effects that show up weeks or even months after they seem better. These can include:
Muscle twitches or tremors
Ongoing seizures or other problems with the nervous system
Changes in behaviour or balance
Dental issues in dogs infected as puppies (like weak or damaged enamel)
Long-term breathing problems, or hardened paw pads and nose
One rare complication is called ‘old dog encephalitis’ — a type of long-term brain inflammation. It usually appears later in life, often in dogs who seemed to recover well. It’s not common, but it’s worth keeping in mind if new signs appear.
Read more: How to brush your dog's teeth
Do vaccines stop distemper in dogs?
Distemper is preventable due to a widely available and highly effective vaccine. It’s covered by your dog’s routine vaccinations (see our puppy vaccination schedule guide for all the details), and regular boosters help keep that protection strong throughout their life.
Other ways to help stop the spread of distemper:
Avoid taking unvaccinated puppies to busy places like parks, training classes, or kennels
Carry them when you’re out and about until their vaccination course is complete
Keep them away from dogs who are unwell or not vaccinated
Ensure female dogs are fully vaccinated before planning a litter
Be cautious when bringing new dogs home if you don’t know their vaccine history
Clean food bowls, toys, and bedding regularly — especially if you have more than one dog
Choose groomers, kennels, or day-care centres that check for up-to-date vaccinations
Vaccination is the best way to protect your dog. But for young pups, older dogs, or those with weaker immune systems, these extra steps help reduce the risk even more.
Canine distemper FAQs
Is distemper still a threat in the UK?
Yes — though it’s now not as common, thanks to effective vaccines. Outbreaks can still happen, especially if infected dogs arrive from abroad or if fewer dogs are being vaccinated.
Can humans or cats catch distemper from dogs?
No. Distemper doesn’t affect people or cats — only certain animals like dogs, foxes, and ferrets.
How long can a dog be contagious after recovering?
Some dogs can still pass the virus on for weeks — or even months — after they seem better. This is more likely if their brain or nerves were affected.
Can a vaccinated dog still get distemper?
It’s very unlikely. No vaccine is perfect, but staying up to date with boosters gives your dog the best protection.
Why does distemper sometimes seem to come back after improvement?
Distemper often has two phases. Some dogs seem to improve at first, then go on to develop more serious signs — especially if their brain or nerves are affected.
What if my dog was imported from another country?
Dogs from abroad may come from places where distemper is more common. If you’ve adopted one, it’s a good idea to check their vaccination history and chat with your vet about what to do next.
Is canine distemper treatment expensive?
There’s no cure for distemper, so care focuses on managing symptoms — things like hospital stays, medication and longer-term support. This can add up, especially as recovery often takes some time. Pet insurance or a health plan can help spread the cost and make it more manageable.
What do studies on distemper in dogs say?
Distemper affects more than just dogs
Canine distemper virus can infect a wide range of animals. In the UK, it’s found in foxes, badgers, and ferrets — all of which can carry the virus and pass it on to dogs. But the risk goes both ways. Dogs, especially those that aren’t vaccinated, can also spread it back to wildlife and trigger new outbreaks.
Research from other countries has found the virus in wolves and badgers in Italy, and even in endangered tigers in Asia. This study also detected it in tree shrews in the same parts of the world. But there is some good news — domestic cats aren’t at risk from canine distemper. While the virus can affect some big cats, our pet cats are safe.
Roaming dogs can fuel the spread
In areas where many dogs roam freely and vaccination rates are low, distemper spreads fast. One study in Mexico found that over half the dogs near protected wildlife zones had been exposed to the virus — likely because they weren’t vaccinated and could move around unchecked.
Vaccine-related illness is extremely rare, but worth knowing about
Distemper vaccines are very safe and highly effective. But in rare cases, some young puppies may develop symptoms similar to distemper after having a live vaccine. One study in New Zealand found that nine puppies became unwell within three weeks of vaccination. In six of those cases, the symptoms were linked to the vaccine strain — not to the virus in the environment.
This kind of reaction is extremely rare, but it’s a good reason to keep a close eye on puppies after they’ve had their jab. If you notice signs like a fever, tremors, seizures or breathing problems — especially in the first month — contact your vet straight away. Vaccination is still the best way to protect dogs from distemper. But if side effects do happen, it’s important to let your vet know.
Did distemper come from human measles?
A recent study in Mexico suggests distemper may have started as a form of human measles, passed to dogs centuries ago — possibly by early European settlers in the Americas. While the virus has since spread around the world, its link to humans gives us a fascinating glimpse into how viruses can change and cross between species. For dog owners, this kind of research is a helpful reminder: vaccinate your dog early, keep their boosters up to date, avoid contact with wildlife, and speak to your vet if you notice any worrying signs — especially in puppies.
What’s the history of distemper in dogs?
Distemper has been around for centuries. Before vaccines, it was one of the biggest threats to dogs in Britain — especially puppies and working dogs. Outbreaks were common and often deadly. Edward Jenner, best known for creating the smallpox vaccine, was one of the first to recognise distemper as a disease in dogs. His work helped pave the way for future breakthroughs in treatment and prevention.
By the early 1900s, scientists in the UK had developed one of the first reliable distemper vaccines. It was a huge step forward — and it saved countless lives. Today’s vaccines are safer and more effective than ever. Thanks to them, distemper is now much less common in the UK. But the virus hasn’t gone away, and cases can rise again if we stop protecting against it.
Need more advice on distemper in dogs?
For more information on canine distemper and the vaccination process, contact your local vet. And remember, Pet Health Club membership includes your dog's core vaccinations, keeping them safe from not just canine distemper, but other dangerous diseases too.
Find your nearest vet using our Find a Vet page.
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Medically reviewed by Lizzie Youens, BSc(Hons) BVSc MRCVS
Published on 18/06/2018 • Reviewed on 17/11/2025