DISTEMPER

Written by Jennifer Davies

Runny nose, a nasty cough, gunky eyes, fatigue, aches and pains… Sounds like a bout of the ‘flu, right? But, in dogs, these signs can be an indication of something far more serious developing… You could be dealing with canine distemper.

What is distemper?

Canine distemper – usually just called “distemper” – is an incurable disease caused by a highly contagious virus in the same family that causes measles in humans. The virus infects dogs, and variations of it can affect other carnivores too. Fortunately, you cannot catch it from animals and your dog can’t catch measles from you – they’re related but not the same.

Even though there has been a commercially available vaccine since the 1950s, in countries like South Africa, where there are many unvaccinated, often free-roaming dogs and wildlife, distemper is still a leading cause of death in puppies.

The virus affects the whole body, particularly the respiratory, nervous, and gastrointestinal systems, and, in immune-compromised dogs and puppies, it can rapidly be fatal. After an incubation period of one week to 21 days, distemper usually starts with a mucosal phase in which it attacks mucus membranes, causing signs like coughing and a runny nose. This may be accompanied, followed, or sometimes preceded by a gastrointestinal phase in which the dog has diarrhoea and/or vomiting. Next, it attacks the nervous system, causing seizures, twitching, and paralysis. The virus can also affect lymphatic tissue and suppress immune function, thus making it even harder to fight it off and allowing secondary infections like pneumonia to develop.

As there’s no cure, even with the best supportive treatment, up to 80% of puppies and around 50% of adult dogs don’t make it.

So, why is it called distemper? Historically, people believed that diseases were caused by an imbalance in what they called humours – or tempers; the name comes from the Middle English word “distempere”, meaning “to upset the balance of the humours”.

What does distemper look like?

In advanced distemper cases, it’s generally pretty obvious to anyone experienced in dealing with it – these dogs have a typical appearance, looking very depressed, weak, dehydrated, and with thick “gunk” coming out of their nose and eyes.

However, distemper infection has phases and it’s not always this obvious, particularly in the early stages or less severe infection. It has many signs in common with other diseases, which makes diagnosis trickier.

This is why it’s important to know as much about your dog’s health and vaccination history as possible; always be aware of what’s going on with their behaviour, eating habits, and overall well-being, and keep an eye out for news of distemper outbreaks.

Phase 1 (mucosal phase)

The first phase usually starts off looking like a cold or flu. This phase can be so mild that owners don’t even notice that their dog is sick, or so severe that it leads to death, particularly in puppies.

• Fever – it usually starts off with a short-lived fever, often accompanied by poor appetite and depressed behaviour. This subsides fairly quickly, followed about a week later by another fever which lasts around a week. This is generally when respiratory and gastrointestinal symptoms (see below) begin to show.
• Lethargy and depression
• Loss of appetite
• Sneezing
• Coughing
• Nasal discharge (“runny or snotty nose”) and/or ocular discharge, which can start out clear and become gloopy and crusty
• Vomiting and/or diarrhoea, which can lead to dehydration*
• Fever ("Does your pet have a fever?")
• Some dogs develop “hard pad”, which is where the skin of the nose leather and pads of the feet becomes calloused, thickened, and hard (hyperkeratosis). In fact, an old name for distemper was hard pad disease. This never goes away, so you may see it on the few dogs that have survived the infection.
• Puppies that still have their baby teeth may have damage to the tooth enamel, resulting in weakened teeth later in life.
• Skin pustules (like pimples) can appear on some dogs.

*How to check if a dog is dehydrated:

Using your thumb and forefinger, gently pinch the skin on the scruff of the neck, pulling it up by about 6 to 8cm (forming a tent). When you release it, the skin should immediately go back to normal; if it takes more than two seconds, this indicates dehydration. Another way to check is to gently lift the lip and touch their gums, if the dog allows it – they should feel moist; if they feel dry and/or sticky, this could indicate dehydration. A severely dehydrated dog may also have sunken eyes.

Phase 2

If the dog survives phase 1, distemper moves on to the neurological phase, in which the central nervous system is attacked. Sadly, dogs that enter this phase are even less likely to recover, and if they do, they’re highly likely to have lifelong neurological problems. Dogs may seem to recover from phase 1 and then, one to three weeks later, start showing these signs, or they may start while the dog is still in phase 1. You may see:

• Disorientation, confusion, and imbalance

• Muscle twitching, tremors, and localised seizures, often starting in the head and jaw, leading to the classic distemper sign known as “chewing-gum fits”, characterised by jaw movements that look like the dog is chewing bubble gum. There may also be tremors and twitches in the legs and shoulders.
• Generalised seizures
• Paralysis (lameness), usually starting with the back legs
• Nystagmus (eyes twitch involuntarily back and forth, up and down, or in circular movements)
• Collapse

Old dog encephalitis

In very rare cases, dogs can develop chronic distemper encephalitis (brain inflammation), also called “old dog encephalitis”, sometimes only showing up years after the initial infection. After initial infection and phase 1 (which is often not even detected), the dog recovers but the virus stays and attacks the central nervous system, remaining undetected but all the while causing inflammation and damage. These dogs will suddenly show strange signs like constant pacing, lack of coordination, pressing their heads against things like walls and furniture, and unsteady walking, and there’s usually no history of other distemper signs. Some people refer to this as “latent distemper”. Although it’s not well understood why this happens, fortunately, it’s extremely rare.

How could my dog get distemper?

This virus is highly contagious between dogs, so it’s important to know how it spreads so that you can try to prevent it.

The distemper virus is found in bodily excretions, particularly respiratory secretions (e.g. eye, nose, lungs) but also urine, faeces and vomit. It’s transmitted in the following ways:

1. In utero: Puppies can get distemper through the placenta if their mother has the virus. The virus often causes spontaneous miscarriage and stillbirths but, if the pups are born, they’re likely to be weak and have compromised immune systems and/or neurological symptoms (similar to a pregnant human catching measles), or develop cardiomyopathy or heart failure.
2. Airborne: When an infected dog sneezes or coughs, the virus can be transmitted in tiny droplets to other dogs in the vicinity – up to a 1.2 metre radius, or more under the right conditions.  
3. Direct contact: This is the most common method of transmission, particularly in areas where many dogs live close together and intermingle freely. It can happen when, for example, dogs greet each other by putting their noses near each other, or even via droplets an infected dog leaves on food bowls, your clothing, grass, etc. The virus survives a few hours outside the body at room temperature, so it’s possible that, even if you don’t see another dog, your dog could still come into contact with the virus.

How will I know if my dog has distemper?

The only way to know for sure is with certain tests which a veterinarian can administer. It’s not always easy to diagnose, particularly in the early stages, so several tests may be needed.

These include:

• Taking a swab of secretions from the nose (a lot like the Covid tests) and sometimes the eyes; sometimes, vomit or faeces are tested. This swab sample is mixed with a substance called a reagent and placed on a small plastic “cassette”, after which you’ll usually need to wait 10 to 15 minutes for a result.
• Your vet may draw blood in order to check for things like a raised white blood cell count, and to try and eliminate other infections as a possible cause.
• If results are inconclusive but the vet still suspects distemper, they may also test urine, vomit or blood.
• A chest x-ray might be recommended to check for pneumonia.
• In dogs with neurological signs, cerebrospinal fluid tests can be done but usually only as a last resort as they’re invasive, expensive, and results take time.

Note that it’s important to tell the vet as much as you can about your dog’s full history, especially vaccinations. It’s possible to get a false positive result on a test if your pup was vaccinated in the last one to three weeks.

What is the treatment for distemper?

Unfortunately, there’s no cure; there’s only supportive treatment… and hope. Your pet will need to stay in hospital in an isolation ward for around-the-clock monitoring, and may receive intravenous fluids (a drip), anti-diarrhoeal and anti-nausea drugs, antibiotics in case of secondary infections, and possibly even anti-seizure medication.

They can be in hospital for a long time, which is stressful to you and your dog, and can be very expensive, with no guarantee of recovery. This is why it’s so crucial that you take steps to prevent them from getting it in the first place.

How can I protect my pet?

As dire as canine distemper is, the good news is that we can protect dogs from being infected.

Don’t be too late – vaccinate!

The number one thing you can do is to follow the recommended vaccination schedule – just once is not enough. If administered correctly, the distemper vaccination is 99% effective. Your vet can advise you on how to proceed with vaccinations as this varies, depending on factors such as their age, history, and overall health.

Follow precautionary measures: (These measures will help to prevent spread of any infectious diseases, including parvo.)

1. Avoid early separation. Puppies should stay with their mother until at least eight weeks old because they receive some protection from her if she has immunity. This only lasts a few weeks, which is why it’s important to have them vaccinated according to schedule. In cases where early separation is unavoidable, such as orphaned puppies, consult a veterinarian experienced in neonates.
2. Choose wisely. Don’t get puppies from pet shops, backyard breeders, and puppy mills, as these animals often live in substandard conditions, don’t get the right care and vaccinations, and there’s a much higher risk that they could be carrying diseases. Either adopt from a reputable animal welfare which quarantines new puppies before rehoming and has an effective vaccination programme, or, if you really want to buy, only support responsible breeders that adhere to the highest standards.
3. Keep pups home. Ideally, puppies shouldn’t be taken anywhere other than the vet (where they should be carried in and not allowed to interact with other patients) until they’ve completed all their vaccinations. To ensure that they don’t miss out on valuable socialisation time, enrol them at a reputable puppy socialisation class where they insist on age-appropriate vaccinations for all attendees and follow good hygiene measures. Avoid taking them to dog parks, beaches, or other places where lots of dogs congregate.
4. Support good health. Ensure that your pooch gets good-quality food and, if needed, nutritional supplements and probiotics, as this helps to keep the immune system strong. Keep their stress levels low and ensure adequate but not excessive exercise.
5. Observe good hygiene. Always wash your hands before and after handling your pup. If you think you’ve had contact with potentially contaminated items or sick dogs, change into clean clothing before giving your furry family member a cuddle. If you’re very concerned or regularly work with other dogs, invest in a bottle of veterinary disinfectant, available from most vet/pet shops.
6. Be responsible. If you have a dog suffering from distemper, it’s up to you to protect others. Keep them isolated, and when you take them to the vet, advise the practice in advance so that they can take precautions to keep other dogs safe – don’t just walk a sick dog through the waiting room. If your dog is one of the lucky ones that survives, be aware that they can still be contagious for up to four months after recovery, so keep them home and disinfect yourself before leaving the house.

Cleaning up after distemper

The distemper virus is contagious but, fortunately, isn’t very durable outside the body. It’s easily destroyed in the environment with proper cleaning and exposure to sunlight and dry heat.

Most household cleaners, if used correctly, will destroy the distemper virus – even hot soapy water should do the trick. If you prefer something stronger, one part bleach to 20 parts water is an effective disinfectant, or purchase a veterinary disinfectant from a vet/pet shop. (Be careful when applying any cleaners to furnishings, etc.)

Remember to clean kennels and crates; floors, doors, lower parts of walls, furniture, etc.; pet accessories, including bowls, leashes, bedding, etc. If possible, once you’ve cleaned items, place them outside in the sun to dry and ventilate the house.

Note: It’s best to avoid using cleaning agents around animals – rather take them out of the room and bring them back in once everything has dried and aired out.

Protecting your pet protects everyone

Preventing distemper among our dogs doesn’t just protect them and other canine companions. Distemper can affect other wild animals such as mongoose, meerkat, otters, genets, hyenas, and even lions, leopards, and cheetahs. In 1994, a distemper outbreak in the Serengeti National Park led to the deaths of over a third of the park’s lions and affected many other species; the source of the outbreak is thought to have been unvaccinated, free-roaming domestic dogs. Numerous cases of endangered African wild dogs (of which there are less than 6,000 remaining in the wild) dying from distemper have been recorded, several of these outbreaks wiping out entire packs.

As a responsible pet parent, it’s crucial that we protect them from dread diseases like distemper and, in so doing, we help to protect other animals too.  

Important: The above is intended for informative purposes only and doesn’t replace the advice of a veterinarian. Should you have any concerns about your pet, please contact a vet as soon as possible.