Understanding distemper

What is distemper?

Distemper is a highly contagious viral disease that attacks a dog’s respiratory, gastrointestinal, and nervous systems. Thanks to widespread puppy vaccinations in the UK, distemper has largely disappeared from daily life, but it is one of the most common illnesses we see here in Sri Lanka.

The virus – canine distemper virus (CDV) – spreads rapidly through coughs, sneezes, urine and faeces. It can lead to severe neurological damage (affecting the brain and nerves), a weakened immune system, and poor quality of life. In many cases, it can also be fatal.

But thankfully, distemper is preventable through vaccination, helping dogs stay healthy and live life to the fullest.

Does distemper only affect dogs?

Canine distemper doesn’t just affect dogs. Many wild and domestic animals can be affected, including foxes, wolves, raccoons, ferrets and larger animals like big cats.

It doesn’t affect humans, though people can pass infections on from one dog to another through their hands or clothing, which is why infection control is very important.

Feline distemper

Cats have a condition called feline panleukopenia virus (FPV), which is sometimes referred to as “feline distemper”. However, it is caused by a completely different virus – the feline parvovirus.

Canine distemper and feline panleukopenia are different diseases and cannot be passed between domestic dogs and cats.

Feline panleukopenia is equally serious but, similarly to canine distemper, is preventable through vaccination. Every cat we sterilise is given the Tricat vaccine at the time of their operation, protecting them against feline panleukopenia virus (FPV), feline herpesvirus (FHV) and feline calicivirus (FCV).

What are the signs and symptoms of distemper in a dog?

Distemper symptoms are varied and may change or worsen over time. 

Discharge

One of the earliest and most recognisable signs is discharge from the eyes and nose. This often begins as a clear, watery fluid but can quickly become thick, yellow, or greenish as the infection progresses. Dogs may appear to have crusted, gunky eyes or a constantly runny nose. Sadly, some dogs may go on to experience sight loss and, in severe cases, may go blind.

Fever

An infected dog will usually develop a fever in the early stages of infection, sometimes as early as three to six days after exposure. They can also become lethargic, unusually quiet, or reluctant to move.

Cough and breathing difficulties

The dog may experience a dry cough first, followed by a moist ‘wet’ cough and later breathing difficulties, caused by pneumonia or another infection.

Loss of appetite and gastrointestinal symptoms

A dog with distemper will often stop eating or show little interest in food. For street dogs who are already surviving on limited resources, this can cause rapid weight loss and further weaken their immune system. They can also experience diarrhoea and vomiting.

Seizures and muscle twitching

As the virus attacks the nervous system, some dogs develop seizures, which can be distressing to witness. They may look as though they are uncontrollably shaking or they may suddenly collapse. This is a sign that the disease has progressed to a more advanced stage. You may notice tremors or twitching in the face, legs, or other parts of the body.

Difficulty walking

As distemper damages the nervous system, a dog may lose coordination and struggle to walk properly. They might stumble, appear unsteady on their feet or have difficulty rising from a resting position. In severe cases, partial or full paralysis can develop.

Canine distemper may also cause ‘hard pad disease’, when the surface of a dog’s nose and footpads thicken and harden. This is one of the most distinctive signs of the disease.

How does distemper spread?

The canine distemper virus mainly spreads through droplets in the air, which are produced when an infected dog coughs or sneezes. It can also be transmitted through shared food and water bowls, or through direct contact with an infected dog’s bodily fluids, such as urine, blood, saliva, or faeces.

Dogs are most likely to get infected and sick from the distemper virus when they are in groups, which is one of the reasons why it is common in Sri Lanka’s street dog population.

Why distemper is more common in stray dogs

Street dogs face a much higher risk of contracting distemper than dogs in homes for several reasons:

•       They are rarely vaccinated, leaving them with no immune protection against the virus.
•       They often live in close proximity to many other dogs, making it easy for the virus to pass from one animal to another.
•       Poor nutrition weakens their immune systems, making it harder for their bodies to fight off infection.
•       They have no access to regular veterinary care, so infections go undetected and untreated for longer.
•       Stress from living on the streets can further suppress their natural immune response.

This is why our vaccination and outreach programmes are so vital. Each vaccination doesn’t just protect one dog, it builds ‘herd immunity’ – where the disease can’t spread easily because most of the population is protected. Vaccination increases the chance of a happier, healthier dog population.

How distemper impacts a dog

Distemper does not just cause short-term illness, it can have lasting consequences for a dog’s quality of life, even for those who survive it.

Is distemper painful for dogs?

Yes, distemper can cause significant pain and discomfort. Symptoms can make it hard to breathe, cause vomiting and diarrhoea, and symptoms such as seizures and muscle twitching are distressing for the dog. Dogs suffering from advanced distemper are often exhausted, frightened, and in pain. 

Can a dog recover from distemper without treatment?

It is possible, but unlikely. Some adult dogs with strong immune systems may fight off the virus on their own, but many will not. Without veterinary care, the disease is often fatal, particularly in puppies, young dogs, and those already weakened by malnutrition or other illnesses. 

Dogs may also suffer permanent neurological damage, leaving them with ongoing tremors, seizures, or coordination problems for the rest of their lives. 

Treatment cannot cure the virus itself, but it can give a dog the best possible chance of survival and reduce long-term damage.

What treatment is available for distemper?

There is currently no antiviral medication that directly eliminates the canine distemper virus. Treatment is focused on managing symptoms, preventing secondary infections, and giving the dog’s immune system the best possible chance to fight back.

Treatment includes:

•       Intravenous fluids to combat dehydration from vomiting or diarrhoea.
•       Antibiotics to prevent or treat secondary bacterial infections.
•       Anti-seizure medications to manage neurological symptoms.
•       Nutritional support to help maintain strength and immunity.
•       Medication to reduce fever and ease breathing discomfort.

The earlier treatment begins, the better the outcome. Dogs treated in the early stages of infection have a far higher survival rate than those who receive care only once the disease has progressed. 

Vaccinating to prevent distemper

Vaccination is the single most powerful tool we have against distemper. The distemper vaccine is safe, effective, and widely available.

In many countries across the Global North it is included in the standard combination vaccine (often called the DHPL; distemper, hepatitis, parvovirus and leptospirosis) given to puppies and adult dogs.

Puppies can be vaccinated from around six to eight weeks old. They usually need a series of injections, given a few weeks apart, to build full protection – often two doses, though some have an extra booster up to around 16 weeks depending on the vaccine and the puppy. 

Adult dogs should receive regular boosters to maintain protection throughout their lives.

For street dogs, mass vaccination drives are one of the most impactful ways to reduce the spread of distemper across an entire community. When enough dogs are vaccinated, herd immunity begins to protect even those who haven’t been reached yet.

Here at Dogstar, prevention is at the heart of everything we do. We vaccinate thousands of dogs and cats every month, protecting lives and preventing unnecessary suffering before it starts.