Viral diseases

Feline Calicivirus

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: February 22, 2018
Feline Calicivirus

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At Animal Wised we want what's best for your pet, that's why we try to cover all diseases, ailments and strange behaviors that can occur in your furry friend.

This time we will discuss feline calicivirus and its symptoms and treatment. This is because this disease is very common among cats and can be dangerous for them if not detected early.

Remember, you should never medicate your pet yourself. Consult your veterinarian if you notice any symptoms or unusual behavior. And give your little friend all the love, care and food they need to be a strong, healthy and happy animal.

  1. What is feline calicivirus?
  2. Why is Feline Calicivirus risky?
  3. How is it transmitted?
  4. Symptoms of feline calciviruses
  5. What is the diagnosis?
  6. Treatment of feline calciviruses
  7. Prevention

What is feline calicivirus?

It is a highly infectious disease that usually affects large groups of cats, because of how easily the virus is transmitted. However, it can also affect house cats.

Calicivirus (FCV) is a type of cat flu. It manifests as an acute respiratory illness, affecting the cat's upper tract and can cause sinusitis and rhinitis. The virus belongs to the Caliciviridae family, from the Vesivirus genus.

Even when they seem to have been cured, affected cats can become healthy carriers, which is where lies the high level of transmission of this disease.

Feline Calicivirus - What is feline calicivirus?

Why is Feline Calicivirus risky?

Feline calicivirus is a virus with an infectious strain which can easily mutate. This means, the same strain adapts and changes according to its environment and demands that this presents. As a consequence, the virus develops small variations.

These variations have resulted in the existence of a large number of strains of this disease. This makes it difficult to accurately identify and prevent.

Furthermore, even cats vaccinated against the virus can get it, given its capability of mutating. Of course, vaccinating considerably reduces the chances, which is why it is considered mandatory.

It is very common in groups of wild cats or in shelters because it spreads very easily. However, if your house cat has access to the outside, there is also possibility of infection, which can infect other cats in the household if there are any.

In addition, your cat may sometimes contract this virus chronically, or even become the carrier. This means that they will not present any symptoms or discomfort, but can transmit the disease to other cats.

How is it transmitted?

The main route of transmission is through direct contact with infected cats or carriers, as it is transported in saliva and feces, although in small amounts.

The most common route of infection occurs through objects or spaces the infected cat usually uses. It involves contact with the animal's fluids, such as feeders, toys and litter products. This is because bacteria can survive in these areas for up to 28 days.

Young cats, animals living on the street, old cats and immunosuppressed cats are more likely to contract the virus. However, any cat can become infected with the virus, so it is important to keep vaccines up to date and give your cat the care they need in order to prevent infection.

It is important to note that this virus is not contagious to humans or dogs.

Feline Calicivirus - How is it transmitted?

Symptoms of feline calciviruses

Feline calivicirus is a respiratory disease. The virus enters the animal through the mouth or nose, staying in lymphoid tissue that corresponds to the oropharynx, affecting the lungs. The symptoms are:

  • Colds
  • Sneezing
  • Mucus
  • Conjunctivitis
  • Ulcers on the palate
  • Ulcers in the oral mucosa
  • Ulcers in the nose
  • Depression

The disease can get worse, causing pneumonia and arthritis, but only in rare cases. Some strains cause fever and lameness.

Symptoms usually appear 2 to 10 days after the disease is contracted. The pain of mouth ulcers can cause the cat to stop eating. Conjunctivitis can also cause corneal ulcers, due to the efforts of the animal scratching.

The maximum cycle of the virus lasts four weeks and most cats recover, although there are healthy carriers and chronic cases. Approximately 80% of cats stop spreading the virus 75 days after being cured. However the other 20% become healthy carriers for years, or even for the rest of their lives.

In recent years a more virulent and dangerous strain of this virus has been discovered, called VS-FCV, virulent systemic feline calicivirus. The symptoms are in addition to those already mentioned:

  • Jaundice (yellow skin)
  • Swelling of the face and extremities
  • Ulcers on footpads, nose, mouth and ears
  • Hair loss
  • Gingivitis
  • Stomatitis

If not treated early and adequately, the virus can cause death.

What is the diagnosis?

Mainly, symptoms will let you know whether it is a case of feline calicivirus, especially when ulcers in the animal's mouth appear. However, laboratory tests are performed on tissue cultures from the oropharyngeal mucosa.

Feline Calicivirus - What is the diagnosis?

Treatment of feline calciviruses

Once the presence of the virus has been confirmed and the strain identified, treatment should be prescribed. There is not a drug as such that annihilates the virus, but remedies that provide the animal with support throughout the disease cycle are prescribed; allowing relief of symptoms and to prevent them from escalating.

Antibiotics for possible infections, medications to help the cat breathe better and painkillers for pain control are prescribed. In addition, antivirals are administered to control the effects the infection causes.

Hydration is extremely important, so first of all, fluid treatment according to medical criteria is prescribed.

If the cat refuses to eat because of the pain, it is recommended to provide soft and fragrant meals. Failing this, you should resort to assisted liquid feeding through a syringe, always taking care not to injure the animal or cause them any unnecessary stress.

Given the mucus secretion and tears, you need to help your cat and clean them regularly with a piece of wet cotton to prevent their discomfort and prevent possible complications due to bacteria.

Keep the cat in a comfortable, warm and draft-free environment, to get them off to a speedy recovery. It is also essential that the animal is kept isolated from other cats you may have at home, and prevent them from venturing outside.

Ask your veterinarian about the possibility of testing to rule out leukaemia and feline immunodeficiency, because cats suffering because these infections are likely to develop other illnesses more easily.


In pets, it is recommended to follow the vaccination schedule for kittens from when the vet tells you, and repeat the vaccines every year. Although this will not prevent them from contracting the virus one hundred percent, they will be more protected than other animals.

If you've rescued a stray cat, they must remain isolated from your other animals until you can perform the necessary laboratory tests to rule this and other diseases out.

If they are a rescue cat, vaccination is also paramount. Cats with confirmed feline calicivirus infection must be separated from the rest to prevent an epidemic. Each container must have their food and their own sandpit. You should regularly disinfect the objects your cat uses with products that eliminate the virus and are not harmful to the feline.

The people looking after the rescue cat must care for the sick animals. Finally, after caring for everyone else, wash your face and arms and change your clothes after handling those carrying the virus.

The area where the animals with calicivirus are isolated must have adequate ventilation, low humidity and cool temperatures. Spaces should be cleaned frequently.

The most important thing for the prevention of this disease, in addition to maintaining a vaccination regime, is to keep a strict hygiene routine to prevent it from spreading.

Feline Calicivirus - Prevention

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Feline Calicivirus, we recommend you visit our Viral diseases category.

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