Herpesvirus in cats

What is feline herpes?

Feline rhinotracheitis, or as it's more commonly known, feline herpesvirus (FHV), is a very common and contagious virus that can be contracted by cats and kittens. Together with feline calicivirus (explained below), it is one of the most common causes of conjunctivitis and "cat flu."

What are the symptoms of feline herpes?

Depending on the severity of the virus and infection, symptoms will vary. Cats with FHV might suffer from ocular (eye) symptoms like conjunctivitis but if they develop an upper respiratory infection as a result of the virus, they may also suffer respiratory issues. Symptoms can include:

• Conjunctivitis—inflammation or swelling of the eye tissue, often referred to as "pink eye"
• Nasal and ocular discharge—mucus flowing from your cat or kitten's nose or eyes
• Excessive blinking
• Sneezing — often caused by an upper respiratory infection (URI)
• Keratitis - inflammation of the cornea which can lead to corneal ulcers
• Fever and lethargy— other non-specific symptoms of a URI caused by feline herpes

Feline rhinotracheitis can be very severe, especially in  kittens. It's vital that you contact your vet if you notice any of the above symptoms, as well as ensure that your kitten receives the vaccine at the right time as part of an appropriate vaccination schedule.

What is the difference between feline herpesvirus and feline calicivirus?

Feline herpesvirus and feline calicivirus (FCV) are different viruses with differing symptoms. Some of the common symptoms of FCV, for example, include mouth ulcers and gingivitis as well as nasal discharge.

These two viruses are quite different, but the confusion comes from the fact that they are often both linked to cat flu.

The symptoms of cat flu include eye infections (conjunctivitis, discharge) and/or nasal discharge and/or mouth inflammation and ulcers. Cat flu may be caused by different pathogenic agents: including both herpesvirus and calicivirus but also bacteria like Chlamydia felis.

Are there any species or age groups more at risk of FHV?

All cats can catch the feline herpesvirus, but kittens who have not been vaccinated are particularly susceptible to catching the virus. If you have a fully grown, adult cat who has been vaccinated, they can still catch the virus but their symptoms should not be as severe. Feline herpesvirus is not usually contagious to humans or other pets like dogs.

How do cats get feline herpes?

Like most other viruses, cats catch the feline herpesvirus directly from other cats. Infection can also come from saliva, or from nasal or oral discharge - two of the symptoms of feline herpesvirus. 

Is feline herpes contagious?

Feline herpes is a highly contagious virus that can easily be passed between cats. While close contact between cats is the most common reason for infection, it's still important that you regularly clean any areas of your home where cats spend a lot of time.

Thankfully, when the virus is found in a specific place or environment, such as in the home or a kennel, it only has a low level of resistance. This means it can be removed easily with common disinfectants. The virus cannot be transmitted to humans or other animals.

Due to the virus being latent, your kitten or cat could be exposed when in contact with other cats that seem healthy. The healthy-looking cat carrying the disease may therefore be a risk to the other members of the cat population. This is especially so in the case of kittens.

How is FHV diagnosed?

FHV is so common that your vet may be able to prescribe treatment just from their symptoms. However, to have a conclusive diagnosis, they'll need to test your cat or kitten. Your vet will take swabs of any discharge from their nose, mouth or eyes and send the sample to a laboratory to confirm the presence of the virus. Unlike tests for Feline Immunodeficiency Virus (FIV), blood tests are not required.

What is the life expectancy for a cat with feline herpesvirus?

Most cats fully recover from an infection related to herpesvirus, although they can be fatal or cause long-term issues with kittens and other vulnerable cats. Once infected with feline herpes, cats become carriers for the rest of their lives. However, that doesn't mean they'll show symptoms.

Treatment for feline herpesvirus

There is no cure for feline herpesvirus, in which case treatment will be focused on supportive care while the virus is active - which is generally around 10 days. Supportive care during this period may include:

Antibiotics: will not attack the herpesvirus itself but may be used for any secondary infections.

Topical medication: this may be used on the eyes to reduce symptoms of ocular discharge.

How to prevent feline herpesvirus

To help prevent your cat from becoming infected with herpesvirus or from further infecting other cats, you should:

Vaccinate your cats: While vaccination doesn't mean your cat can't catch the feline herpesvirus, it does drastically reduce the risk. That means they'll suffer more minor symptoms and be less contagious to others.

Keep shared spaces clean: If you have shared spaces where cats interact with each other, or where an infected cat spends a lot of time, make sure to disinfect surfaces to avoid contamination.

Wash your hands: After petting your cat (or any other cat), it's important to wash your hands to avoid unintentionally passing on the feline herpesvirus to other cats. While humans are not usually susceptible to the virus, they can pass it on to cats through contact.

Management of feline herpesvirus

If your cat recovers from the active phase of the virus, they will likely go on to live a normal life - even if they are still a carrier. You can reduce the risk of the virus reoccurring by reducing stress and creating a calm environment for your cat to live in. Secondary illnesses and infections can also trigger the virus to flare up again. To avoid your cat becoming ill, ensure they have a good diet and aren't at risk of contamination from other cats.

Is there a feline herpes vaccine?

Your kitten should be vaccinated against the feline herpesvirus as one of the core vaccines they must have early on in their development.  The core recommended vaccinations for kittens include:

• FVRCP: to protect against Feline distemper (FPV), Feline calicivirus (FCV) and Feline herpesvirus type I (FHV-1)
• Rabies: to protect against the Rabies Virus (RV)

The American Animal Hospital Association recommends that initial vaccinations for the core vaccines should be given to kittens between 6-8 weeks of age.

Speak to your vet and they will put in place a kitten vaccination program including all the core vaccines and any other recommended vaccines depending on your kitten's lifestyle and environment.