Feline Herpesvirus

If your cat develops signs of an upper respiratory infection, it could easily be caused by feline herpesvirus. This viral infection, although highly contagious among felines, is species-specific. This means you don’t need to worry about catching it. If your cat is unlucky enough to get it, there are some important steps you can take to help it recover and prevent its spread.

What Is Feline Herpesvirus?

Feline herpesvirus is more correctly referred to as feline herpesvirus type-1, and it can cause a disease process known as feline viral rhinotracheitis. Unfortunately, this virus is easily spread between cats because it can be transmitted through droplets, from nasal secretions to saliva. If you have multiple cats and one is shedding the virus, your other kitties can also get it. E.g. from sharing food or water containers, litter boxes, bedding, and even you!

Symptoms

Cats that are actively infected with feline herpesvirus typically have upper respiratory illness symptoms, including:

• Sneezing
• Watery eyes
• Lethargy and depression
• Lack of appetite

Unfortunately, affected cats may also be affected by conjunctivitis or inflammation of the tissues around their eyes. In some cats, this may lead to ulcers on the surface of the cornea, scarring, and even dry eye, or keratoconjunctivitis sicca (KCS).

Secondary effects

Secondary bacterial infections can develop in cats with the feline herpes virus. This may lead to worsening upper respiratory signs, thick, mucoid discharge, and even lower respiratory signs, such as pneumonia, although that is less common. While this virus only affects cats, some bacterial infections that can take root in infected kitties may be contagious (or zoonotic) to humans. 

A large portion of the feline population has been exposed to feline herpesvirus, and many are only mildly affected. Young kittens, who may be exposed to an infected mother, are particularly at risk for devastating consequences, and intensive supportive care may be needed to help them pull through. 

Occurrence and Testing of Herpesvirus

While many cats can show signs of the feline herpes virus, most will recover uneventfully. Once a cat has been infected with the virus, it may become dormant or latent in their system. Stressors, such as new family members or moving, can trigger them to have another active infection. 

In many cases of feline herpesvirus, veterinarians will make a presumptive diagnosis based upon the cat’s history and clinical signs. Such as a new stressor or change in the household including getting a new cat. Ocular signs, such as discharge or corneal ulcers, can be a hallmark of this viral infection. Your veterinarian may, therefore, recommend testing such as a fluorescein eye stain, where a special dye is carefully applied to the eyes to look for corneal ulcers. 

More confirmatory testing of feline herpesvirus infections includes viral PCR testing. Sterile swabs are generally collected from the conjunctiva of the eye, the back of the throat, and possibly of nasal secretions. In cats that are already in the process of recovering from the infection, these tests may be negative. Moreover, they do not identify a carrier state. 

Treatment of Feline Herpesvirus

If your cat is diagnosed with the feline herpesvirus, treatment generally consists of supportive therapies. Cats that are reluctant to eat may be offered different foods or carefully heated up canned food. This makes it more palatable since they often have trouble smelling.

Antibiotics may be used to treat or prevent secondary bacterial infections. However, they are not effective against the virus itself. 

Some cats need antiviral therapy, particularly if they have recurrent infections. The most common medication used is famciclovir. Amino acid supplementation with lysine is effective at reducing the viral cycle in some cats. Furthermore, it may reduce the re-occurrence of symptoms. Certain probiotics, such as Fortiflora, have also been noted to improve the course of illness.

Many cats develop eye issues when they are infected with the feline herpesvirus Thus, your veterinarian may recommend antibiotic ocular medications. They treat corneal ulcers, as well as eye lubricants to help with decreased tear production. 

For cats that are congested, you may find that they benefit well from humidifying therapies. The simplest way to do this is to bring them into the bathroom with the shower running. It provides a moist, steamy environment.

Prevention of Feline Herpesvirus

Because feline herpesvirus is so widespread, it is very difficult to prevent infection. Especially when so many pet owners are getting cats from rescue situations where their histories are unknown (or can’t be changed). The good news is that vaccines that can help protect your cats are available.

Depending on where you live and what the vaccine manufacturer’s label guidelines are, the vaccine is generally effective for 1 or 3 years after it has been appropriately boostered. High-risk cats may need to get the vaccine more frequently as immunity may wane over time.

New feline additions to the household should be quarantined before being introduced to the family. Sick cats should be separated from other cats. Any materials that may have been exposed should be decontaminated. For example, washing bedding in the washing machine with detergents or sanitizing all dishes and litter pans with disinfectants. The virus does not last long in the environment. Yet, moist secretions can harbor the virus. 

In Summary

Feline herpesvirus is a common infection in cats, typically characterized by upper respiratory-type symptoms. Vaccinating your cats can help reduce transmission, as well as symptoms. Additionally, your veterinarian can make appropriate suggestions based upon your cat’s lifestyle.