What is Feline Herpesvirus?
Feline Herpesvirus (FHV) is a highly contagious viral disease that affects over 90% of the world’s cat population. It is primarily spread through respiratory secretions, with most infections occurring when kittens contract the virus from their mother (queen).
One of the unique traits of this virus is its ability to hide from the immune system, making it impossible to completely eliminate from the body. Once a kitten is infected, the virus often remains dormant until periods of stress, at which point it reactivates and rapidly replicates on the surfaces of the eye (cornea and conjunctiva). This can lead to inflammation, irritation, and even ulceration of the eye.
Because the virus remains in the body for life, flare-ups can occur at any time of stress, meaning a cat may experience recurrent symptoms throughout its life.
Can Humans Catch Herpesvirus from Cats?
No, feline herpesvirus (FHV) is not transmissible to humans, and cats cannot contract human herpesvirus either. While you may be familiar with the human herpesvirus that causes cold sores, it behaves similarly to feline herpesvirus in that it remains dormant in the body and reactivates during times of stress. However, these are species-specific viruses, meaning they do not cross between humans and cats.
How Is Feline Herpesvirus Diagnosed?
Feline Herpesvirus (FHV-1) is often diagnosed based on clinical signs and history, as its presentation is typically recognizable. A thorough eye examination, along with a detailed medical history, can usually confirm the suspicion of FHV-1 infection. To assess the active state of the disease, veterinarians may apply special eye stains to detect corneal ulcers or inflammation caused by the virus.
Although viral testing is available, it is generally not reliable for diagnosing FHV-1.
This is because:
- False negatives can occur due to the virus’s intermittent activation and shedding.
- False positives may result from prior vaccination, which can show viral DNA without an active infection.
For these reasons, diagnosis is primarily based on clinical evaluation rather than laboratory tests.
Why Does My Cat Have Herpesvirus if It Was Vaccinated?
Your cat likely contracted feline herpesvirus (FHV-1) from its mother before vaccination. Since herpesvirus can hide in the body, it remained dormant until a stressful event triggered it to reactivate. The FHV-1 vaccine does not eliminate the virus; instead, it helps reduce the severity of symptoms if your cat is exposed to a new infection. However, because your cat was already carrying the virus before vaccination, the vaccine could not prevent future flare-ups.
What are the signs of herpesvirus?
Feline herpesvirus (FHV-1) can cause a range of clinical signs, most commonly affecting the eyes and respiratory system.
Eye-Related Symptoms:
- Eye discomfort (squinting or rubbing)
- Excessive eye discharge (watery or thick mucus)
- Swelling and redness of the conjunctiva (conjunctivitis)
- Corneal ulcers, which can be painful and affect vision
- One or both eyes may be affected, with one sometimes worse than the other
Respiratory Symptoms:
- Sneezing
- Nasal discharge (runny or snotty nose)
- Fast or labored breathing
Chronic Complications:
- In some cases, herpesvirus can lead to long-term eye problems, including:
- Symblepharon (fusion of the conjunctiva to the cornea or eyelid)
- Sequestrum (dead corneal tissue forming a dark plaque)
- Tear duct narrowing, leading to tear overflow
Symptoms may flare up during periods of stress, making lifelong management important for affected cats.
Can Feline Herpesvirus Be Cured?
No, feline herpesvirus (FHV-1) has no cure, as the virus remains dormant in the body and can reactivate during times of stress. Without treatment, recurring eye problems are common.
Managing the Disease: While the virus cannot be eliminated, treatment focuses on reducing the frequency and severity of flare-ups. With the right management, episodes can become infrequent or even almost nonexistent, and symptoms can be significantly milder.
Reducing Stress: Since stress is a major trigger for herpesvirus flare-ups, minimising stress in your cat’s environment is one of the most effective ways to manage the disease. Speak with your veterinarian for advice on stress reduction strategies tailored to your cat’s needs.
With proper treatment and care, feline herpesvirus can be well-managed, allowing your cat to live a happy and comfortable life.
Best Treatment for Feline Herpesvirus
The most effective treatment includes antiviral medication and pain relief, available as oral tablets or eye drops. Our ophthalmologists will determine the best option for your cat while also focusing on minimising stress, which can trigger flare-ups.