What is feline herpes?
Also known as feline viral rhinotracheitis (FVR), feline herpes is an acute upper respiratory disease of cats caused by the feline herpesvirus type 1 or FHV-1.
Feline herpesvirus is the most common cause of upper respiratory disease in cats, it is more common in kittens, cats in stressed/overcrowded environments such as animal shelters and multi cat households. Kittens and older cats are more at risk than healthy adults, and are also at greater risk of dying. Once your cat becomes infected with the feline herpesvirus he will have it for life.
The first outbreak is usually the most severe. Once recovered, in the healthy cat the immune system usually manages to keep the virus in check, but there may be the occasional outbreak at times of stress (pregnancy, lactation, overcrowding, while boarding etc.) or sickness. Corticosteroid injections may also bring on an outbreak in the infected cat.
What is an upper respiratory disease?
An upper respiratory disease refers to infections in the area of the eyes, nose, throat and sinus areas.
What are the symptoms of feline herpes?
- Ocular (eye) and nasal discharge
- Conjunctivitis which sometimes lead to corneal ulcers
- Loss of appetite (anorexia)
- Ulceration of the mouth and tongue.
The virus infects and grows in nose, eyes, sinus, throat, mouth and tonsils of a cat which causes inflammation and fever. Due to the nasal discharge, the cat's sense of smell is severely diminished, causing it's appetite to wane. While loss of appetite is dangerous in all cats, it is especially so in kittens where anorexia and dehydration can quickly take hold.
Due to the damage caused to tissues, it is possible for a secondary bacterial infection to take hold.
If a pregnant cat catches herpes, it may lead to abortion of the kittens.
How do cats become infected?
In the nonreplicant or "latent" phase, the virus is still in the host cells but it is not causing disease at that time. They do not shed the virus to other cats.
Asymptomatic carriers may shed the virus. This means that while they are displaying no symptoms they are actively shedding the virus and other cats can become infected.
During the "active" phase, the virus interferes with the cell's normal metabolism, causing the symptoms associated with the disease. T he virus is shed and other cats can become infected.
In Utero: It is possible for feline herpesvirus to be passed onto unborn kittens via the mother.
Direct Contact: Feline herpesvirus is transmitted by oral and respiratory secretions of a cat who is actively shedding the virus.
Indirect Contact: Contact with infected food bowls, litter trays, bedding (fomites) etc., which have been in contact with an infected cat shedding the virus.
How is feline herpes diagnosed?
Your veterinarian will perform a physical examination of your cat. There are other diseases with similar symptoms to feline herpesvirus although there are some slight differences. For example calicivirus (which is also responsible for upper respiratory infections in cats) typically causes ulcers in the mouth, whereas feline herpesvirus causes ulcers in the eye.
Your veterinarian may take a swap which will be sent to a laboratory for PCR (polymerase chain reaction), which amplifies the virus greatly. It is however possible for a negative result, even though the cat has feline herpesvirus.
How is feline herpes treated?
- Keeping the nostrils and eyes clear of discharges. Use cotton balls dipped in warm water to wipe away any discharge.
- Antibiotics may be prescribed, these are ineffective against the herpes virus, but may be used to treat secondary infections that can occur.
- Antiviral drugs.
- Ensuring the cat is receiving food and liquid intake. Force feeding, IV fluids or sub cutaneous fluids if necessary.
- L-Lysine is an essential amino acid which has been shown to suppress viral replication and inhibit cytopathogenicity. However, you should always speak to your veterinarian before you supplement your cat's diet.
Can I catch herpes from my cat?
No, only domesticated cats and close relatives can catch feline herpesvirus. There are several types of herpes virus to infect humans but they are not the same as feline herpes.
Image courtesy of Nottingham Vet School