Feline Herpesvirus Infection in Cats

Feline herpesvirus, FHV, is found around the world in both domesticated and wild cats. Cats of all ages can become infected with the virus though it poses the greatest risk for young kittens and for pregnant cats. Persistent feline viral rhinotracheitis has been found to be a risk factor in the development of ocular problems.

Feline herpesvirus is a highly contagious virus that causes feline viral rhinotracheitis. Feline viral rhinotracheitis is an acute upper respiratory infection that is one of the most common infections in cats. Feline herpesvirus is also associated with several less common diseases, which include keratitis and feline herpesvirus-associated dermatitis. After recovery, feline herpesvirus typically becomes latent, though it stays with the cat for the remainder of his or her life. The virus may become reactivated due to stress or corticosteroid treatment, allowing it to be passed on to other cats.

Symptoms are typically strong during the initial infection and may recur in a lessened form if the latent virus becomes reactivated.

• Discharge from the nose or eyes
• Sudden sneezing "attacks"
• Conjunctivitis or “pinkeye”
• Keratitis (inflammation in the cornea)
• Watery eyes
• Pain in eyes
• Blurred vision
• Lesions around and in eye
• Eye ulcers
• Squinting
• Eye spasms that may result in the eye remaining closed
• Lack of appetite
• Weight loss
• Weakness
• Lethargy
• Fever
• Drooling
• Depression
• Loss of pregnancy
• Skin inflammation

Feline viral rhinotracheitis is caused by the transmission of the feline herpesvirus between cats. This most often occurs by:

• Contact with discharge from an infected cat's eyes, nose or mouth
• Living in a multi-cat household
• Sharing litter boxes
• Inhalation of sneeze droplets
• Sharing food bowls
• Contaminated bedding and grooming tools
• Poor nutrition
• Psychological or physical stress
• Poor ventilation
• Having a weakened immune system

The veterinarian will need the cat's complete health history, a list of the symptoms, and an approximate date when symptoms first began. The veterinarian will examine the cat, which will include taking its temperature, looking for signs of nasal and eye discharge and examining the cat's eyes for signs of conjunctivitis.

Lab tests, such as a urinalysis, a complete blood count and a biochemistry profile, will be done. These tests may indicate a low white blood cell count, which is temporary. The veterinarian may take a sample of the discharge from the nose or eyes. This sample will be sent to an outside lab where it will grow in a culture. The infection can also be diagnosed with a corneal scraping or a biopsy. A polymerase chain reaction (PCR) test may also be performed on the sample. This advanced test looks for genetic material found in the virus. An x-ray may be performed to look for changes in the nasal cavity as a result of a chronic infection.

Medications

Oral antibiotics and antiviral medications may be prescribed in order to alleviate symptoms and prevent or treat secondary bacterial infections. Ophthalmic antibiotic or antiviral drops or creams may also be prescribed for conjunctivitis or other eye infections that resulted from the feline herpesvirus. If the cat is severely congested, mucolytic drugs may be prescribed to help break down the mucus and aid in breathing.

Fluid Therapy

Cats who are severely dehydrated due to refusing to eat or drink may need to be hospitalized in order to receive intravenous fluid therapy and nutritional support. During the hospital stay, labs will be done in order to ensure that the organs are reacting properly to the fluids.

Nebulisation

Cats who are having breathing difficulties may receive nebulisation with saline. A mask will be placed over the cat's mouth and nose while a machine called a nebulizer produces a saline mist. The cat will inhale the mist, helping to clear the nasal passages.

At-Home Care

The cat will need tender care at home. Foods may need to be blended and presented warm in order to entice the cat to eat. Frequent fluids will need to be offered in order to prevent dehydration from occurring.

As both physical and psychological stress can cause a dormant virus to become reactivated, it's important to remove stressors from the cat's environment, such as young children and other animals. While the cat is recovering, the cat should be isolated from other household cats in order to prevent feline herpesvirus from being spread. Proper nutrition will help the cat to recover from the infection faster. Refusal to eat or drink will require a prompt return to the veterinarian to prevent the condition from becoming fatal. Young kittens in the home can receive a vaccination to prevent the virus. This vaccine is typically given at nine and 12 weeks of age, with yearly boosters being administered to cats who are at-risk.