Kitty colds: Living with Feline Herpes virus

Almost all kittens and cats are exposed to feline herpes virus (FHV-1). Some will develop effective immunity against it and others will become carriers of the virus. FHV-1 will commonly go into a latent state and hide within the nervous system and not cause any disease. During times of physical or environmental stress, as well as times with no apparent trigger, the virus will reactivate and cause clinical signs. Unfortunately, there is no complete cure for herpes virus.

Clinical Signs

Signs of infection may include fever, decreased appetite, sneezing, coughing, discharge from the eyes and nose; swollen, red and squinty eyes and corneal ulcers. Symptoms can range from mild to severe and can be present for several weeks during an outbreak. In some cats, chronic, recurrent or severe infection leads to structural damage in the nose and will have a persistent nasal discharge and chronic sneezing that may or may not be controlled with antibiotics. In others, chronic eye ulceration can occur. These problems often require life-long therapy to control symptoms.

Diagnostic Testing

Feline Herpes virus is generally diagnosed based on history and clinical signs. Testing that may be needed in some cases include eye diagnostics such as Schirmer tear tests, fluorescein stain test and conjunctival swabs for cytology, culture or PCR assays. Blood tests such as complete blood count and serum assays for specific organisms may also be considered. 


There are several options for therapy which is tailored to the specific signs your cat is experiencing. 

  • L-lysine is an amino acid oral supplement that is thought to decrease the frequency and severity of clinical disease when administered prior to the onset of disease. Cats with recurrent herpes infection should remain on Lysine indefinitely. There are some cats who cannot be on Lysine due to GI upset. 
  • Eye medications such as antibiotic ointments, and/or anti-viral drops may be needed in cats with eye discharge or conjunctival swelling.
  • Since FHV-1 is a virus, antibiotics are NOT needed in most cases. Antibiotics may be prescribed if secondary bacterial infection is suspected or if other infectious organisms are involved.  
  • Appetite enhancements are often needed in cats with this problem. Many cats with nasal congestion cannot smell very well and develop a picky appetite or quit eating altogether. Offering palatable, smelly food and presenting it warm and fresh will help encourage eating. Appetite stimulants may also be considered.
  • Finally, oral anti-viral medications such as famciclovir can be considered.


Minimizing environmental stress, maintaining a consistent daily routine and preventing exposure to sick cats can help limit the frequency of outbreaks. Routine vaccination of kittens and cats for herpes virus and calicivirus can help prevent severe illness from these specific upper respiratory viruses. 

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