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Feline Calicivirus: A Cat Upper Respiratory Infection

Reviewed by Missy Beall DVM, PhD on Friday, February 7, 2014
Posted January 08, 2014 in Cat Diseases & Conditions A-Z

Are you thinking of adding a new kitty to your home? Congratulations! 

However, if you have other cats at home, pay heed; before bringing your new kitten home to meet the others, make sure to talk with your veterinarian about the risks of calicivirus, and other upper respiratory infections (URIs) and the importance of isolating your new kitten from your other cats (typically for at least 5-7 days). I know it sounds tough, but it’s so you can protect your other cats at home.

Cats can easily transmit URIs, like calicivirus. URIs are the human equivalent of the common cold. Calicivirus and other feline URIs are highly contagious infections that can result in mild to severe clinical signs (especially in immunosuppressed or very young kittens). Causes for URIs in cats, besides calicivirus, include herpesvirus (FHV-1), Chlamydia, Mycoplasma, and Bordatella bronchiseptica (what causes kennel cough in dogs). Thankfully, none of these are transmissible to you.

Upper respiratory infections are more likely to occur under certain circumstances: crowded living conditions (e.g., shelters, catteries), unsanitary conditions (e.g., when poor disinfection or poor hygiene are allowed), or during times of exposure to affected cats where bodily fluids are being exchanged by contagious discharge from the eyes or nose (sneezing). I see calicivirus and URIs like it most often after a new kitten is introduced to the home – exposing the other cats; hence, my recommendation of quarantining new kittens for a few days. Your middle-aged or geriatric cat doesn’t want to deal with a cold!

Signs of calicivirus or other URIs include the following:

  • Nasal discharge (typically clear colored but may progress to pus-colored)
  • Sneezing
  • Inappetance/anorexia
  • Discharge from the eyes (typically clear colored but can progress to pus-colored)
  • Squinting of the eyes (which may be due to ulcers of the cornea)
  • Lethargy
  • Difficulty chewing food (due to ulcers on the tongue and in the mouth)
  • Drooling (due to ulcers on the tongue and in the mouth)
  • Pink eye signs (e.g., redness of the eyes due to secondary inflammation of the conjunctiva)
  • Ulcers in the mouth
  • Noisy breathing
  • Increased or difficulty breathing
  • Dehydration
  • Fever
  • Death (rare)

Treatment of calicivirus
While there’s no cure for calicivirus or any URI (just like the common cold), there are some things you can do to help alleviate the severity of clinical signs:

  • Keep discharge away from the eyes and nose by gently wiping it with a damp

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Justine has more than 18 years of experience in the veterinary industry and is a board-certified emergency critical care veterinary specialist and toxicologist as well as the CEO and founder of Vetgirl. She is also a founding member of IDEXX’s Pet Health Network team.