Is Lysine Use for Cats with URI beneficial?

Last updated: 2018-03-08
Document type: FAQs
Topics: Shelter Population Management, Infectious Disease, Community Cat Resources
Species: Feline

While lysine supplementation for feline URI has been commonplace for many years, a 2015 study reviewing existing literature showed no evidence of benefit. Dr. Wilson shares this and other interventions that are likely to be more helpful when dealing with feline URI in a shelter.



Is L-lysine is of any use in preventing or treating URI in cats?




The use of lysine to prevent and treat URI in cats is a very interesting topic. While initial research seemed to indicate that it would be helpful, newer information suggests that, unfortunately, lysine really does not do much to help cats avoid illness, recover faster or minimize clinical signs. This 2015 article by Bol and Bunnick reviewed the existing literature to date on the use of lysine for feline URI.


Based on these newer reports, we are not currently recommending the use of lysine to prevent or treat URI in shelters.


There are other steps to take to minimize URI in an animal shelter. As we know, stress is one of the biggest risk factors for the development of clinical signs of feline respiratory disease. One of the most important ways to decrease stress is to ensure that all cats, at all times, in the shelter have adequate housing. This includes:  > 9 square feet of space per cat in individual housing and > 18 square feet floor space per cat in group housing, double-sided housing, soft bedding, places to hide, scratching surfaces. A study by Wagner et al found that in addition to enough space in their housing unit, fewer than 2 moves (in and out of a cage or between cages) during the first week in shelter reduced the risk of a cat developing URI.  If a cat is adoption ready upon intake, going directly into adoption housing will be the most direct and thus best pathway for that cat to maintain welfare and good health.


Preventing crowding is also tremendously important, both to limit cats’ exposure to disease-causing agents, and to reduce stress. Moving cats through your shelter and into homes as quickly as possible is essential to keeping animals healthy, as decreasing length-of-stay will decrease stress, which in turn will help to limit URIs.


For more information about URI in cats please visit our Feline Upper Respiratory Infection Information Sheet


Please let us know if you have any further questions or concerns!


University of Wisconsin Shelter Medicine Program

Erin Wilson, DVM
Outreach Veterinarian
Shelter Medicine Program
University of Wisconsin – School of Veterinary Medicine

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