Feline Infectious Peritonitis (FIP) is a disease that kills 1 in 100 to 1 in 300 of all cats under ages 3-5. The incidence can be five to 10 times greater among young cats coming from catteries and shelters. FIP is virtually 100% fatal, and there is no treatment or cure. FIP can manifest suddenly -- weeks, months or even years after initial infection. Therefore, cat lovers usually experience the heartbreak of this disease long after they have developed strong emotional bonds with their pets.

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  • Toby

  • Center for Companion Animal Health

  • Aziza

  • Coronavirus

    Coronavirus in cell cultures

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  • Redman

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  • Rusty

  • Saffron

  • Dr. Niels C. Pedersen

  • Dr. Niels C. Pedersen

  • Dr. Pedersen and SOCK FIP Volunteers

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  • Smiley

    His smile was his umbrella, but it didn't stop FIP.

  • Lucy

Dr. Pedersen 2015 Research Summary

December 25, 2015

Dear SOCK FIP supporters:

Your support of FIP research at the Center for Companion Animal Health (CCAH) over this last year has been tremendous and much appreciated. This last year has seen a number of advances in our knowledge of FIP and eventual cures. We documented that many cats have a natural resistance to FIP virus, but this resistance increases with age and cannot be explained by simple genetic differences. Rather, resistance is what we call polygenic, and involves many different genetic pathways, any one of which can be used in a given cat at a given time to eliminate the infection. Our research also indicates this immunity is not always permanent and some cats can become susceptible that were once resistant. We learned inbreeding is one of the most important genetic causes of decreased resistance to FIP. We also discovered that the FIP virus attacks only a single cell in the body, a peritoneal-type macrophage, and the infection spreads from macrophage to macrophage and not as free virus in the blood. Virus infected macrophages spread the infection to other organs, and can even enter the brain and eyes in some cats and cause neurologic or ocular disease. Infected macrophages in cats destined to develop FIP also cause a generalized suppression of normal immunity through some sort of signaling, thus assuring the virus’ own survival. Cats that are resistant to FIP do not manifest this suppression.

Finally, and probably of most importance, is our work with antiviral drugs. I am engaged in research with Dr. Yunjeong Kim and her team at Kansas State University on testing a new antiviral drug that strongly suppresses FIP virus replication. This research has gone so well that we will be starting a field trial at UC Davis in late January or February with funds provided by Morris Animal Foundation. This trial will be limited to 70 owned cats with naturally occurring FIP, mainly with wet FIP and a few select cases of dry FIP. Details of this trial will be made public when the time comes to recruit cases for the study. If this drug proves effective against naturally occurring FIP, it will hopefully be taken up by industry and put forward for FDA approval.

I have the fortune of bringing Dr. Brian Murphy, Dr. Chrissy Eckstrand and Dr. Patty Pesavento into our FIP research team. Dr. Pesavento and Dr. Eckstrand will research a highly sensitive test to detect FIP virus with funds from the CCAH that were gifted for FIP research. Dr. Murphy is principal investigator, and I am co-investigator, on a grant from the Winn Feline Foundation to test drugs against FIP virus that are being developed by a leading pharmaceutical company against related coronaviruses causing SARS and MERS in humans. Preliminary studies indicate that many of these drugs will also be active against FIP virus. Therefore, we have entered a new era that might finally see a cure for cats suffering from FIP. The hope is to treat FIP in a manner similar to how antiviral drugs are used to cure people of hepatitis C virus infection.

I have been researching FIP for over 50 years and conclude that this disease is the most complex infection known to man or animal. It has been a tough slog, but we finally understand most of the mysteries of how a ubiquitous and largely innocuous intestinal coronavirus can end up causing such a devastating disease as FIP. There is finally light at the end of the tunnel. Thank you again for your support and patience and have a merry holiday season and we all look forward to good things in 2016.


Dr. Niels C. Pedersen and colleagues at the UC Davis School of Veterinary Medicine