FIP Research and Development

Timeline and benchmarks

Feline Infectious Peritonitis (FIP) – a generally fatal feline disease – was a research interest of Dr. A.M. Legendre of the University of Tennessee-Knoxville. In 2003, Dr. Legendre suggested trying PI for FIP. His collaboration with Sass & Sass, Inc., which started with feline rhinotracheitis, was then expanded to include FIP in 2006.

Feline Infectious Peritonitis (FIP) is a devastating disease caused by a mutated form of feline coronavirus that triggers global immunity failure in a cat. FIP has long been considered an incurable, fatal disease. There are two main forms of FIP, effusive (wet) and non-effusive (dry). The way clinical FIP develops as an immune-mediated disease is unique, unlike any other viral disease of animals or humans. This interaction between the body’s own immune system and the virus is responsible for the disease. Once a cat develops clinical FIP involving one or more systems of the cat’s body, the disease is progressive and almost always fatal. The research focused on the non-effusive, “dry” form which causes a variety of pathologies, including pyogranulomatous inflammation in various organs.

Polyprenyl Immunostimulant Research and Development timeline & benchmarks (FIP.)

• 2006 | Research begins.

Dr. Legendre starts his first, pilot study with three naturally infected cats with FIP diagnosed through biopsy of lesions. The study was an attempt to assess if Polyprenyl Immunostimulant™ (PI) holds promise in FIP. Two cats had marked clinical signs, and one cat was asymptomatic and diagnosed during spay. All three cats with confirmed dry form of FIP survived for over one year. (In fact, one of those cats survived for over 14 years). The researchers published their findings in 2009. Based on the results of this study, Dr. Legendre and Sass & Sass, Inc. decided to continue collaboration on the use of Polyprenyl Immunostimulant™ (PI) in FIP patients.

• 2010-2011 | Nationwide Field Study with UTK.

Sass & Sass, Inc. in collaboration with UTK successfully conducted and completed a nationwide field study of efficiency of Polyprenyl Immunostimulant™ (PI) in naturally occurring cases of non-effusive Feline Infectious Peritonitis (FIP). The study was in paer sponsored by the Winn Feline Foundation's grant to Dr. Legendre. The study is opened to all cats with the dry form of FIP regardless of the severity of the disease, in order to get a fair representation of real-life situations in veterinary practices. The results are published in 2017(1). The study collaborators decide to advance Polyprenyl Immunostimulant™ (PI, PPI) to the next step by doing a study in compliance with all regulatory requirements (and restrictions) by the USDA.

• 2011-2012

Dr. Legendre presented his findings at the Winn Symposium in Reston, Va in 2011, ACVIM Meeting in New Orleans in May 2012, and the AAHA Meeting in Phoenix, AZ in 2013.

• 2017 | Successful registration of VetImmune PI ™ In Europe for FRV and FIP.

The collaboration of Sass & Sass, Inc. and Panda Plus s.r.o. in the Czech Republic leads to the registration of Polyprenyl Immunostimulant under the Czech label Vetimmune PI™. Panda Plus s.r.o. becomes the official distributor. The Institute for State Control of Veterinary Biologicals and Medicines of the Czech Republic, the regulatory authority, grants registration for support in the treatment of feline rhinotracheitis (a herpesvirus infection) and the non-effusive (dry) form of Feline Infectious Peritonitis (FIP).

• 2017-2020 | FIP study in the pipeline.

Consulting with the USDA, Sass & Sass, Inc. has been designing and is getting ready to conduct a new FIP efficacy study(2) but the plans were derailed by COVID-19. Sass & Sass, Inc. is preparing to start the study shortly.

(1) Results of research published in peer-reviewed journals cannot substantiate health claims and do not substitute government-regulated trials.

(2) Please note that under their ethics in clinical trials guidelines, Sass & Sass, Inc. believes that study animals should not be euthanized but should be provided a chance through adoption and be treated like any owned pet. Sass & Sass, Inc. does not purposely infect animals with fatal diseases and does not support any research that does.


115 A Flint Rd., Oak Ridge, TN 37830

Call Us



Write to us