Alfred M. Legendre1*, Tanya Kuritz2, Gina Galyon1, Vivian M. Baylor3 and Robert Eric Heidel4
1 Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA, 2 Sass & Sass,
Inc., Oak Ridge, TN, USA, 3 Independent Consultant, Oak Ridge, TN, USA, 4 Graduate School of Medicine, University of
Tennessee, Knoxville, TN, USA
Feline infectious peritonitis (FIP) is a fatal disease with no clinically effective treatment.
This field study evaluated treatment with Polyprenyl Immunostimulant (PI) in cats with
the non-effusive form of FIP. Because immune suppression is a major component in
the pathology of FIP, we hypothesized that treatment with an immune system stimulant
would increase survival times of cats with dry FIP. Sixty cats, diagnosed with dry FIP
by primary care and specialist veterinarians and meeting the acceptance criteria, were
treated with PI without intentional selection of less severe cases. The survival time from
the start of PI treatment in cats diagnosed with dry FIP showed that of the 60 cats with
dry FIP treated with PI, 8 survived over 200 days, and 4 of 60 survived over 300 days.
A literature search identified 59 cats with non-effusive or dry FIP; no cat with only dry
FIP lived longer than 200 days. Veterinarians of cats treated with PI that survived over
30 days reported improvements in clinical signs and behavior. The survival times in our
study were significantly longer in cats who were not treated with corticosteroids concurrently
with PI. While not a cure, PI shows promise in the treatment of dry form FIP, but a
controlled study will be needed to verify the benefit.
Keywords: feline infectious peritonitis, Polyprenyl Immunostimulant, increased survival, chronic disease, feline coronavirus, field study