Microcytosis was common and can increase suspicion of FIP in the presence of other typical clinical and laboratory abnormalities. The low prevalence of lymphopenia in cats without effusion suggests that this is not a useful parameter in non-effusive FIP. The frequent occurrence of a left shift in the absence of a mature neutrophilia complicates the differentiation of effusive FIP and septic peritonitis. Globulins and A:G ratio were of higher diagnostic value than hyperproteinaemia.

Background: There is no therapy with proven efficacy to treat cats with feline infectious peritonitis (FIP). Hypothesis: Feline interferon‐omega (FeIFN‐ω) prolongs survival time and increases quality of life in cats with FIP. Animals: Thirty‐seven privately owned cats were subjects of this study. Methods: The study was performed as a placebo‐controlled double‐blind trial. Feline infectious peritonitis was confirmed by histology or immunostaining of feline coronavirus (FCoV) antigen in effusion or tissue macrophages or both. The cats were randomly selected for treatment with either FeIFN‐to or a placebo. All cats received adjunctive treatment with glucocorticoids and antibiotics and passive immunization with Feliserin. Results: There was no statistically significant difference in the survival time of cats treated with FeIFN‐ω versus placebo or in any other variable evaluated (with the exception of the lymphocyte count). The cats survived between 3 and 200 days (median, 9 days). There was only 1 long‐term survivor (>3 months), and the cat was in the FeIFN‐ω group. Conclusion and Clinical Relevance: No effect of FeIFN‐ω on survival time or quality of life could be demonstrated in this study.

Feline infectious peritonitis (FIP) infection resulting in clinical signs is invariably fatal despite clinical intervention. As FIP is an immune-mediated disease, treatment is mainly aimed at controlling the immune response triggered by the infection with the feline coronavirus (FCoV). Immune suppressive drugs such as prednisone or cyclophosphamide may slow disease progression but do not produce a cure. In nearly every published case report of attempted therapy for clinical FIP, glucocorticoids have been used; there are, however, no controlled studies that evaluate the effect of glucocorticoids as a therapy for FIP. Some veterinarians prescribe immune modulators to treat cats with FIP with no documented controlled evidence of efficacy. It has been suggested that these agents may benefit infected animals by restoring compromised immune function, thereby allowing the patient to control viral burden and recover from clinical signs. However, a non-specific stimulation of the immune system may be contraindicated as clinical signs develop and progress as a result of an immune-mediated response to the mutated FCoV.

Background: Currently there is no drug proven to effectively treat cats with feline infectious peritonitis (FIP). Hypothesis: Propentofylline (PPF) can decrease vasculitis, and therefore prolong survival time in cats with FIP, and increase their quality of life.Animals: Twenty-three privately owned cats with FIP. Methods: Placebo-controlled double-blind trial. FIP was confirmed by histology or immunostaining of feline coronavirus (FCoV) antigen in effusion or tissue macrophages or both. The cats were randomly selected for treatment with either PPF or placebo. All cats received additional treatment with glucocorticoids, antibiotics, and low molecular weight heparin according to methods.Results: There was no statistically significant difference in the survival time of cats treated with PPF (8 days, 95% CI 5.4-10.6) versus placebo (7.5 days, 95% CI 4.4-9.6). The median survival time of all cats was 8 days (4-36 days). There was neither a difference in quality of life (day 7, P = .892), in the amount of effusion (day 7, P = .710), the tumor necrosis factor-alpha (TNF-a) concentration (day 7, P = .355), nor in any other variable investigated in this study, including a complete blood count, and a small animal biochemistry profile.Conclusions and Clinical Importance: This study did not detect an effect of PPF on the survival time, the quality of life, or any clinical or laboratory parameter in cats with FIP. Therefore, PPF does not appear to be an effective treatment option in cats with a late stage of the disease FIP.

No effect of FeIFN-omega on survival time or quality of life could be demonstrated in this study.