Pericardial effusion as a manifestation of feline infectious peritonitis

Łukasz Mazurek; Stanisław Winiarczyk; Łukasz Adaszek; Katarzyna Michalak; Dorota Pietras-Ożga

doi:10.2478/jvetres-2026-0039

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Pericardial effusion as a manifestation of feline infectious peritonitis

Journal of Veterinary Research

AHEAD OF PRINT

By: Łukasz Mazurek , Stanisław Winiarczyk , Łukasz Adaszek , Katarzyna Michalak and Dorota Pietras-Ożga

Open Access

|Aug 2026

Abstract

Introduction

Feline infectious peritonitis (FIP) is a fatal disease caused by feline coronavirus, most commonly associated with effusions in body cavities, while pericardial involvement remains rarely described.

Material and Methods

A three-year clinical study (2021–2024) included 256 cats with PCR-confirmed effusive FIP, of which 37 presented fluid accumulation exclusively in the pericardial sac. Diagnosis was based on real-time PCR analysis of pericardial fluid, echocardiographic examination and measurement of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations.

Results

Mutant feline coronavirus RNA was detected in pericardial fluid samples from all cats, with threshold cycle values ranging from 22 to 26 and highly specific PCR amplification confirmed by consistent melting temperatures (81.0–81.2°C). Ultrasonography revealed pericardial effusion in all 37 cats, with cardiac tamponade observed in 27% of cases and significantly higher NT-proBNP concentrations in affected individuals. Statistical analyses showed no significant associations between breed, age or sex and the occurrence of pericardial effusion, cardiac tamponade or NT-proBNP serum concentrations.

Conclusion

Pericardial effusion and cardiac tamponade may represent under-recognised manifestations of effusive FIP. Routine echocardiographic evaluation and molecular analysis of pericardial fluid should be considered in cats with suspected FIP and cardiopulmonary signs.

References

Adaszek Ł., Kalinowski M., Rutkowska-Szulczyk M., Mazurek Ł., Szulc D., Staniec M., Pietras-Ożga D., Michalak K., Buczek K., Winiarczyk S.: Comparison of the sensitivity of rapid tests FCoV Ab and PCR in the diagnosis of feline infectious peritonitis. Med Weter 2023, 79, 130–133, doi: 10.21521/mw.6745.
Open DOI Search in Google Scholar Back to article
Addie D.D., Belák S., Boucraut-Baralon C., Egberink H., Frymus T., Gruffydd-Jones T., Hartmann K., Hosie M.J., Lloret A‥ Lutz H., Marsilio F., Pennisi M.G., Radford A.D., Thiry E., Truyen U., Horzinek M.C.: Feline infectious peritonitis: ABCD guidelines on prevention and management. J Feline Med Surg 2009, 11, 594–604, doi: 10.1016/j.jfms.2009.05.008.
Open DOI Search in Google Scholar Back to article
Chang H.W., de Groot R.J., Egberink H.F., Rottier P.J.: Feline infectious peritonitis: insights into feline coronavirus pathobiogenesis and epidemiology based on genetic analysis of the viral 3c gene. J Gen Virol 2010, 91, 415–420, doi: 10.1099/vir.0.016485-0.
Open DOI Search in Google Scholar Back to article
Gorbalenya A.E., Enjuanes L., Ziebuhr J., Snijder E.J.: Nidovirales: evolving the largest RNA virus genome. Virus Res 2006, 117, 17–37, doi: 10.1016/j.virusres.2006.01.017.
Open DOI Search in Google Scholar Back to article
Kipar A., Meli M.L., Baptiste K.E., Bowker L.J., Lutz H.: Sites of feline coronavirus persistence in healthy cats. J Gen Virol 2010, 91, 1698–1707, doi: 10.1099/vir.0.020214-0.
Open DOI Search in Google Scholar Back to article
Lewis C.S., Porte E., Matthews D., Kipar A., Tasker S., Helps C.R., Siddell S.G.: Genotyping coronaviruses associated with feline infectious peritonitis. J Gen Virol 2015, 96, 1358–1368, doi: 10.1099/vir.0.000084.
Open DOI Search in Google Scholar Back to article
Meli M., Kipar A., Müller C., Jenal K., Gönczi E., Borel N., Gunn-Moore D., Chalmers S., Lin F., Reinacher M., Lutz H.: High viral loads despite absence of clinical and pathological findings in cats experimentally infected with feline coronavirus type I and in naturally infected cats. J Feline Med Surg 2004, 6, 69–81, doi: 10.1016/j.jfms.2003.08.007.
Open DOI Search in Google Scholar Back to article
Montali R.J., Strandberg J.D.: Extraperitoneal lesions in feline infectious peritonitis. Vet Pathol 1972, 9, 109–121, doi: 10.1177/030098587200900204.
Open DOI Search in Google Scholar Back to article
Müller T.R., Penninck D., Webster C.R.L., Conrado F.O.: Abdominal ultrasonographic findings of cats with feline infectious peritonitis: an update. J Feline Med Surg 2023, 25, 1–10, doi: 10.1177/1098612X231216000.
Open DOI Search in Google Scholar Back to article
Pedersen N.C.: An update on feline infectious peritonitis: diagnostics and therapeutics. Vet J 2014, 201, 133–141, doi: 10.1016/j.tvjl.2014.04.017.
Open DOI Search in Google Scholar Back to article
Pedersen N.C., Allen C.E., Lyons L.A.: Pathogenesis of feline enteric coronavirus infection. J Feline Med Surg 2008, 10, 529–541, doi: 10.1016/j.jfms.2008.02.006.
Open DOI Search in Google Scholar Back to article
Spaulding K.A.: Sonographic evaluation of peritoneal effusion in small animals. Vet Radiol Ultrasound 1993, 34, 427–431, doi: 10.1111/j.1740-8261.1993.tb02031.x.
Open DOI Search in Google Scholar Back to article
Szulc D., Dokuzeylül B., Or M.E., Ayaş G., Dębiak P., Kalinowski M., Gronowska M., Adaszek Ł.: Ultrasound image of the internal organs of cats with the effusive form of feline infectious peritonitis. Med Weter 2025, 81, 605–611, doi: 10.21521/mw.7068.
Open DOI Search in Google Scholar Back to article
Takano T., Hohdatsu T., Toda A., Tanabe M., Koyama H.: TNF-alpha produced by feline infectious peritonitis virus-induced macrophages upregulates expression of feline aminopeptidase N. Virology 2007, 364, 64–72, doi: 10.1016/j.virol.2007.02.006.
Open DOI Search in Google Scholar Back to article
Tasker S., Addie D.D., Egberink H., Hofmann-Lehmann R., Hosie M.J., Truyen U., Belák S., Boucraut-Baralon C., Frymus T., Lloret A., Marsilio F., Pennisi M.G., Thiry E., Möstl K., Hartmann K.: Feline infectious peritonitis: European Advisory Board on Cat Diseases guidelines. Viruses 2023, 15, 1847, doi: 10.3390/v15091847.
Open DOI Search in Google Scholar Back to article
Taylor S.S., Coggins S., Barker E.N., Gunn-Moore D., Jeevaratnam K., Norris J.M., Tasker S.: Retrospective study and outcome of 307 cats with feline infectious peritonitis treated with remdesivir and GS-441524. J Feline Med Surg 2023, 25, 1098612X231194460, doi: 10.1177/1098612X231194460.
Open DOI Search in Google Scholar Back to article
Tsai H.Y., Chueh L.L., Lin C.N., Su B.L.: Clinicopathological findings and disease staging of feline infectious peritonitis: 51 cases from 2003 to 2009 in Taiwan. J Feline Med Surg 2011, 13, 74–80, doi: 10.1016/j.jfms.2010.09.014.
Open DOI Search in Google Scholar Back to article
Wolfe L.G., Griesemer R.A.: Feline infectious peritonitis. Pathol Vet 1966, 3, 255–270, doi: 10.1177/030098586600300309.
Open DOI Search in Google Scholar Back to article

Articles in this issue

DOI: https://doi.org/10.2478/jvetres-2026-0039 | Journal eISSN: 2450-8608 (formerly 2300-3235)

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Language: English

Submitted on: Jan 23, 2026

Accepted on: Jul 28, 2026

Published on: Aug 3, 2026

Published by: National Veterinary Research Institute in Pulawy

In partnership with: Paradigm Publishing Services

Keywords:

feline infectious peritonitis,

pericardial effusion,

Related subjects:

Microbiology and virology,

Life sciences, other,

Medicine,

Veterinary medicine

© 2026 Łukasz Mazurek, Stanisław Winiarczyk, Łukasz Adaszek, Katarzyna Michalak, Dorota Pietras-Ożga, published by National Veterinary Research Institute in Pulawy
This work is licensed under the Creative Commons Attribution 4.0 License.

AHEAD OF PRINT