Data from: Detection of feline coronavirus RNA in cats with feline infectious peritonitis and their housemates
Data files
May 04, 2026 version files 16.93 KB
Abstract
Feline coronavirus (FCoV), the causative agent behind feline infectious peritonitis (FIP), is one of the biggest infectious threats to feline health. Despite this threat, the tissue distribution and viral RNA levels in cats infected with feline coronaviruses are poorly understood in the context of natural infection. Here, we used a two-step reverse-transcription quantitative PCR (RT-qPCR) to examine viral RNA levels from different sampling sites in both cats that have been clinically suspected of FIP and their feline housemates. We show that the distribution and amount of FCoV viral RNA does not differ between FCoV-infected cats with FIP and their feline housemates in blood, conjunctiva, or feces. Furthermore, in all FIP and non-FIP cases, viral RNA levels were higher in fecal samples than the blood. Taken together these results show that amount of viral RNA does not differ between FCoV-infected cats with FIP and their healthy housemates in several sample types. Our results indicate a need for closer examination of FCoV pathogenesis independent of viral dissemination, including an assessment of intrahost evolution of FCoVs and FCoVs’ interactions with the feline immune system.
Dataset DOI: 10.5061/dryad.83bk3jb51
Description of the data and file structure
Files and variables
File: 06.2025_-_FIP_and_Housemate_Clinical_Data_Final_-_for_Dryad_Upload.csv
Description:
Variables
- Home number ID: ID number given to each home to indicate housemates
- FIPID: Unique identifier for each cat
- Included/excluded and group: Whether cat met inclusion criteria, or was excluded from analysis after sampling. If excluded, reason is given.
- Diagnosis Category: Confirmed; Very Likely; Highly Suspicious; Suspicious. Categories based on the 2022 AAFP/EveryCat FIP diagnosis guidelines and the European Advisory Board on Cat Diseases FIP guidelines, as summarized here:
- Confirmed: clinically consistent, confirmed with positive immunostaining for FCoV antigen in effusion or sample of affected organ(s).
- Very likely: clinically consistent but FCoV antigen testing is negative or was not performed; must have identification of FCoV RNA by RT-PCR on effusion or affected organ(s).
- Highly Suspicious: clinically consistent but WITHOUT confirmed presence of FCoV RNA by RT-PCR or FcoV antigen by immunostaining on appropriate samples (either negative result or testing not performed). Cats that are otherwise only Suspicious but have positive PCR on whole blood will be included as Highly Suspicious, since PCR on whole blood is not 100% specific for FIP. Cats that are otherwise Highly Suspicious but have negative PCR on whole blood will be included as Highly Suspicious, since PCR on whole blood is not sensitive for FIP.
- Suspicious: clinically consistent but WITHOUT cytology or histopathology effusion or affected organs (if samples are unable to be collected). Cats with cytology results on fluid or FNAs that are *not *consistent with FIP will *not *be included. Cats that are otherwise suspicious and have negative PCR on effusion or body tissues will be included as suspicious due to the low sensitivity of this test.
- Treated at time of enrollment (Y/N) If so how long?: Whether cat was receiving treatment at the time of sampling; if so, was excluded.
- Date samples collected: Date (MM/DD/YYYY)
- Sex: FI (female intact); FS (female spayed); MI (male intact); MN (male neutered)
- DOB: Date of birth (MM/DD/YYYY)
- Breed: cat breed as reported by owner.
- Predominant clinical form: Major clinical findings for cats with clinical FIP
- FCoV Serology/IFA: Results from commercially available feline coronavirus IFA serology. Prior to March 2022, submitted to Cornell University Animal Health Diagnostic Center, Serology/Immunology section (Feline Coronavirus ELISA); March 2022 and after, submitted to Texas A&M Veterinary Medical Diagnostic Laboratory, Virology section (Feline Coronavirus IFA).
- FCoV PCR and sample type: Results from commercially available feline coronavirus qPCR test. Submitted to Real-time PCR Research and Diagnostics Core Facility, University of California Davis (Feline Corona Virus qPCR)
Note: The code "Unk" is used to represent unknown information or missing data.
Cats (n = 75) were enrolled at the University of Wisconsin-Madison Veterinary Teaching Hospital, University of Wisconsin Veterinary Care after evaluation of symptoms based on owner report and veterinary review. Each cat was assigned an FIP Identification (FIPID) number to track sample intake and household relations. Cats were diagnosed according to the 2022 AAFP/EveryCat FIP diagnosis guidelines and the European Advisory Board on Cat Diseases FIP guidelines. Definitive diagnosis of FIP based on immunohistochemistry was not required for inclusion, rather cats could be included based on clinical suspicion. If known, date of birth, age at time of diagnosis, sex, breed, diagnosis category (FIP confirmed or suspected), and predominant clinical form were recorded at time of enrollment. Medical records were reviewed by a board-certified small animal internal medicine specialist veterinarian (EL) to determine diagnosis. Cats were not included if an alternative diagnosis (such as toxoplasmosis, congestive heart failure, or septic pleuritis) was reached. Cats that had already begun treatment with antiviral agents before time of sampling were excluded from the analyses.
Blood, fecal and conjunctival swabs, and effusion (if present) from cases of probable FIP (n = 36) were taken and owners were asked if the cat had healthy feline housemates. Housemates (n = 39) were recruited at a later date, depending on the owners’ availabilities. Due to the nature of sampling from naturally-infected, client owned cats, we could not control for the time of FIP and housemate sampling. Housemate appointments were usually scheduled within a week of the initial FIP cat appointments. Nine unexposed, healthy cats from single-cat households were also recruited to assess specificity of our assay. Due to the nature of the study, infection histories of all cats used in this case study are unknown. All cats used in this study were enrolled with the owners’ consent and studies were performed under IACUC approval protocol #V006485.