Detection of feline coronavirus RNA in cats with feline infectious peritonitis and their housemates

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 n..., 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, ..., # Data from: Detection of feline coronavirus RNA in cats with feline infectious peritonitis and their housemates Dataset DOI: [10.5061/dryad.83bk3jb51](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:**Â ##### 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 aff..., ,