Perfect diagnostic agreement between canine- and feline-specific parvovirus PoC antigen kits in feline panleukopenia.

Abstract

Timely diagnosis is essential for managing feline panleukopenia (FPL), a devastating disease of cats caused by feline parvovirus (FPV) or canine parvovirus variants (CPV-2a, -2b, -2c). To support swift clinical decisions, point-of-care (PoC) antigen kits offer frontline tools. Given their cost and availability advantages, CPV-specific kits are often used off-label in cats; however, their interchangeability with manufacturer-matched FPV-specific kits remains unverified. This study assessed the diagnostic agreement between paired canine- and feline-specific PoC parvovirus antigen tests from two manufacturers. Fifty cats (30 with acute gastroenteritis, 20 healthy) were tested using all test formats. All cats underwent PCR and sequencing for parvovirus typing. Tests from the same manufacturer showed near-perfect or perfect agreement for result interpretation (Cohen's κ: 0.919 and 1.000). This strong inter-kit concordance also extended to test line intensity (κ = 0.908 and 1.000). Antigen-positive results were limited to diseased cats, mirroring the distribution of PCR positives. The latter included all the 30 cases, and were typed by sequencing as follows: 28 FPV, 1 CPV-2a, and 1 CPV-2c. All kit types detected FPV and CPV variants, and agreement within each manufacturer's paired kits was consistent across detected viral types. This preliminary evidence suggests that for two manufacturers, CPV antigen tests were non-inferior to their FPV counterparts, supporting flexible, cost-effective FPL diagnosis in cats, regardless of implicated parvovirus types.