Peer-reviewed veterinary case report
Whole blood testing finds more cats with low-level feline leukemia
By Beall, Melissa J et al.·Published in Journal of feline medicine and surgery·2025·IDEXX Laboratories, United States·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Feline leukemia virus lifetime study: whole blood samples increase detection of low positive cats with extended long-term survival.
- Species:
- cat
Plain-English summary
A study followed a group of cats diagnosed with feline leukemia virus (FeLV) to see how different blood tests could help identify those with lower levels of the virus and predict their long-term survival. Researchers found that using whole blood samples was more effective at detecting low positive FeLV cases compared to plasma or serum. After monitoring these cats for up to eight years, they discovered that about 66% of the low positive cats were still alive, while only a small percentage of high positive cats survived. This suggests that with the right testing, many cats with lower levels of FeLV can live longer, healthier lives.
People also search for: cat leukemia virus symptoms · feline leukemia treatment options · how long can a cat live with FeLV
Abstract
ObjectivesThousands of cats in the USA are newly diagnosed with feline leukemia virus (FeLV) each year, and known FeLV-infected cats are increasingly adopted from shelters. This study investigated optimal sample types to identify FeLV-infected cats and predictors of long-term survival in a cohort of FeLV-positive cats followed for up to 8 years after diagnosis.MethodsPreviously, 127 FeLV p27 antigen-positive cats were enrolled in a prospective study. Whole blood, plasma and serum were collected at enrollment and monthly for 6 months. All sample types were tested on SNAP FIV/FeLV Combo Test (SNAP) monthly, and results from microtiter plate ELISA (PetChek) for p27 antigen and a quantitative RT-PCR (qPCR) for proviral DNA were used for confirmation and classification of infection status (high positive, low positive or cryptic/negative). After the 6-month testing phase, cats entered a lifetime survival monitoring phase. Owner-reported status in the current study extended previous survival results by 4 years.ResultsTesting anticoagulated whole blood on SNAP at enrollment identified five and nine more FeLV-infected low positive cats (n = 29) than plasma or serum, respectively. Although some low positive (n = 11) cats demonstrated variable test results on SNAP with plasma and serum, others (n = 17) were SNAP positive with all three sample types and classified as low positive based on PetChek and qPCR results. After an additional 4 years of monitoring, low positive cats had not reached a median survival, with 19/29 (66%) cats still alive compared with 2/90 (2.2%) high positive cats.Conclusions and relevanceAnticoagulated whole blood on SNAP was a sensitive indicator of FeLV infection relative to plasma and serum and therefore should be the preferred diagnostic sample for FeLV antigen testing. Combining the results of whole blood antigen testing, PetChek and qPCR identified cats as high positive, low positive or cryptic/negative, with high positive cats having higher risk for early mortality. Use of these diagnostic tools facilitates the management of FeLV as a chronic condition.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41215536/