Pan-European Study on the Prevalence of the Feline Leukaemia Virus Infection – Reported by the European Advisory Board on Cat Diseases (ABCD Europe)

Abstract

Feline leukaemia virus (FeLV) is a retrovirus associated with fatal disease in progressively infected cats. While testing/removal and vaccination led to a decreased prevalence of FeLV, recently, this decrease has reportedly stagnated in some countries. This study aimed to prospectively determine the prevalence of FeLV viraemia in cats taken to veterinary facilities in 32 European countries. FeLV viral RNA was semiquantitatively detected in saliva, using RT-qPCR as a measure of viraemia. Risk and protective factors were assessed using an online questionnaire to report geographic, demographic, husbandry, FeLV vaccination, and clinical data. The overall prevalence of FeLV viraemia in cats visiting a veterinary facility, of which 10.4% were shelter and rescue cats, was 2.3% (141/6005; 95% CI: 2.0%–2.8%) with the highest prevalences in Portugal, Hungary, and Italy/Malta (5.7%–8.8%). Using multivariate analysis, seven risk factors (Southern Europe, male intact, 1–6 years of age, indoor and outdoor or outdoor-only living, living in a group of ≥5 cats, illness), and three protective factors (Northern Europe, Western Europe, pedigree cats) were identified. Using classification and regression tree (CART) analysis, the origin of cats in Europe, pedigree, and access to outdoors were important predictors of FeLV status. FeLV-infected sick cats shed more viral RNA than FeLV-infected healthy cats, and they suffered more frequently from anaemia, anorexia, and gingivitis/stomatitis than uninfected sick cats. Most cats had never been FeLV-vaccinated; vaccination rates were indirectly associated with the gross domestic product (GDP) per capita. In conclusion, we identified countries where FeLV was undetectable, demonstrating that the infection can be eradicated and highlighting those regions where awareness and prevention should be increased.

Prevalence and Genomic Diversity of Feline Leukemia Virus in Privately Owned and Shelter Cats in Aburrá Valley, Colombia

“…Recent studies conducted in developed countries, which assessed more than 62,000 cat samples from the United States and Canada at veterinary clinics and shelters [23], reported a general prevalence rate of 3.1%, which may have increased up to 4.7% in animals with oral lesions and up to 8% in animals with respiratory diseases [23]. This prevalence rate is similar to that of Malaysia (1.2%) [25], New Zealand (1-2.6%) [26,27] and Europe, wherein the overall prevalence rate of FeLV in cats visiting a veterinary facility was 2.3% (141/6005; 95% CI: 2.0-2.8%), with the highest prevalence rates in Portugal, Hungary and Italy/Malta (5.7-8.8%) [28], indicating that the prevalence rate of FeLV infection in developed countries is extremely low compared with that which was found in the present study.…”

2020 AAFP Feline Retrovirus Testing and Management Guidelines

“…A prospective study in Europe that tested cats visiting a veterinary facility for FeLV RNA in saliva as a measure of antigenemia from September 2016 to March 2017 found an overall prevalence of 2.3%. 5 The highest prevalence was in Southern Europe (5.5%) and the lowest in Northern Europe (0.7%). These studies show that although guidelines for prevention of infection have been available for decades, there remains a need to improve ad herence to testing and vaccination recommendations.…”

“…Combined use of testing and vaccination programs is likely the reason for the decrease in FeLV prevalence in Europe and North America in the initial decades after the virus was discovered. 4,5,14,45,82,83 However, recent studies indicate that the prevalence of FeLV has plateaued in some countries, so increased efforts are necessary to further decrease the prevalence. 4,64,84 In one study, a history of vaccination against FeLV was associated with a reduced risk of FeLV infection in cats treated for abscesses and bite wounds.…”

Recommendations on vaccination for Latin American small animal practitioners: a report of the WSAVA Vaccination Guidelines Group

“…The prevalence of FeLV was much higher in Europe 30 to 40 years ago than it is today. It is thought that the combination of (1) diagnostic testing for FeLV (which has become considerably more convenient and accurate over those decades), (2) suitable management of cats found to be infected and (3) widespread vaccination against FeLV, have together led to the substantial decrease in FeLV prevalence in some countries (Studer et al 2019) [EB1]. The first step in regions of LATAM where FeLV has not been well studied would be to determine local FeLV prevalence.…”