Feline immunodeficiency virus (FIV) infection in domestic pet cats in Australia and New Zealand: Guidelines for diagnosis, prevention and management

Abstract

Despite the passage of over 30 years since its discovery, the importance of feline immunodeficiency virus (FIV) on the health and longevity of infected domestic cats is hotly debated amongst feline experts. Notwithstanding the absence of good quality information, Australian and New Zealand (NZ) veterinarians should aim to minimise the exposure of cats to FIV. The most reliable way to achieve this goal is to recommend that all pet cats are kept exclusively indoors, or with secure outdoor access (e.g., cat enclosures, secure gardens), with FIV testing of any in‐contact cats. All animal holding facilities should aim to individually house adult cats to limit the spread of FIV infection in groups of animals that are stressed and do not have established social hierarchies. Point‐of‐care (PoC) FIV antibody tests are available in Australia and NZ that can distinguish FIV‐infected and uninfected FIV‐vaccinated cats (Witness™ and Anigen Rapid™). Although testing of whole blood, serum or plasma remains the gold standard for FIV diagnosis, PoC testing using saliva may offer a welfare‐friendly alternative in the future. PCR testing to detect FIV infection is not recommended as a screening procedure since a negative PCR result does not rule out FIV infection and is only recommended in specific scenarios. Australia and NZ are two of three countries where a dual subtype FIV vaccine (Fel‐O‐Vax® FIV) is available and offers a further avenue for disease prevention. Since FIV vaccination only has a reported field effectiveness of 56% in Australia, and possibly lower in NZ, FIV‐vaccinated cats should undergo annual FIV testing prior to annual FIV re‐vaccination using a suitable PoC kit to check infection has not occurred in the preceding year. With FIV‐infected cats, clinicians should strive to be even more thorough than usual at detecting early signs of disease. The most effective way to enhance the quality of life and life expectancy of FIV‐infected cats is to optimise basic husbandry and to treat any concurrent conditions early in the disease course. Currently, no available drugs are registered for the treatment of FIV infection. Critically, the euthanasia of healthy FIV‐infected cats, and sick FIV‐infected cats without appropriate clinical investigations, should not occur.

Field Performance of a Rapid Test to Detect Progressive, Regressive, and Abortive Feline Leukemia Virus Infections in Domestic Cats in Australia and Germany

“…It was also available in North America from 2003 to 2017, but has never been commercially available in Europe. Every jurisdiction should perform its own testing to determine the accuracy of any FIV PoC test kit, including v-RetroFel ® FIV, prior to adopting them for use [ 61 ].…”

“…The sensitivity and specificity of FIV RealPCR ® testing under Australian conditions were reported to be 92% and 99% [ 60 ]. Virus isolation was used to confirm FIV infection in the two FIV-vaccinated cats at the University of Florida and the University of Glasgow [ 60 , 61 ].…”

Clinicopathological and Epidemiological Findings in Pet Cats Naturally Infected with Feline Immunodeficiency Virus (FIV) in Australia

“…In some cases, residual EDTA blood was sent refrigerated for FIV molecular testing at a commercial laboratory (FIV RealPCR TM , IDEXX Laboratories, Brisbane, Queensland, Australia). FIV RealPCR TM testing detects proviral DNA (FIV DNA inserted into the cat’s genome), as well as viral RNA, due to a reverse-transcriptase (RT) step that is performed as part of the PCR assay [ 49 ]. FIV RealPCR TM is reported to have sensitivity and specificity of 92% and 99% in a population of FIV-vaccinated and FIV-unvaccinated cats in Australia [ 48 ].…”

2024 guidelines for the vaccination of dogs and cats – compiled by the Vaccination Guidelines Group (VGG) of the World Small Animal Veterinary Association (WSAVA)

“…This vaccine remains available in Japan, Australia and New Zealand. Although efficacy of this vaccine against experimental, heterologous FIV challenge has been shown, there has long been debate about whether it can effectively cross‐protect against the many different subtypes of FIV found in different geographical areas (Beczkowski et al., 2015; Coleman et al., 2014; Dunham et al., 2006; Hosie et al., 1995; Stickney et al., 2020; Westman et al., 2022; Yamamoto et al., 2007). Experimental studies have shown conflicting results, some showing strong protection afforded by this vaccine and others showing absence of protection.…”

“…Until recently, use of this FIV vaccine complicated diagnosis of FIV infection. Vaccination leads to the production of antibodies, presence of which is typically used to make a diagnosis of FIV infection (Westman et al., 2022). Fortunately, there are commercially available, in‐practice antibody detection test kits that can discriminate between FIV infected and uninfected cats, so long as testing is not done soon after vaccination (Westman et al., 2017).…”