Feline leukaemia virus: vaccination and risk factors | Vets &Clinics

The reference place for veterinarians #WeAreVets

Feline leukaemia virus: vaccination and risk factors

Chronic infection with feline leukaemia virus (FeLV) can have fatal consequences in cats. Given its importance, here we provide an update of some recently published considerations that may prove interesting. 

Managing a veterinary practice

We have selected three publications:

  • What is the therapeutic role of feline leukaemia vaccination against this virus?
  • Can we compare the risk factors for FeLV with those for feline immunodeficiency virus (FIV)?
  • Does feline leukaemia bear any relation to feline chronic gingivostomatitis?

Feline leukaemia vaccine as a treatment for FeLV

1) A study published by Helfer-Hungerbuehler et al. (2015) investigated whether the FeLV vaccine can help cats eliminate a chronic infection. To this end, the authors vaccinated six cats that already had chronic feline leukaemia virus following experimental infection.

No statistically significant differences were observed with respect to RNA viral load, p27 antigen load, the titre of FeLV antibodies or the cats’ life expectancy. Although some cats could synthesise antibodies against the virus they offered no protective effect.

Finally, they concluded that therapeutic vaccination in clinically healthy cats persistently infected with feline leukaemia virus did not offer any benefit and, therefore, all cats should be tested for FeLV infection before vaccination.

Risk factors for feline immunodeficiency virus and feline leukaemia virus: Common points

2) A study published by Chhetri et al. (2015) compared the risk factors for seropositivity to feline immunodeficiency virus and feline leukaemia virus among cats. The study was conceived to address the inconsistencies in the literature regarding the risk factors these two viruses are reputed to share. The authors performed a retrospective analysis of 696 cats seropositive for feline immunodeficiency virus and 593 seropositive for feline leukaemia virus.

The study compared shared risk factors reported in the literature such as age, sex, outdoor exposure and neuter status. The odds of being positive for feline immunodeficiency virus were statistically higher in male adult cats, regardless of their neuter status, and those with outdoor exposure.  Clinical disease was the strongest predictor of feline leukaemia virus seropositivity.

Feline chronic gingivostomatitis and its relationship with feline leukaemia virus

3) A study carried out by Rolim et al. (2016) presented the clinical, pathological, immunohistochemical and molecular characterisation of 27 cats with feline chronic gingivostomatitis (FCGS). They collected samples from lesions, then performed histological and immunohistochemical analyses for feline calicivirus, feline leukaemia virus and feline immunodeficiency virus.

The main clinical findings were:

With regard to the presence of virus antigens in the samples, feline leukaemia virus antigens were found in up to 29.6% of cats. Antigens for feline immunodeficiency virus were identified in one cat and feline calicivirus in none.

Given these results, they concluded that the cases of FCGS did not appear to be associated with feline calicivirus, but rather with feline leukaemia virus.

Vets & Clinics

Reference space for veterinarians