Epizootiology and Management of Feline Leukemia Virus in the Florida Puma

Abstract

Feline leukemia virus (FeLV) was not detected in Florida pumas (Puma concolor coryi) in almost 20 yr of surveillance; however, the finding of two FeLV antigen-positive pumas during the 2002–2003 capture season led to an investigation of FeLV in the population. Between January 1990 and April 2007, the proportion of pumas testing FeLV antibody positive increased, with antibody-positive pumas concentrated in the northern portion of puma range. Five of 131 (4%) pumas sampled between July 2000 and April 2007 were viremic, with all cases clustered in Okaloacoochee Slough (OKS). Clinical signs and clinical pathology at capture were absent or included lymphadenopathy, moderate-to-severe anemia, and lymphopenia. All viremic pumas died; causes of death were septicemia (n=2), intraspecific aggression (n=2), and anemia/dehydration (n=1). Outcome after FeLV exposure in pumas was similar to that in domestic cats, with evidence of regressive, latent, and persistent infections. Management of the epizootic included vaccination, and as of April 2007, 52 free-ranging pumas had received one or more inoculations. Vaccinations were concentrated in OKS and in a band between OKS and the remainder of the puma population. There have been no new cases since July 2004; however, the potential for reintroduction of the virus remains.

Genetic Characterization of Feline Leukemia Virus from Florida Panthers

“…(28)(29)(30)(31)(32). In contrast to FIV, which is found in many species of wild felids (33), FeLV in nondomestic felids has been reported only a few times, in captive cats, with documented or suspected exposure to infected domestic cats (5). Serologic survey of free-ranging populations found an absence of FeLV in pumas in California (34), among felids in Botswana (35), and among 38 free-ranging Florida panthers sampled during 1978-1991 (3).…”

“…An alignment of FeLV-Pco, FeLV-A, FeLV-B, and endogenous env nucleotide sequence (Figure 3 Figure 3) and on the basis of in vitro receptor utilization studies (5). The aligned sequences of the LTRs and the env region were analyzed as separate datasets.…”

“…However, since early 2001, 23 panthers (>33% of the population) were found to be positive for FeLV antibodies, and at least 5 adult panthers were positive for FeLV antigen and subsequently died. In the 3 panthers available for necropsy, evidence was found of diseases compatible with FeLV infection (5). We describe the molecular genetic characterization of circulating FeLV strains isolated from the 2001-2005 outbreak and compare them with FeLV strains isolated from domestic cats.…”

“…By the 1970s, Florida panther numbers diminished to ≈30 because of hunting and habitat destruction. Since the early 1980s, the population has been studied extensively by monitoring a large proportion of adults by radio telemetry (2)(3)(4)(5). In the early 1990s, concern over the fate of the population increased as signs of inbreeding and loss of genetic diversity were reported.…”

Variability in assays used for detection of lentiviral infection in bobcats (Lynx rufus), pumas (Puma concolor), and ocelots (Leopardus pardalis)

“…Although few studies have investigated the clinical consequences of lentiviral infection in wild felids, a recent study has demonstrated that infection in wild African lions (P. leo) and pumas causes CD4+ lymphocyte depression (Miller et al, 2006;Roelke et al, 2006). Further, feline leukemia virus (FeLV) infection in feral domestic cats (Felis catus) has been associated with FIV infection (Luria et al, 2004), and FeLV has recently been reported in the endangered Florida panther (Puma concolor coryi) population (Cunningham et al, 2004), posing an additional threat to the persistence of this subspecies. Finally, just as FeLV was likely transmitted from domestic cats to Florida panthers, domestic cat FIV spillover into populations of wild felids could have potentially devastating consequences.…”