“Exurban Feral Cat Seroprevalence of Feline Leukemia and Feline Immunodeficiency Viruses and Adult Survival,” published in the Southeastern Naturalist, 2017. Abstract available online here.
Over the course of 11 months, researchers humanely trapped 101 individual free-roaming cats in Russellville, Arkansas, “an exurban city comprised of populous urban areas intermixed with relatively natural areas” . Ninety-three cats were examined for general health with their blood samples screened for common cat infections.
Researchers reported feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) prevalence rates of 12.7% and 16.7%, respectively. These rates are considerably higher than those typically reported in the literature (see below), and are likely a reflection of what the study author describes as a “hotspot” for these diseases as well as the cats’ presumably unsterilized status (few details on sterilization status were provided) .
Rates of FIV and FeLV were higher than expected, likely a reflection of “hotspots” resulting from colonies of unsterilized cats.
A study of unowned free-roaming cats admitted to trap-neuter-vaccinate-return (TNVR) programs in Raleigh, North Carolina (733 cats), and Gainesville, Florida (1,143 cats), by contrast, revealed overall infection rates of 3.5% for FIV and 4.3% for FeLV, “similar to infection rates reported for owned cats” . Likewise, a study of managed free-roaming cats in Key Largo, Florida, reported infection rates of 3.3% and 3.6%, respectively, among the 2,327 cats tested . These results correspond reasonably well with those from large-scale studies examining prevalence rates in U.S. and Canadian cat populations (owned and unowned) [5–7].
Body condition scores
Results showed that 58 of 93 cats evaluated (62.4%) were in “ideal body condition,” receiving a body condition score (BCS) of 5 (on a scale of 1–9). Another 22 (23.7%) were considered underweight and 13 (14.0%) were considered overweight. These findings are comparable to those reported by other researchers [8–10] who have also documented improved BCS values following sterilization [8,9].
Trap-nights dependent on population density
Over the course of the study, these researchers trapped cats at both “developed” (i.e., dense human population, industrial and commercial buildings, etc.) and natural areas, observing “greater trapping success” in Russellville’s developed areas. Whereas capturing each individual cat in the developed areas required an average of 16.7 trap-nights (one trap-night being the equivalent of one trap set over one night), each cat in the natural areas required an average 50 trap-nights . This is likely the result of relatively higher cat densities in areas of dense human population , and the cats’ reliance on food provided by residents [12,13].
See related Issue Brief: Cat health and welfare after TNR: Considerations and concerns
Normand, C.M.; Urbanek, R.E. Exurban Feral Cat Seroprevalence of Feline Leukemia and Feline Immunodeficiency Viruses and Adult Survival. Southeastern Naturalist 2017, 16, 1–18.
Normand, C.M. Feral cat virus infection prevalence, survival, population density, and multi-scale habitat use in an exurban landscape. M.S., Arkansas Tech University: Ann Arbor, 2014.
Lee, I.T.; Levy, J.K.; Gorman, S.P.; Crawford, P.C.; Slater, M.R. Prevalence of feline leukemia virus infection and serum antibodies against feline immunodeficiency virus in unowned free-roaming cats. Journal of the American Veterinary Medical Association 2002, 220, 620–622.
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Zito, S.; Walker, J.; Gates, M.C.; Dale, A. A Preliminary Description of Companion Cat, Managed Stray Cat, and Unmanaged Stray Cat Welfare in Auckland, New Zealand Using a 5-Component Assessment Scale. Frontiers in Veterinary Science 2019, 6, 40.
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