Objective—To evaluate 2 county trap-neuter-return
(TNR) programs for feral cat population management
via mathematical modeling.
Design—Theoretical population model.
Animals—Feral cats assessed from 1992 to 2003 in
San Diego County, California (n = 14,452), and from
1998 to 2004 in Alachua County, Florida (11,822).
Procedure—Data were analyzed with a mathematical
Ricker model to describe population dynamics of the
feral cats and modifications to the dynamics that
occurred as a result of the TNR programs.
Results—In both counties, results of analyses did not
indicate a consistent reduction in per capita growth,
the population multiplier, or the proportion of female
cats that were pregnant.
Conclusions and Clinical Relevance—Success of
feral cat management programs that use TNR can be
monitored with an easily collected set of data and statistical
analyses facilitated by population modeling
techniques. Results may be used to suggest possible
future monitoring and modification of TNR programs,
which could result in greater success controlling and
reducing feral cat populations. ( J Am Vet Med Assoc