Immunocontraception for cats

Benka, V. A., & Levy, J. K. (2015). Vaccines for feline contraception GonaCon GnRH–hemocyanin conjugate immunocontraceptive. Journal of feline medicine and surgery, 17(9), 758-765.

Vaccine: GonaCon™ is the trade name of a GnRH–hemocyanin conjugate immunocontraceptive vaccine formulation shown to prevent reproduction and inhibit production of sex hormones in numerous mammalian species for extended durations. GonaCon is currently registered with the US Environmental Protection Agency (EPA) for contraception of female white-tailed deer, and GonaCon™-Equine for female wild horses and burros. Multiple formulations of this GnRH-hemocyanin conjugate immunocontraceptive vaccine have been developed at the National Wildlife Research Center in the United States.
Evidence base: Three studies employing an early generation vaccine formulation indicated its potential for multi-year contraception of female cats (median duration of effect in excess of 39.7 months). The contraceptive effect for male cats was less predictable and of shorter duration (median duration of effect 14 months). Since these initial feline studies there have been formulation composition changes, and further investigation of the safety, efficacy and duration of this contraceptive vaccine for cats is warranted.
Future prospects: Individual country regulations will determine if GonaCon could be registered for unowned, free-roaming and/or pet cats.

Potential biological control of cats in Australia

Moodie, E. (1995). The potential for biological control of feral cats in Australia. New South Wales National Parks and Wildlife Service.


There is a need to clarify the impacts of feral cats on wildlife populations and thus set clear objectives for their control.

No method of biological control is available for immediate use. Fertility control using a contraceptive vaccine is the option with the most promise. This approach and two other broad strategies (a mortality approach usint lethal disease and environmental manipulation) are discussed in detail.

Although Feline Parvovirus has been used in attempts to control feral cats elsewhere, animal welfare concerns and probable immunity are likely to prevent its use in mainland Australia. No other feline diseases would cause rapid death in a relatively humane manner to a large enough proportion of a cat population to be useful for biological control.

The diseases and ecology (including population dynamics, reproduction and behaviour) of cats, and community attitudes to their control are discussed in depth. Relatively little information was available on feral cats. Most is derived from studies of domestic cats. Research currently underway is described. More information is needed on the ecology and epidemiology of diseases in feral cat populations in order to develop predictive models for specific biological control agents. Serological surveys for viral diseases in feral populations are given nights priority.

A fertility control approach using an immunocontraceptive vaccine probably has a reasonable chance of success in relation to public acceptability if the technical hurdles can be overcome. These include ensuring that the vaccine is cat specific, that it induces sterility without affecting social behaviour and that it's effects last long enough to be worthwhile. No effective chemical sterilants are available.

Results of research programs on immunocontraception of rabbits and foxes should indicate whether it is a feasible option for vertebrate pest control. Non-transmissible agents are more likely to be publicly acceptable because of concerns over the safety or other species and pet cats.

Attributes of successful pest control programs (for cats and other vertebrate pest species) are discussed. Refinement and combined use of conventional control methods will be essential for future cat control whether of not biological control is used.

Virus-vectored immunocontraception to control feral cats

Courchamp, F. & S.J. Cornell. 2000. Virus-vectored immunocontraception to control feral
cats on islands: a mathematical model. Journal of Applied Ecology, 37: 903-913.

1.  Feral cats Felis catus introduced onto oceanic islands pose a major ecological threat to endemic vertebrates, but their control is difficult. Immunocontraception has not been considered previously as a method for their control or eradication, and therefore we used a modelling approach to assess whether virus-vectored immunocontraception (VVIC) might be effective.

2.  We compared the relative efficiency of cat control/eradication using immunocontraception and three different disseminating techniques, i.e. baits, genetically modified viral vectors, or both. We accounted for several forms of dynamic compensation likely to arise in a population with artificially reduced fertility.

3.  We conclude that, under the assumptions of our model, immunocontraception can control or eradicate feral cats on oceanic islands. VVIC was found to be a more efficient dissemination technique than baits, but an integrated method involving viral-infected baits was the most likely to lead to eradication.

4.  We advocate field trials of this VVIC technique, when available, under island conditions where any risks to non-target fauna would be minimal.