Unowned domestic cats (Felis catus, ‘strays’) are a major management and conservation issue in many parts of the world, including Australia. Although the number of stray cats is unknown, approximately 50% of cats entering Australian shelters are classified as ‘stray’. Many of these cats are euthanased because of illness or aggressive temperament. Depending on shelter circumstances some cats may euthanased because of limited resources. There is also a human cost, with regular or large-scale euthanasia linked to poor mental health. In addition to concerns about euthanasia and health, free-roaming stray (and pet) cats create serious problems including possible disease and parasite transmission to other cats, wildlife and people, predation of wildlife, sub-lethal effects on prey species (e.g. avoidance-through-fear). Free-roaming cats are also vulnerable to vehicle collisions, accidental poisoning, and human persecution. Cats also cause significant nuisance for cat owners and non-cat owners alike through urine spraying, caterwauling, and fighting with other cats. Management plans for stray cats need to consider these issues as well as the impact on individual strays and people performing euthanasia.
Desexing stray cats and releasing them back onto the streets (termed Trap-Neuter-Release, ‘TNR’) is a strategy developed by cat lovers to prevent breeding, nuisance behaviour and euthanasia. Since its establishment, TNR has been increasingly advocated as an effective, humane and ethical solution to problems caused by stray cats living alongside humans. However, in Australia, TNR has previously been rejected as an inappropriate management strategy for stray cats by the New South Wales Government and the AVA, because of tenuous evidence that the strategy achieves its fundamental objectives. Nonetheless, TNR programmes do operate and some NGOs and veterinarians are calling for trials and widespread implementation of TNR in Australian cities.
However, existing data indicate that TNR falls short of these objectives because: (i) it is only effective under particular conditions of high management intensity and funding, and in closed populations, (ii) it is slow to achieve reductions/extinction, (iii) a high proportion of reductions comes from adoption, which can be implemented without TNR, (iv) desexed cats are returned to the environment, which does little to mitigate the major problems associated with free-roaming cats, (v) the fate of cats released back onto streets is unknown, (vi) TNR programmes do not necessarily prevent euthanasia, and, (vii) the provision of care by TNR programmes encourages the dumping of pet cats.
TNR proponents agree that some evidence currently available for TNR is not robust and use this as justification for advocating trials of TNR in Australia. Proponents also argue that the problems caused by stray cats in urban areas are exaggerated and attributable to other factors (e.g. impact of cat predation on wildlife is negligible in comparison with land clearing). However, I argue that presenting TNR as a solution to cat overpopulation is too simplistic, and that trials of TNR could actually damage efforts to increase responsible pet ownership and compliance with legal mandates relating to cats. Humane management of stray cats can be achieved with well-funded and coordinated adoption-programmes and increased community education about responsible pet ownership. The veterinary profession can assist efforts to manage stray cats by promoting and practicing Early Age Desexing of pet cats, offering discounted desexing to owners and shelters, offering adoption of shelter cats in private practices, and by complying with AVA recommendations and State legislations that prohibit TNR in Australia.