Are Feral Cat Colonies Dangerous?

Feral cats are a big problem in the UK – Britain is believed to have over 1 million feral cats roaming the country. The subject of feral cat colonies can be a controversial one, with some believing that they are a severe menace to humans, pets and wildlife whilst others feeling that they do no harm if managed correctly and even feeling a form of affection towards colonies they care for. Their impact can also depend on their numbers, the environment they live in (and vulnerability of native wildlife) as well as the diseases which they may be carrying.

What is a Feral Cat?

Contrary to what many people believe, feral cats are not wild cats or even stray cats (also known as “alley cats”). The former are wild species and the latter are domestic cats that have been abandoned by their humans or have strayed from home and gotten lost. Feral cats are also descended from domestic cats but unlike strays, they are usually born in the wild and generally live without human contact, which means that they do not have the same “friendly”, tame attitude that stray cats have towards humans. In fact, many feral kittens born in the wild have a lot of trouble adapting to domestic life if they are adopted by a human family, although some do adapt very well and even some feral adults will adapt to life as a “house pet”. It depends very much on the individual temperament of the cat as to how wild they are.

What is a Feral Cat Colony?

Again contrary to popular belief, cats are not always loners. In fact, feral cats usually live together in large groups called “colonies”. The chances of survival are greatly increased with multiple cats living together and looking after the kittens. These colonies congregate in areas where there is a good, sheltered hiding place, such as abandoned buildings or heavily wooded areas, and where there is a food source, such as a rubbish dump. In Europe in particular, feral cat colonies often set up in high rise housing project tenements, usually inhabiting the basement and getting in and out via any suitable exits, such as cracks in the walls, drains and ventilation holes.

Feral cats usually only have a lifespan of about 2 years if they survive their kittenhood – however, in a managed colony, their lifespan can be extended up to 5 years.

Are Feral Cats a Risk to Humans?

Like all animals, feral cats can carry parasites and diseases which can be transmitted to humans, known as zoonosis. These included toxoplasmosis, giardiasis, rabies and campylobacter. However, these are usually transmitted through contact therefore as long as precautions are taken, it is not an immediate hazard.

Other complaints tend to deal not so much with the health risk as with the nuisance factor of feral cats, such as urine spraying to mark territory, the noise (especially at night) made by fighting cats and the damage to gardens caused by cats digging and leaving faeces.

Are Feral Cats a Risk to Pets?

Again, feral cats will carry diseases and parasites which can be transmitted to pets and since they share the same anatomy as your house cat, they can be a particular risk in introducing feline diseases, such as feline leukaemia or feline immunodeficiency virus (FIV). Feral cats are particularly prone to these two diseases due to the frequent fluid exchange from constant fighting and mating. In addition, feral cats can be infested with a large numner of fleas, as well as intestinal bacteria and worms. They also often carry ear mites, ring worm and upper respiratory tract infections (e.g. cat flu). Even if they don’t come into direct contact with your pet, they may still transmit disease and parasites through their waste products, particularly if they are using your garden as a toilet!

They can also be a risk to dogs since they are likely to stand their ground and fight, thus inflicting injuries which may become infected or transmit disease. Similarly, they may encounter, fight and harm any domestic pet cats which are allowed to roam, particularly at night.

Are Feral Cats a Risk to Wildlife?

Here the answer is an unequivocal ‘yes’. Especially with island ecologies, the effect of feral cats on the local wildlife can be severe. In the UK, this may well still be tolerable as cats are an established species and do not endanger many of the native wild species but in places such as New Zealand, Australia and even parts of North America, they are regarded as a serious threat to local, endangered species. Some also worry that feral cat colonies living close to urban areas may attract other larger, more dangerous predators such as coyotes, bears, wolves, wild cats and feral dogs.

How Can We Control Feral Cat Colonies?

Like the subject of feral cats itself, the best way to control colonies is under a lot of debate. Under British Law, feral cats are actually classed as “vermin” and belong to the person on whose land they inhabit.

Extermination: The first solution most people think of is to cull the populations through shooting, poisoning or trapping and killing however many are against this method. Aside from believing that the methods used to cull are inhumane (and in any case, deliberating putting poison down for feral cats is illegal as it may also poison other wildlife or pets), they cite the “vacuum effect” as a reason this solution doesn’t work – in other words, as feral cats are killed or removed from an area, new ones from surrounding areas will move in and breed or existing cats which escape the cull will re-establish the population.

Ultimately, they argue that the solution lies with humans taking the responsibility of sterilising their domestic pet cats as these are the source of almost all feral cat colonies to begin with. They believe that programmes which only kill the feral cats without addressing the human accountability issue will never solve the problem.

Trap-Neuter-Release: An alternative solution proposed is to use a “Trap-Neuter-Return” (TNR) programme which are humane and argued to be effective. The sterilised cats are returned to a managed colony where volunteers feed and keep watch over them. In addition, kittens and certain tamer individuals are also adopted as pets. However, such programmes have met with difficulties and resistance in certain countries (e.g. Australia) and there is also some doubt on the long-term effectiveness of a TNR programme. In fact, opponents believe that feral cats in managed colonies pose an even greater risk to local wildlife as they are not affected by food pressures (and therefore less likely to starve or fall prey to predators or disease) – and so more likely to exist in greater population densities.

Within the UK, even the animal welfare societies have divided views over the management of feral cats with some advocating TNR programmes and others putting down all ferals’ brought into them. Regardless of which methods you believe in, the key still lies with neutering pets and responsible pet ownership.