I have studied both rural and urban foxes for more than 30 years and now operate an urban fox deterrence consultancy.

In answer to Susan Casey (Letters, July 30) the simple fact is fox attacks on cats are very rare but not totally unknown.

Foxes, being scavengers, will drag off the carcasses of cats killed on the roads and even dig up family pets buried in the garden but, fortunately, most of them are too intelligent to risk losing an eye in a fight with an adult moggy.

Where conflict occurs it is often instigated by the cat defending its territory or food (the Fox Project has plenty of photographic evidence of cats attacking foxes).

Fox cubs, being young, curious and playful, will often “stalk” crisp packets or feathers moving in the wind, and are equally likely to “stalk” a passing cat, albeit at a safe distance.

On the other hand, foxes and cats occasionally become firm friends. A few years ago, a fox (known as Colin) was regularly seen walking the streets around Plumstead Common in the company of a large white cat late at night.

Of greater concern is the hunting of both cats and foxes at night by yobs with lurcher dogs.

Three weeks ago, at around 1am, a cat was killed by two loose dogs in my road and a week later at around the same time, the same dogs almost caught our neighbourhood vixen.

Neighbours are still trying to find out who owns these killer dogs.

From a cat welfare point of view, the golden rule is cats should be kept in at night to protect them from yobs with dogs, to prevent them arguing with foxes and to keep them from being squashed under the wheels of cars.

John Bryant Humane Urban Wildlife Deterrence Tormount Road, SE18