Almost half the UK’s pets need some kind of veterinary care during their lifetime, the Pet Health Council says, with treatment ranging from skin problems to hip replacements. A dog swallows up an average of £301 a year in general vet costs, Churchill, the insurer, estimates. If special treatment, such as X-rays, is involved, that figure can easily rise to £1,396 a year.

Owners are also increasingly held liable for their animals’ behaviour, be it biting a postman or scratching a neighbour’s garden shed.

But don’t rush off to sign an insurance contract too quickly. Pet insurance is a complicated business. For a start, costs vary hugely. In London, a middle-aged boxer dog could cost you anything from £85 to £321 a year, says insuresupermarket.com, the price comparison website. Your dog’s breed, age and your location all come into play.

Unfortunately, cheap isn’t always best. The devil, as so often, is in the detail. Michael Powell, of Defaqto, the financial research group, says: “Watch out for one crucial difference. Pre-condition offers will cover treatment for a certain condition up to a set amount. But once your pet has been treated, this condition is no longer covered.” Lifetime cover, on the other hand, is usually renewed every year.

Cover for general vet bills is the most important characteristic of a policy. Homebase and Argos will pay up to £1,000 a year, E&L’s products range from £2,000 to £6,000, while Marks & Spencer pays up to £7,000. In addition, insurers will often limit the cash available for specific treatment or the length of treatment.

Insurers such as Churchill, Norwich Union and Petplan all limit their cover to 12 months, but More Than has a limit-free policy. Tesco has recently launched Insurance Extra, a plan that ensures veterinary treatment will continue after 12 months, provided that the final bill does not exceed £4,000. This is not exactly crucial for your cat’s cold, but these options could prove vital if your pet develops a long-term illness such as arthritis.

Choosing the right policy in the first place is even more important because switching providers is not as straightforward as it might seem. Potential new insurers will usually exclude from your cover any pre-existing conditions.

David Pickett, of Sainsbury’s Bank, says: “Pet owners should ensure that they have good quality cover from the very beginning. Unfortunately, they often realise their policy’s failings only when they come to claim.”

Mr Powell says: “When choosing cover, it is vital to look very carefully at what is available and work out what works best for your particular pet. Read through the policy wording and, if in doubt, talk to someone directly. There are no general recipes; pet insurance is very individual.”

If you like to take your cat on holiday, for instance, make sure that your policy covers travel abroad.

The Pet Health Council points out that most preventive measures, such as vaccinations, flea control and castration, are not covered by any policies. Such costs need to be squeezed into your pet budget, somewhere between the meat-in-gravy lunch and the refreshing aloe vera shampoo.

For more on insurance visit www.timesonline.co.uk/insure

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