Printer-friendly versionWhenever you acquire a new cat or kitten, the first rule is to stick to their previous diet for the first week or so while they are settling in. Any changes after that should be made gradually, adding increasing amounts of the new food in with their old diet. Suddenly introducing a different food will often cause vomiting or diarrhoea. The occasional tit-bit or treat is normally fine, although they can make some cats very fussy about eating normal food and some cats with very sensitive tummies may not be able to tolerate any change to their diet. Some cats are intolerant to lactose in milk while others are fine. Start with small amounts only to see how your cat reacts.

There is quite a range of diets on the market now.

These tend to be less expensive than tinned foods, are more hygienic in warm weather and the bigger biscuits are better for your cat's teeth. If left down all day they allow the cat to snack frequently, something which is more natural for them as in the wild cats survive on lots of little meals (e.g. mice, voles, birds) caught through the day.
The disadvantage is that they can increase the risk of cystitis developing, particularly in overweight, inactive male cats fed exclusively on dried food.
There is a choice of either the cheaper supermarket brands or the more expensive brands such as Hill's sold through vets and good quality pet shops. The latter tend to be better balanced and are safe to use if you want to keep your cat on dried food only. It is important to ensure there is a good supply of fresh water at all times.
Some cats prefer tinned to dried, and it does ensure that they are getting plenty of water. However the teeth do tend to suffer, leading to early dental disease.
Often the most popular option is to feed a mixture of tinned and dried. There are now a number of dried foods designed to help keep the teeth clean (such as Hill’s oral care) which can be very useful to prevent dental disease, as long as they make up at least half of the diet.
Special kitten diets have balanced levels of vitamins, minerals and protein to ensure healthy growth, and should be fed until around 9 months of age. Hill’s and Iams make very good dried versions, or you can use some tinned as well.
Neutered Cats:
After spaying or castration, it is very common for cats to put on weight, and they can become obese. Hill’s and Iams produce lower calorie ‘Light’ versions of their diets which help to prevent this.
Older cats:
After 8-10 years of age cats start to become less efficient at digesting their food and their food requirements change. Hill’s, Iams and Whiskas all make senior diets. These are more digestible, higher in essential vitamins and minerals and usually lower in protein than normal foods.