Feeding your pet a vet-recommended diet

Sometimes a vet suggests a special food for a dog or cat.

It might be for the kidneys, the skin, digestion or the waistline. A little know-how helps you feed it well and get the most from it.

These notes draw on the rules for these foods in Great Britain, and on advice from UK Pet Food and the World Small Animal Veterinary Association.

What a veterinary diet is

The law calls these foods feed for particular nutritional purposes, or dietetic feed. They meet the needs of animals whose bodies are, or could be, working less well for a while or for good.

In Great Britain, a dietetic food can only be sold for a purpose that is on an official list. It must also have the nutritional features that the list sets for that purpose.

What the label tells you

The list covers dozens of purposes. For dogs and cats they include support for the kidneys, support for the skin, help with food intolerances, dissolving struvite stones and losing excess weight.

Each purpose comes with a recommended length of use. A food to support the kidneys is used initially for up to 6 months. Its label must say that advice from a vet is recommended before use and before using it for longer.

A food for intolerances is tried for 3 to 8 weeks. If the signs go away, it can then be used initially for up to a year.

Complete or complementary

A complete food has everything needed for a daily ration on its own. A complementary food only does that alongside other food.

Many dietetic foods must be sold as complete foods. The World Small Animal Veterinary Association says complementary foods should make up a small part of the diet, 10% or less, or be fed under a vet's supervision if they are a therapeutic diet.

Getting the amounts right

UK Pet Food suggests weighing your pet's food on accurate kitchen scales, rather than guessing by volume. The feeding guide on a pack is only a starting point.

Your vet can help you find your pet's ideal body condition. You can then adjust the amount as they gain or lose weight.

Treats and snacks should be no more than 10% of the day's calories. On a weight-loss food, the label will remind you not to go over the recommended daily energy intake.

Working with your vet

A few questions make the most of each visit.

What is the food for, and how will we know it is helping?
How long should my pet stay on it?
Can my pet have treats, and which ones?
When should we check in again?

The World Small Animal Veterinary Association notes that words like "holistic" or "premium" on a pack are not regulated. They tell you little about the food's nutrition.

For everyday food, UK Pet Food suggests looking for a food that is complete, balanced, digestible, tasty to your pet and safe. Wet or dry matters less than what is in it.