Choosing the right dog food

Match the life stage first

Puppy food is denser in energy, protein, calcium and phosphorus because a growing skeleton needs it. Adult food is formulated to maintain rather than build. Senior diets typically reduce calories and adjust protein and phosphorus for ageing kidneys. Feeding puppy food to an adult dog is a common cause of avoidable weight gain.

Size matters for large breeds

Large-breed puppies need controlled calcium and a controlled growth rate. Growing too fast is a direct risk factor for hip and elbow problems later. A large-breed puppy formula is not marketing.

Reading the label

• Ingredients are listed by weight before cooking, so "chicken" ahead of "maize" tells you less than it appears
• A named protein ("chicken meal") is more informative than an unnamed one ("meat and animal derivatives")
• Check the feeding guide against your dog's actual weight, and adjust to body condition rather than following the bag exactly
• Look for a statement that the food is complete, not a complementary feed - complementary foods are not meant to be the whole diet

Changing food

Change over 7 days: a quarter new for two days, half for two days, three quarters for two days, then all new. An abrupt switch is the usual cause of the diarrhoea people then blame on the new food.

Weight

You should be able to feel the ribs easily under a thin layer of fat, and see a waist from above. Overweight dogs live shorter lives and develop joint disease earlier. Measure meals rather than filling the bowl.