Excess weight decreases both the quality of life of pet dogs and reduces their life expectancy. Overweight dogs find exercise and play more difficult and suffer more in the heat. They are more likely to suffer from joint problems such as arthritis, diabetes (insulin resistance), respiratory problems and other major diseases. Overweight dogs are also at greater risk of complications during surgery requiring general anaesthesia. A lifelong feeding study found that correctly fed dogs lived an average of two years longer than those that were allowed to become overweight.