Walking helps, but so does more strenuous exercise like playing fetch or playing with other dogs.
Weight control is much more difficult in cats because rarely can you get a cat to exercise, especially as it gets older. Some cats love to chase laser lights or feather toys, so those might work.
It also can be difficult when there are multiple cats in one house. One cat may need to lose weight. Another cat may only need to maintain weight. And yet another cat may have trouble gaining weight. So just leaving one food out for all the cats is a bad idea, as the cat that needs to lose weight will be the one eating the most.
Restrict calories, but also find the right type of food. Some cats do better with a high-protein, low-carbohydrate food, while others do better with a high-fiber diet.
Again it is hard to figure out the calorie content of the different foods and unfortunately many are packed with calories so that just a half of a cup of food may be over a cat’s daily intake.
Some cats do better with an all-canned-food diet because canned food has a higher moisture content and the ratio of ingredients can mimic their natural diet. You have to experiment and consult a veterinarian for input. The vet could suggest a prescription pet food.
There is another complication in cat weight loss. If forced to lose weight too quickly, they can develop a serious illness called hepatic lipidosis, or fatty liver disease, in which the sudden drop in calories causes their bodies to mobilize fat too rapidly and it gets deposited in the liver tissue and can cause the liver to start failing. Weight loss in pets is hard. Be diligent, be patient and don’t give up, because ultimately your dog’s or cat’s health depends on it.