Like all dogs, Cocker Spaniels need to be fed a good quality, nutritious diet to suit their ages and the amount of daily exercise they are given. Over-feeding a Cocker would result in them putting on weight and this can lead to all sorts of health issues. It can affect their joints, bones and heart which is especially true if a dog is still growing and developing. Carrying too much weight puts a lot of extra strain on their hips and backs too. It can also lead to a dog developing some sort of heart disease. Working Cockers generally need to be fed a diet that’s higher in protein so it provides the extra energy they need to work.