The most common health threat for dogs is obesity. Commercial foods taste great, so the mature dog will usually clean his plate. Some owners take this as a sign that the dog needs more food and increase the portion.

Owners enjoy being able to feed their dogs human food. This usually takes the form of table scraps, which are usually the fatty parts of meats rather than leftover vegetables. In addition to feeding calorie-laden foods as snacks, few owners take into consideration that these calories are being added to the dog's regular intake. If the dog is receiving more calories than he's burning up each day, he will gain weight.

Life-cycle changes can affect a dog's metabolism rate. The high-energy, fat-burning puppy matures, and suddenly his caloric needs drop. Additionally, spaying or neutering can lessen the shepherd's nervous energy, by eliminating his need to search for a mate, and thus cause a drop in caloric needs. If the mature shepherd continues to be fed the same portion size he received as a puppy, the shepherd is going to gain weight.

It is much easier to keep your shepherd from becoming obese than to reduce his excess weight. Keep an eye on your shepherd as he ages, and check the fat coverage over his rib cage frequently. You should be able to find each rib underneath the coat by pressing lightly with your fingers. If you have to exert more pressure to find the ribs, he's probably overweight.

Before you begin a health and fitness program for your over-weight shepherd, consult your veterinarian. She will give you exercise and feeding guidelines so that your shepherd doesn't lose too much weight too quickly.