Nutrients that help support life are traditionally divided into the categories of water, minerals, vitamins, carbohydrates, protein and fat. The last three are ‘energy’ ingredients that fuel the body functions – energy that makes muscles contract, helps cells pump chemicals across the cell membranes, and synthesize innumerable essential molecules. Each of these nutrients is used in a different way. Carbohydrates serve as a source of glucose to power cell metabolism. Proteins are essential building blocks for muscle, skin, hair, blood proteins, enzymes, and many other body components. Dietary fat offers over twice as much energy as both carbohydrates and proteins and serves as a source of essential fatty acids.
Caloric requirements vary with body mass. A 4,500 kilogram elephant needs to eat 136 kilos of grass and grain to satisfy its daily needs. In contrast, a hummingbird must consume half its body weight in sugar-rich nectar every day to survive. Some dogs stay perpetually thin regardless of what they are fed. Some of these individuals are so active that they burn calories as fast as they consume them, while others just don’t have an interest in eating large quantities. In either case, a ‘performance food’ with concentrated nutrients may be suitable, or the dog can be fed more frequently during the day. In some cases, a different form of diet may entice a dog to eat adequate quantities more often.
In our Canadian dog population, excessive thinness is a rare problem, but obesity is rampant. Some owners blame it on a sluggish metabolism, sometimes caused by a deficiency of thyroid hormone, which creates a tendency toward weight gain. Hypothyroid dogs put on pounds even if they are fed a ‘normal’ amount of food for their body weight. Supplementation with thyroid hormone boosts their metabolic rate, reducing their tendency to obesity.
Another option is to change the type of diet being fed. Providing a canned or homemade food with a higher water content, or using water to plump up dried dog food can help some dogs lose weight. Being a dog owner is a challenge. Not only must you feed the right food, you must also determine exactly how much of that diet your dog should eat each day. The best way to accomplish this is to periodically weigh your dog and to regularly feel its ribs to assess his body condition. If your dog’s weight cannot be easily controlled, an evaluation by your veterinarian is recommended. Remember your dog can become Diabetic if it is overweight and if your dog is overweight, it will shorten its lifespan.