Whenever I have an appointment with a large or giant breed puppy, I bring up the subject of large breed puppy foods. Puppies that are going to grow up to be big dogs are predisposed to developmental orthopedic diseases (DOD) like osteochondritis dissecans and hip and elbow dysplasia. (I use an adult weight of 55 pounds as my somewhat arbitrary division between medium and large dogs.) Nutrition, or to be precise, over-nutrition, is an important risk factor of DOD.
The physiological details can be a bit overwhelming, but I summarize the situation like this: Dogs are not supposed to be all that big (40 to 45 pounds is what tends to result when dogs mate without human intervention). Breeding for increased size forces them into an unnaturally rapid rate of growth, which pushes the ability of the skeletal system to mature normally over its limits. Developmental orthopedic diseases are the result.
The number one goal when it comes to feeding large breed puppies is to avoid overfeeding, particularly when it comes to calories. By restricting caloric intake slightly, we can slow the puppy’s rate of growth. They still get as big as they would otherwise; it just takes them a little longer to get there. Puppies fed in this way are also slim, which decreases the load that their maturing frames need to carry. Large breed puppy foods achieve these results by having a reduced fat content, and since fat is the most calorie-dense nutrient category in food, the diet is therefore somewhat restricted in calories.
In general, foods designed for large breed puppies have a fat content of between 8% and 12% on a dry matter basis while standard puppy foods often contain between 10% and 25% fat. Of course, the benefits of fat and calorie restriction can be completely undone if a dog eats too much of the food. Large breed puppies should almost invariably be fed several measured meals throughout the day rather than being allowed to eat free choice.
Getting too much calcium in the diet and eating foods with a high calcium to phosphorus ratio also increases the risk of DOD in these dogs. Therefore, large breed puppy foods typically contain less calcium than do “regular” puppy foods and the manufacturers keep the ratio of calcium and phosphorus within fairly narrow limits. Veterinary nutritionists don’t agree as to what the exact levels of these nutrients should be, but the following recommendations are fairly typical.
While feeding a large breed puppy food does not completely eliminate a dog’s risk for DOD (genetics plays a big part as well), offering the right amount of the right diet is very important.
Dr. Jennifer Coates