Switching from Puppy to Adult Dog Food

Using age as a starting point to decide when your dog has reached maturity is a great starting point, however, there is no one age that suits all puppies. There can be a variety of factors impacting a dog's maturity and when they have reached their adult size.

The age of maturity is generally determined by the closure of growth plates. Growth plates are soft, cartilaginous areas in the long bones (like those in the legs) that contain rapidly dividing cells. This rapid cell division is responsible for increasing the length of the bones. Similarly, the puppy's muscles and internal organs are growing to match this bone length increase, which is also a result of rapid cell division. Rapidly dividing cells require large amounts of protein as their building blocks and energy (typically sourced from fat) to continue to divide. Some puppies can put on 1 or more kilograms per week from this normal growth. This means that a puppy diet needs to meet these energy and protein demands so as to not delay healthy growth.

Growth can also occur too quickly, which often leads to joint developmental diseases, like Elbow Dysplasia. Diets can also contain too much protein and fat, which could lead to weight gain, which further hinders joint development. In order to prevent this excessive growth or weight gain, the ingredients in puppy diets should be regulated carefully. Nutritionally balanced and complete diets have tightly controlled calcium and phosphorus levels to control bone growth and an appropriate protein and fat content to prevent excess weight gain. Some premium diets may also include the amino acid L-carnitine to promote lean muscle mass growth.

As puppies get older, their adult teeth come in, they will shed their fluffy puppy coat to a coarser adult coat, their brain will be maturing and their immune system will be rapidly developing to support a healthy adult dog. A good puppy diet will take these factors into consideration and provide nutritional support for these key developmental areas. It's also the development of these areas, along with the nutrient requirements for growth, that make a puppy specific diet so important.

Based on this information, we can determine that a puppy will need to transition onto an adult diet once their growth stops, particularly when their growth plates close. So when is this? The age at which growth plates close depends on the individual dog and the only way to be certain would be to take a series of x-rays, which just isn't feasible. So instead, we make an estimation based on when the growth plates are most likely to close.

The time when growth will most likely stop and growth plates will close depends on the individual dog's breed, size, gender and health. This is because even within a breed group, there can be variations in size between dogs, especially in males compared to females. Some dogs may also have health conditions that prolong or shorten growth, or may have health conditions that require a diet change, such as a food allergy or sensitive stomach. Similarly, predicting the age of maturity in mixed breed dogs may not be as simple and their probable adult weight not as predictable.