Your puppy is changing in so many ways. In fact, the most rapid growth will take place in these first months of his life. His immune system is developing. Bones are growing. Muscles are getting stronger. All of this requires a nutrient-dense diet, formulated to support a medium-breed puppy's rate of development. To make sure your puppy is getting optimal nutrition to protect and maintain health and well-being, here are some key points to keep in mind.
From the time your puppy is weaned until 4 months of age, you should feed your puppy two to three meals a day, with the daily amount based on the guidelines of the food label. After 4 months of age, he should be fed twice a day on a regular schedule. Always have fresh water available.
Research shows that puppies need up to twice as much energy as adult dogs. Dramatic growth at this stage means your puppy requires an energy-rich, nutrient-dense complete and balanced diet. Puppies also require more protein than adult dogs. High-quality animal-based protein will help your puppy create new body tissue.
Not all puppies have the same nutritional needs. Medium-breed puppies actually have slightly higher metabolism rates per pound than large-breed puppies. And your puppy will reach his mature adult weight at about 12 months, sooner than larger breeds that reach adulthood as late as 24 months. Your puppy needs protein, fat, calcium, and phosphorus to support growth and development of bones, muscles, and other tissues. So giving him a food that supports his medium size is the easiest way to help make sure he's getting the right balance of nutrients for his metabolism and growth rate.
Remember, puppies have small stomachs. Make sure his food is nutrient-dense so he'll get a complete and balanced diet even though his stomach can only handle what seems like a small volume of food.
Aside from energy and protein, there are other important nutrients and ingredients vital to your puppy's diet:
These are important building blocks of nutrition. Look for them when you choose dry or canned dog food and when you select treats.
A medium-breed puppy reaches adult weight by about 12 months. You can begin feeding an adult dog food at this time, such as IAMS™ ProActive Health™ Adult MiniChunks. Your dog might not welcome the change at first, but don't worry. You can help ease the transition by gradually introducing the adult food. Try mixing 25% of the new food with 75% of his puppy food, then gradually change the proportions over the next three days until he's eating 100% adult food.

As dogs age, changes occur in the way their bodies function, so it makes sense that what they eat also might need to change. The following list of health issues might be more common in aging pets.
Decreased Immune System Function
Throughout a dog’s life, a process called peroxidation occurs. Peroxidation is a normal process that the body uses to destroy cells that outlive their usefulness and to kill germs, parasites, etc. This process, however, also can destroy or damage healthy cells. As your dog ages, the damage caused by peroxidation accumulates, which, in turn, increases the risk of certain problems, such as infections.
Antioxidants are naturally occurring nutrients that help maintain overall health by neutralizing the peroxidation process of cellular molecules. Some antioxidants, such as vitamin E, beta-carotene, and lutein, are naturally occurring nutrients.
Recent research sponsored by The IAMS™ Company found that dogs fed a diet rich in antioxidants such as vitamin E, lutein, or beta-carotene had improved immune responses and vaccine recognition. This might be especially important in senior dog care; IAMS research has found that as dogs age, immune responses can decrease.
More Frequent Intestinal Problems
Older dogs might have higher numbers of unfavorable bacteria and lower numbers of beneficial bacteria in their intestines, which can result in clinical signs of gastrointestinal problems (e.g., diarrhea).
Feeding a diet containing fructooligosaccharides (FOS), a unique fiber source that helps nutritionally maintain healthy intestinal bacterial populations, promotes growth of beneficial bacteria. Beet pulp, a moderably fermentable fiber source, also helps maintain intestinal health by providing energy for the cells lining the intestine and promoting small, firm stools.
Different dogs show signs of aging at different times, and much of this variation is associated with size. Larger dogs generally appear 'old' sooner than smaller dogs. The table below lists the age at which various groups of dogs should be transitioned to senior foods, such as IAMS™ ProActive Health™ Senior Plus.
| Weight Range | Age to Begin Transition |
|---|---|
| More than 90 lbs | 5 years |
| 51 to 90 lbs | 6 years |
| 21 to 50 lbs | 7 years |
| Up to 20 lbs | 7 years |