What you should be looking for is a low-fat, high-fiber dog food that is also low in sodium. Low-fat, low-calorie dog foods are important for all the reasons we've already mentioned, but especially because obesity in older dogs is extremely common. Otherwise, most healthy older dogs do quite well on high-fat diets, as long as you control portions. Try hand feeding your dog to entice him to eat.
You can also add some water or other whole foods, such as eggs, yogurt or cottage cheese, to stimulate your older dog's appetite. Some dogs don't tolerate it well). Working with your vet can help you find the diet that's actually best for your dog or cat, not just the best-marketed diet. Excess sodium in the diet can contribute to kidney disease and high blood pressure, which may be present for long periods before clinical signs appear.
Breaking kibble can be difficult for older dogs, who are more likely to have loose or infected teeth. Adult or older large breed dogs, unlike large breed puppies (which need more carefully controlled calcium levels than smaller breeds), do not necessarily need special dietary considerations. In reality, it's not essential to choose small breed food for older dogs; what they need nutritionally isn't much different from what larger breeds need. It will also vary depending on the size and health of your dog: the nutrient profile of a healthy adult dog will be very different from the nutrient profile of an adult dog with kidney disease.
Talk to your vet for recommendations and consider eating fresh dog food, which is easier for the body to break down and extract nutrients than some processed kibble or uncooked diets. Unfortunately, many diets that are marketed to older people that advertise glucosamine, chondroitin, EPA and DHA do not contain effective amounts of these substances. There are many good quality commercial diets available today, and their varying nutrient content offers many options to optimize the health of every adult dog and cat. For the average adult and adult dog, reducing calories reduces the risk of obesity and many other diseases, such as cancer, kidney disease, osteoarthritis and immune-mediated diseases.
It's important to include treats and snacks in the conversation with your vet about the right food options for your mature or adult dog. A protein-rich food might help; the usual recommendation for older pets is more than 75 grams of protein per 1000 calories. However, before considering switching to a food formula for older dogs, it's important to first consult with your dog's vet for a thorough physical and metabolic evaluation. As with any dietary change, don't hesitate to ask your holistic vet for specific recommendations based on your dog's size, age, breed, health status and unique requirements.
Dogs are mature when they reach half of their expected life expectancy and are older when they are in the last 25% of their expected life expectancy.