Perfect Beagle diet? Ok, there may be no such thing. But you can get very close with the right mix of nutrients from the right sources.
Beagles, like all dogs, need proteins. They are broken down into amino acids then built back up again into the kinds of proteins their bodies use to make muscle and other tissues. Higher protein levels are better for your Beagle, as much as 40% of the total.
The source of that protein is best found in meat rather than meat byproducts. Those byproducts can consist of lips, tendons, and other animal parts. Chunks of real beef or chicken are best, even when in dried kibble form.
Dogs need carbohydrates, just as humans do, to supply the energy for all biochemical processes. Cell repair and reproduction, chemical reactions, and muscle movement – along with hundreds of other biological activities – can only occur when they have the power to do so. Carbs supply that power.
That's why virtually every commercial dog food you see will contain things like rice, wheat, or corn as the second major ingredient. Far from being indigestible plant material (some people advocate feeding dogs only meat on the mistaken premise that wild canines are exclusively carnivores), they are a terrific source of vital complex carbohydrates.
Beagles begin to process fats for energy far sooner than people. The average human has to see a sharp carbohydrate deficit before the body naturally turns to burning fat. With Beagles, that happens after only a few minutes of vigorous exercise.
Here again, the source of fat is important. Chicken fat, fish oils, and some plant sources (yes, plants have fat molecules, too) such as safflower or flax oil are good. Animal sources supply energy while the plant fats promote good skin health.
Fatty acids should be part of the mix, as well. Omega-3 and omega-6 compounds are chemically closely related to fats and help keep skin and nerves healthy. Among other beneficial effects, they aid in healing tissue damage.
Just as with people, fiber is an important part of good nutrition. Beet pulp is one good source. It helps keep digestion smooth, a particular problem with these high activity dogs. Some types of fiber provide only roughage, but that's a good thing. It helps minimize diarrhea.
Beagles love to eat! As a result, they can be prone to obesity if their human companions are lax or too easygoing with the food. Amounts will vary, of course, but on average a 25 lb adult Beagle should receive between 2-4 cups per day of dried kibble.
The number should be on the lower end for smaller, less active dogs and at the top of the range for larger Beagles that get lots of exercise. Younger dogs, naturally, will tend to be more active, but even idle Beagles can burn lots of calories.
Use the figures given as a rough guideline and adjust the amount based on how your dog is shaped. Overweight dogs look overweight. Fit dogs look more slender near the rear and don't have sagging bellies.