Getting the right food to your dog can be a confusing matter. When you go to the grocery store, the shelves are filled with a daunting variety of commercial foods, which you find arrayed in things resembling lunch food sacks, cans, or hefty 40 pound bags.

Most if not all of these foods claim to be high-quality and well-balanced for your dog. The backs of the bags talk of testing laboratories that made sure each food was suitable and tasty for dogs of all sizes and stages of life. Yet in reality, each food contains a different mix of ingredients from the others, a mix that largely depends on the price.

We didn’t always have dog food at the grocery store. Our grandparents and great-grandparents would have giggled to see those tidy bags of dog food on the shelves. For most of human history, and up until quite recently, dogs ate scraps — they ate our leftovers. Despite all the cautions you hear from various authorities, dogs appeared to do quite well on this catch-as-catch-can scrap diet. After all, like us, they’re omnivores, and designed to do well on a dizzying array of food finds.

Dog food as we know it today was invented around the time of that wonderful World War Two technological revolution in canned and packaged foods. The point wasn’t to provide the ideal diet, it was to provide the kind of convenience that would usher us all into a new way of living.

And in a way, commercial dog food has done just that. It just doesn’t get any simpler than opening up a can or scooping out a bowl of food and setting it before your dog. In fact, some dogs are so diffident about these kinds of foods, you can “free feed” them, setting out a bowl all day and letting them pick whenever they feel like it. Needless to say, you could never do that with a big ham or a raw, juicy steak!

Still, there’s no denying that the convenience of prepackaged dog foods means that they’re bound to hold their place in many families’ lives. There are three basic types of prepared dog food on the market — dry food, semi-moist food, and canned. Below is a brief rundown on each one.

Dry Foods

Dry foods are at the pinnacle of convenience and low cost. Even though they’re dry, they still contain about 10% water, which means that eventually they begin to degrade and lose some of their nutrients, although you can store them for about a month with little degradation.

The cheapest brands of generic dog food on your local shelves contain a lot of corn, which costs a lot less than meat. To make it more palatable to your dog, who isn’t ordinarily a corn eater, the food may contain things called “digests,” which are treated concentrates that can make the food taste like chicken, beef, or anything else that’s appetizing to dogs.

Mid-priced dog foods have less corn and more meat products. However, the meat products are not usually the type of meat that we imagine. Instead, they’re usually something known as “meat meal,” which consists of byproducts and even waste products that are considered unsuitable for humans but adequate for pet food.

Some of the very best premium dog foods consist of human-grade meat, which is what we all like to imagine we’re feeding our dogs. With some brands, the food may also be organic, in which case it will say so. Typically, you’ll need to special-order these types of dog foods from the Internet — you won’t usually find them at the pet store.

From a health perspective, dry food has one big advantage over moist and semi-moist food, which is that it helps to clean his teeth. On the other hand, if you think about it, you can see that dry kibble is pretty far from your dog’s evolutionary diet. Eventually, this can take its toll in terms of mysterious skin allergies, digestive upsets, glucose-related problems and general vet bills.

Semi-Moist Foods

Also known as soft-moist, about a quarter of semi-moist foods consist of water. Even fussy eaters will usually deign to eat semi-moist foods, which is probably why it’s so easy to imagine a pug princess leaning over the bowl. Semi-moist foods are designed to simulate chunks of steak or hamburger, and usually come in tidy little packets. They’re definitely more expensive than dry dog food.

It’s worth remembering that for some reason, semi-moist foods contain a lot of sugar. Feeding sugar on a regular basis to an animal naturally designed for a low-carb, high-protein diet is playing with fire. You would want to stay well away from semi-moist foods if your dog has already developed diabetes.

Canned Foods

Dog owners that really like to spoil their dogs tend to gravitate toward canned foods. Goodness knows that dogs usually appreciate canned food a lot more than the dry variety. Even canned food, though, comes in several varieties, some of them containing a surprising amount of corn and grains, and others sticking mainly to meat byproducts.

One of the drawbacks of the canned food diet is that it can leave your dog’s teeth pretty sticky, unless you have some way of cleaning them (two options are a daily bout with a toothbrush, or giving your dog some raw, sturdy bones — never cooked — to chew on).

Another consideration is that the canned food diet is tantalizingly close to the canine’s natural diet, and yet not quite there. Although canned food is more convenient, it really isn’t terribly more inconvenient or expensive to get educated on a bio-appropriate “BARF” or raw foods diet for your dog, consisting of high-quality meat, bones and vegetables. An owner willing to fork out the money for canned food is an owner who may be willing to take it one step further and examine which foods could truly provide an optimal level of health and longevity in his four-footed friend.