The most important aspect of the diet is it’s macronutrient content- how much protein, carbohydrates, fat, fiber is in the diet. THE MOST IMPORTANT aspect of the diet, overriding all other concerns. It must be species-appropriate too; obviously a diet for a horse (high fiber, low protein) would be inappropriate for a cat.
For dogs, fat is the most essential component of the diet. If the dog isn’t getting at least 35% of its calories from fat, the dog’s body doesn’t work properly; the more endurance the dog needs, the more of its calories should come from fat- active dogs should get at least 45 to 50% of their calories from fat. All dogs should get around 30 to 35% of their calories from protein as well. These numbers are well-established in good solid studies. You have to do some math- the real way to compare diets is to calculate the % calories from each component.
A typical raw diet would provide 30 to 40% of its calories from protein, and 50 to 60% from fat. These are healthy numbers for dogs.
A typical kibble with 25% protein/15% fat on the label would provide 24% of calories from protein and 35% from fat. These numbers are too low; dogs on these diets are running on carbohydrates, which are unhealthy for dogs.
A typical “performance” type kibble usually lists 30% protein/ 20% fat or thereabouts on the label. Oddly enough, when you calculate the % calories from each component, you get 27% of calories from protein, 45% from fat, which is close to what you want for a healthy dog- preferably you’d want a bit more protein and little more fat, which the better performance foods provide; for example, Diamond Naturals Extreme Athlete is 25% fat/32% protein, and Anamet Ultra is 32% protein/30% fat. Most of the performance foods are chicken and rice based (except proplan, which is corn gluten based). The person above who was claiming that dogs do really well on Performance kibbles is correct- these are fine foods, and have been around for decades.
If you take a trendy “grain free” food like TOTW, you notice it has 32% protein/ 18% fat. That’s pretty close to 20% you say; but fat is energy dense and even minor variations can cause big changes in % calories. If you calculate % calories from fat and protein for TOTW, you get 30% from protein, 41% from fat. Acceptable, but the fat is starting to drop out of the acceptable range. Go even lower- some of the grain-frees have 16% or even lower fat on the label- and they are not good for a dog, even though they are grain-free and have relatively high protein. Fat is important for dogs.
If you go the other direction, to one of the higher protein kibbles such as Nature’s variety instinct, with 42% protein/18% fat on the label, you find this provides 38% of the calories from protein and 41% from fat, which is a little low in fat. Fat is the most imporant concern- having more protein at the expense of fat is not good.
so if you’re looking at bags of dry kibble, the only way to get enough protein for a dog is to select a food that has at least 30% protein listed, preferably higher. If you’re planning to supplement a bit with fresh foods or canned foods, you can go down as low as 27%. As to fat, look for 18% as a bare minimum, preferably 20 or 22% instead. Being grain-free isn’t all that important; it’s far more important that the food have sufficient protein and especially fat.
Looking at the ingredient list tells you how good the protein is- not all protein is created equal. Plant-based proteins are of poor quality compared to animal-based proteins, so foods that get protein from corn gluten, soy, peas, or corn should be avoided. And odd unnamed products like “meat by-products” are essentally garbage from a slaughterhouse and are best avoided.
A nice simple chicken and rice formula with 32% protein/ 20% fat listed on the label is an ideal, digestible, and affordable diet for the vast majority of dogs.
