Based on the digestive system build-up and the dog's ability to synthesize the fatty acid arachidonic acid and the amino acid taurine, as well as utilize vegetable beta-carotene as vitamin A, dogs are classified as omnivores, not carnivores. It is also determined that dogs are genetically set up to digest carbohydrates like starch and glucose, unlike wolves.
From which sources can I find protein, fat and carbohydrate in my dog's food?
Most ingredients contain protein, fat and carbohydrate at the same time, but in different ratios. We often call them by their dominating energy source; protein source if they contain mostly protein, fat source if they contain mostly fat, etc. Below we have mentioned the most commonly used sources.
Protein sources can be any kind of meat, eggs, lenses, beans, etc. whereas animal sources are often the most bioavailable. Ingredients that provide all the 10 amino acids the dog needs are called complete protein sources. Krill meal is an example of such a protein source.
Fat sources can be animal adipose tissue, dairy fat (butter) or vegetable oils. The life essential omega-3 comes from both vegetable and marine sources, while omega-6 is mainly found in vegetable sources.
Looking more closely at omega-3, sources like krill and fish contributes with EPA and DHA, which the dog can utilize much better than the vegetable alpha-linolenic acid. The latter fatty acid must be converted by the body to EPA and DHA, and this process is not very effective in dogs. Only some EPA and almost no DHA are made from alpha-linolenic fatty acids.
Furthermore, much of the EPA and DHA from krill is bound in a phospholipid rather than in a triglyceride form. This might sound a bit complicated, but bottom line is omega-3 in phospholipid form is more rapidly integrated into the dog's cell membranes while triglycerides must be converted to phospholipid-omega-3 before it can integrate in cells. This makes krill meal an effective and potent omega-3 supplier in dog food.
Read our first article of the series here: Basic nutrition of our best friend, the dog: water and energy sources
Carb sources are mainly cereals (wheat, barley, oat), rice, potato or corn, but can also be vegetables, beans and pulses. As you may have noticed we haven't mentioned any animal sources, since they are very limited in carbohydrates (only small amounts of glucose may be present). The vegetable sources usually require some form of heat treatment in order for the energy in them to be accessible.
Now, you know the basics around your best friend’s digestive system, different energy sources, body building blocks and the healthy fatty acid omega-3.
Next chapter will be about important micronutrients: the vitamins and minerals. We will also look into hydration of the active dog.