Diabetes, kidney disease, pancreatitis, dental problems, overweight … Our dogs are not spared from diseases associated with an unbalanced diet. Choosing the right food for your canine is not easy, among the wide range of industrial food products and alternative approaches. To better understand the nutritional needs of dogs, let’s go back to the story from the beginning!
From wolf to dog, the story of the first animal domestication
The domestic dog ( Canis familiaris ) is the descendant of the gray wolf ( Canis lupus ). The links between this wild species and humans have gradually been forged. Back in the days when we were hunter-gatherers, it was common for wolves to roam around people to retrieve prey killed or injured while hunting. This easy to obtain food was a real windfall for these animals who know how to be opportunistic.
The relationship between our two species took a new turn when we settled down to become breeders and farmers. Our food waste has become a precious resource for these wild canines. Gradually, the wolf got used to the presence of man and who forged closer links. According to researchers at Cambridge University, the wolf, now a dog, would be the first species to have been domesticated by humans around 14,000 years ago. The first close cohabitations date back to around 30,000 years.
By selecting representatives with particular characteristics and crosses, the great diversity of current breeds has emerged, which vary greatly from a morphological point of view.
Although most current dog breeds no longer look so much like their ancestor, the dog and the wolf remain interbreeding and generate viable offspring. They are thus not that different; the dog is considered a subspecies of wolves. Does this proximity between the two species mean that we should feed our dogs based on the diet of wolves?
Is the dog carnivorous or omnivorous?
To determine the best diet to offer our dogs, it is first necessary to determine whether the dog is a carnivore, like the domestic cat or an omnivore. That is to say; a species can eat a bit of everything like humans, rats, or pigs.
The wolf, the ancestor of the dog, is a true carnivore
In nature, the wolf consumes:
- mainly large herbivorous mammals, ungulates: wild boar, deer, roe deer, elk, etc.
- In addition, small mammals: rodents, hares, beavers, etc.
- Occasionally, birds, reptiles, fish, or even insects.
Analyzes of their droppings reveal various plants, such as grass, berries, nuts, or even corn kernels. Their contribution to nutritional intake is considered negligible, and this behavior appears to be especially encountered in young people. Wolves are considered true carnivores.
This could explain a behavior observed in current dogs, which sometimes tastes a fruit or other vegetable food, which is not observed in cats (apart from the consumption of grass for medicinal purposes).
Dogs have a small number of taste receptors that respond to fruity foods. These receptors are absent in the cat, a strict carnivore (see my article How to give your cat the best food on this subject ).
The macronutrient distribution of the wolf’s diet is as follows:
- 54% protein;
- 45% lipids;
- 1% carbohydrates.
Evolution has made the dog omnivorous.
To survive among humans and be satisfied with a diet based on the consumption of waste rejected by them, the dog’s body has gradually adapted. Natural selection has thus favored animals capable of digesting the starches present in cereals cultivated by man.
The appearance of agriculture, and therefore the increase in the consumption of cereals, coincides with the beginning of the dog’s domestication.
Comparing the genetic profiles of dogs and wolves makes it possible to see which genes have been altered during domestication. A team of Swedish researchers has carried out extensive work on the subject.
They highlighted differences, in particular at the level of three genes involved in the digestion of starch:
- the AMY2B gene makes it possible to manufacture an enzyme capable of breaking down starch (an amylase). The wolf has 35 copies, the dog 136. But the difference does not stop there: in the dog’s pancreas, the enzyme is 38 times more expressed than in that of the wolf. And its activity is almost 5 times higher in dogs than in wolves.
- The MGAM gene, which produces glucoamylase maltase. This enzyme is involved in the second stage of starch digestion; it transforms maltose into glucose. Its expression is 12 times higher in the pancreas of dogs than in wolves.
- The SGLT1 gene. After the transformation of starch into glucose, the last stage of assimilation occurs at the level of the wall of the small intestine. A co-transporter, SGLT1, absorb glucose. Evolution has altered its structure, making it more effective in dogs.
Compared to the wolf, the dog has reduced the proportion of protein in its diet and increased carbohydrates. Its food profile is broken down into 30% protein, 63% fat, and 7% carbohydrate. Most specialists thus consider the dog to be omnivorous.
A diet less demanding than the cat
The dog inherited from its ancestor the wolf an ability to adapt to times when food is scarce. Unlike feral cats, which capture small prey regularly throughout the year, wolf access to food is not constant. Two types of period alternate:
- good times when it feeds in huge quantities when the pack has managed to kill a large herbivore. An animal can then absorb up to 22% of its weight in animal tissue!
- Periods of famine when he eats almost nothing.
Certain metabolic adaptations allow the wolf, and its offspring, the dog, to withstand periods of famine. For example, protein degradation is slow to retain sufficient nitrogen even in the absence of food. They can also produce certain essential compounds like niacin, taurine, arginine, and arachidonic acid. This distinguishes the dog from the domestic cat, entirely dependent on its diet to meet these needs.
How to choose food for your dog?
The omnivorous profile of the dog offers more flexibility for its diet than for the carnivorous cat. It is possible to offer him the leftovers of meals since the dawn of time; this corresponds to his eating habits. But it is still necessary that its owner has a healthy diet!
Gluten grain intolerance in dogs
In addition, it is essential to understand that the dog suffers from the same problems as humans concerning cereals. Indeed, as I demonstrate in my book survey on gluten, wheat has undergone many genetic transformations in recent years that have made it much less digestible for humans. If this is true for us, it is all the more true for the dog.
This is why it is not uncommon for many dogs to have a food intolerance to cereals and especially gluten cereals. In most cases, these are sensitivities and not severe gluten intolerance (celiac disease), an autoimmune disease. However, two breeds of dogs can present this autoimmune disease according to specialists :
- The Irish setter
- The border terrier
There are generally obvious digestive symptoms when intolerance is present: diarrhea, abdominal pain, and weight loss. But if it is a sensitivity (this is the most common), we generally encounter:
- Redness and itching
- Ligament fragility
- Ear infections and ear problems
A dog can also be intolerant of soy, dairy, or corn, although this is rarer. It is nevertheless common with industrial kibbles because the latter do not generally meet the standards on allergens. So even a wheat-free product may contain gluten (contamination in the manufacturing plant).
The BARF diet (“Biologically Appropriate Raw Food,” which means “Raw and Physiologically Appropriate Food”) aims to provide the animal with a natural diet best suited to these needs, based on unprocessed raw foods.
It must contain:
- raw meat, ensuring its quality to avoid any bacterial contamination;
- fleshy bones. Bones are sources of calcium, phosphorus, and magnesium. The dog has post-carnivorous molars, which allow it to grind them to extract the bone marrow rich in lipids.
- Offal. The internal organs (heart, lungs, liver, spleen, and kidneys) are a delicacy particularly rich in nutrients.
- Oil. It is advisable to favor oils rich in omega 3, such as rapeseed oil. Fish oils, rich in EPA and DHA, are ideal.
- Mashed fruits and vegetables.
BARF food is a healthy solution for a dog, but it is not mandatory to give such a specific diet as we have just seen above. In particular, raw meat is not required in large quantities. If we want to follow the evolutionary notion of dog food, raw meat will rather represent a supplement, which we will give to the dogs during the preparation of our own meals (if they contain meat). The cooked meat that remains on the plate will be a second source of animal protein.
A BARF power supply cost can also be relatively high, and its implementation requires little time. It is therefore not suitable for everyone.
Which croquettes to choose?
Dry food is a convenient option for feeding your dog. However, it is crucial to choose them well because the quality varies greatly from one product to another.
- Protein content. It must be closer to 30%. Meat or fish should come first in the ingredient list. Some brands use wild fish from sustainable fishing (MSC label). When the list of ingredients indicates “ meat and animal by-products ” associated, this is not a guarantee of quality: nothing specifies the share of both.
- Fatty substances. Vegetable oils from soybean, sunflower, and corn are richer in omega-6 fatty acids than omega-3, which is not ideal for the animal’s health. Animal fats are richer in EPA and DHA, the levels of which vary depending on the type of farming (chickens raised in battery packs are less attractive than those that frolic outside). Fish oil has a very favorable omega 6 / omega 3 profile. On the other hand, you should know that the cooking process of the croquettes is always harmful to the quality of the fats which oxidize.
- Carbohydrates. Some croquettes are displayed as “grain-free.” This name may suggest that they are richer in animal products. This is not necessarily the case: cereal starches are replaced by starches from other plants (potatoes, sweet potatoes in particular). This is not a guarantee of quality; cereal-free kibbles containing little protein are still kibbled to be avoided.
As with our food, favoring certified organic kibbles is a way to ensure that the plants they contain have not been treated with synthetic pesticides, a source of environmental pollution and that the meat comes from raised animals, in conditions more respectful of their well-being and the environment.
There are many kinds of kibble for sale on the internet. Personally, the ones I use for my dogs are organic grain-free Yarrah croquettes. The plants are organic, and the fish comes from sustainable fishing.
- Clutton-Brock J. 1995. Origins of the dog: domestication and early history In Serpell J (eds). The Domestic Dog, Its Evolution, Behavior, and Interactions With People Cambridge University Press: Cambridge; 7–20.
- Bosch G et al. Dietary nutrient profiles of wild wolves: insights for optimal dog nutrition ?. Br J Nutr . 2015; 113 Suppl: S40-S54.
- Axelsson E et al. The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature. 2013; 495 (7441): 360-364.
- Hewson-Hughes AK et al. Geometric analysis of macronutrient selection in breeds of the domestic dog, Canis lupus familiaris. Behav Ecol. 2013; 24 (1): 293‐304.