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Dog food is probably one of the most controversial topics that any dog owner will encounter. Vets strongly agree that all cats are carnivores; however on the topic of dogs, they are often divided.

If you want to provide the best food for your dog, you need to provide it the most natural food that you can and the types that it evolved to eat.

In the following article I provide a case for why dogs are essentially carnivores and not omnivores. It is not conclusive or the gospel, however much of the scientific principles that it is based upon are quite compelling. This article is only written to enlighten or expand the argument on what food best suits your dog.

Firstly there is conclusive proof that the modern domestic dog is a direct descendant of the grey wolf (canis lupus). All wolves and primitive wild dogs of Africa are carnivores. They hunt in packs and capture small or large animal prey as the main source of their diet. It is also true that on occasion they eat berries, fruit and some parts of plants, however this is nowhere near the amount of carbohydrates found in most modern packaged dog foods.

It is said that scientists agree that dogs physiologically do not require any carbohydrates in their diet, as fat and protein gained from meat are sufficient to sustain normal blood glucose levels. (ref 1)

For the omnivore case, dogs carry on the following omnivore metabolic conversions: carotene to Vitamin A; Trypotphpah to Niacin, Cysteine to Taurine; Linoleic acid to Arachidonic acid.

However as dogs evolved from wolves only a maximum of 15,000 years ago, they share the teeth, digestive system and behaviours clearly representative of carnivores.

While you are aware that the modern dog is a scavenger and some breeds will eat almost anything, this is more likely to be due to conditioning from humans and their innate wish to please humans. If they are hungry and something is put in front of them that smells OK, then they will eat it in our artificial environment – but they are NOT OPTIMISED to eating anything but meat.

Urban myth has it that wolves eat the contents of their prey’s stomachs, but further research has found that this only occurs when the prey's stomachs are too small to tear apart or food has been in very short supply (ref 3)

If you wonder why dog food manufacturers provide so much carbohydrate in dog food, all you need to do is compare the price per kilo of rice, corn or any other bulk grain to that of any meat. This is why we recommend buying your dog meat at local markets, with as low fat content as possible.

DOG TEETH and Jaw shape

Classically herbivores have flat back teeth to grind plants down into a ‘slush’ before ingesting. Many omnivores, such as humans also have flat rear teeth. Dogs, as do all classic carnivores, have no flat grinding teeth. Dog’s teeth are all sharp and are used for grabbing and tearing meat and hide of animals, they are not suitable for grinding vegetables (which is required to assist access to the plant proteins). (ref 3)

Dogs do not chew side to side like cows, dogs jaws are only able to move up and down in a chopping movement. This is so that when they capture a live animal their heavy skull and rigid jaw maximise the chance of making a kill.

Amylase enzyme in DOGS

Another major case of dogs being carnivores is the location of the amylase enzyme in their body. Omnivores and herbivores both have salivary amylase, carnivores don’t. (ref 2) Amalyse is an enzyme used by plant eaters to initiate breaking down starchy carbohydrates before they reach the stomach. While carnivores produce amylase, they only do so in the small intestine, which means that carnivores (and dogs) body’s must work overtime to digest and use nutrients in carbohydrates.

This also causes a dog’s pancreas to work overtime to create much higher levels of amylase to deal with starch, cellulose and carbohydrates of plant matter.

Physiology of dog’s digestive system

Like other carnivores, dogs in the wild eat infrequent large meals (as opposed to grazing on plants often). Carnivores (and dogs) have relatively large stomaches (very elastic) and much higher acid concentrations as well as short intestines. The reason for this is that meat (fresh and buried) often have highly toxic bacteria in them. High acid and short intestines means that dogs can break down the meat proteins and fats fast, retrieve the nutrients and expel the waste and any bad bacteria that is left, quickly. Dogs even have the classic carnivore unsacculated colon, which means that it is smooth and designed to allow food (ie meat stripped of its nutrients) to pass through quickly. (ref 3)

Omnivore and herbivore digestive systems by contrast to dogs’, have small stomaches and intestines up to ten times their body length. This allows the much lower acid concentrations the time to extract nutrients from plant matter as it slowly ferments.

If a dog eat too much plant matter that requires grinding (which they can’t do), they are likely to suffer from gastric problems. Also it should be noted that dogs do not have the type of ‘friendly’ bacteria required to break down cellulose and starch meaning that most of the nutrients in plant matter are not available to them. (ref 3)

This obviously means that if you feed your dog anything in bulk beside meat, with the amalyse protein issue, bacteria issue, and short intestines they are unable to sufficiently process most of the plant and grain matter found in many manufactured dog foods. It also means that the acid that is meant to be working on the meat is now essentially diluted (as it tries to work on the non-meat components, making the breaking down of meat proteins more inefficient too).

NUTRIENTS AVAILABLE TO DOGS FROM MEAT

Not being a scientist, I was partially sceptical that meat could deliver all of the nutrients required for any animal. I was surprised to find the following information, which suggests that chicken and/or red meat has the nutrient potential to satisfy any carnivore, and dog.

Chicken Nutrients

The following information is available in more complete form from ref 4. The %DV is daily intake for a human, and not a dog.

Chicken has the following Good points “it is low in Sodium and a good source of Thiamin, Zinc, Copper and Manganese, and a very good source of Protein, Vitamin A, Vitamin C, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Iron, Phosphorus and Selenium.”

In fact the reference provides a detailed set of tables for all the various nutrient classes for 28 g of chicken. In summary their analysis shows that chicken typically contains 6.8g of protein (24%), 0.7% carbohydrates (no dietary fibre, no sugars ie lactose fructose etc), total fat was 1.8 g (0.6 saturated), had  18.7 g water and the following list of Proteins, Vitamins and Minerals.

For full nutrient analysis please view ref 4.

Ground Beef Nutrients: 70% lean meat / 30% fat

A dog’s diet should be varied for its own mental and physical needs. For this reason I looked at red meat nutrition analysis, and like the nutrition available from a standard chicken analysis, I was surprised by the completeness of this food. This is even for the beef 30% fat version that has some of the tables shown below. For the 30% fat beef the site says that: “The good: This food is low in Sodium. It is also a good source of Vitamin B12, Zinc and Selenium. The bad: This food is high in Saturated Fat and Cholesterol. This food also contains Trans Fat.”  This suggests that as for humans, it is much more preferable to feed your dog lean red meat.

For the 85g serving they analysed, the meat had 230 calories/  137 calories from fat. Cholesterol is 25%, total carbohydrates = 0% Protein = 22g = 26%.

NOTE – it should be remembered that the following nutrient tables are not included here: Calorie information; Carbohydrates (zero anyway); Fats and fatty acids, Sterols, Other (Water %, ash %). See ref 5 for full details.

SUGARS

People (as omnivores) need sugar in their blood to control glucose levels. Humans can use proteins to provide energy to their muscles, but their brain requires a certain level of glucose to function properly.   “Sugar or sweetener is an absolutely unnecessary ingredient in pet foods, added to make the product more attractive. Continuous intake can promote hypoglycemia, obesity, nervousness, cataracts, tooth decay, arthritis and allergies” ref 7.  Also it is useful to know that dogs do not possess sufficient lactase (the enzyme that breaks down lactose in milk) to enable them to digest it properly. This is why all milk products should be avoided as in the least it will cause them diarrhoea.  Another good reference for foods dogs should not eat can be found at Ref 6.

CONCLUSION

Just because your dog can be trained to eat non meat products, and may like the smell/ taste of man-made foods like pop corn, it does not mean that these foods are any good for them. Dogs were probably originally tamed by Chinese farmers and fed with food scraps that could have included a some grain and plant matter, but this would not have been the dog’s preference. Just because dogs have been conditioned to eat non meat foods, it does not mean that their physiology has evolved over the very short evolutionary time (of 5,000 to 15,00 years) to process non-meat foods. Like humans dogs can become addicted to sugar, but in the dogs case, sugars from fruits etc have a negative impact upon them.

Man has changed the domestic dog’s appearance vastly from their ancestors, however their internal systems and organs remain essentially unchanged. This is why you are likely to find plant materials fed to dogs remain essentially unchanged in their faeces. Surely this is one of the strongest clues that plant and grain foods provide little value to a dog. This is often why vegetables and grains are pre processed before being fed to a dog, but if this is required to trick their systems into digesting such foods, then isn’t this an unnatural act that provides little benefit?

While the domestic dog’s carnivore nature is essentially true, it is also true that man’s selective breeding of dogs for certain aesthetic reasons have created some breeds that have allergic reactions to certain types of foods, including some meats (or the fats accompanying them). If you feed your dog mainly meat, and it has allergies, it is a very good idea to consult a dog allergist to identify the exact cause (including potentially man made additives).

One caveat to the exclusive meat dog diet theory is that because of modern mans over-farming methods. It is possible that the grasses and grains used to feed most animals for domestic consumption have been depleted of essential vitamins and minerals. This is why when feeding your dog primarily a meat diet, it may be wise to supplement it with some dry food (vitamin enriched) product, or separate dog vitamin tablets.

As far as dog snacks are concerned, these should principally be meat derived products. They should have a high crude protein percentage and relatively low fat content (particularly as they grow older).

Dogs can survive on newly marketed meat and vegetable/ grain diets however based on the dog’s short evolution time it makes sense to feed your dog a variety of meals mainly or completely composed of meat.

Article by Bruce Dwyer. If you wish to use any of this information please refer to the article as a reference and provide a link to http://www.dogwalkersmelbourne.com.au

Reference

Ref 1   http://www.vetbalance.com/index.php?/carnivore-vs.-omnivore.html

Ref 2   http://www.dogfoodadvisor.com/canine-nutrition/dogs-carnivores-omnivores/

Ref 3  http://www.rawdogfood.com.au/carnivores.html

Ref 4  http://nutritiondata.self.com/facts/poultry-products/667/2

Ref 5  http://nutritiondata.self.com/facts/beef-products/8000/2

Ref 6   http://www.aspca.org/pet-care/poison-control/people-foods.aspx

Ref 7  http://www.dogfoodproject.com/index.php?page=badingredients