Lew Olson's newly revised edition is filled with an abundance of new topics and information. Whether you are new to home feeding or a seasoned raw feeder, have a senior dog or a new puppy, a pregnant mom or a toy breed, this book presents all the information you need to make the best nutritional decisions for your dog.

Vegetarian Diet

Vegetarian Diet for Dogs?

By Lew Olson • August 2003 Newsletter
While searching for information on the best diets for dogs, you will find many articles that have been written in the last few years on vegetarian or even vegan (no animal protein), diets for dogs. It is interesting to note that almost all of these diets appear to imitate the vegetarian diets recommended for people. These diets are often high in grains, suggest using lots of vegetables, and sing the praises of tofu (soy product).

While a vegetarian diet is something you may choose for yourself, making this same choice for your dog is quite a different matter.

Humans are omnivorous. We have a medium length digestive tract, enzymes in our saliva to predigest starches, and grinding teeth to break down plant matter in order to enhance digestibility. People’s jaws move sideways, for better grinding ability, as well as up and down, and their teeth are adapted to eat both plant and animal foods.
Dogs are carnivores. They have a short, simple digestive tract developed for easy digestion of fats and animal proteins. They have no enzymes in their saliva, their jaws are on a hinge allowing only the jaw to move up and down (not sideways) and the back of the throat has a large opening for swallowing big chunks of food. All the teeth are sharp and pointed, developed for tearing and crushing rather than grinding.
Anatomy of a Carnivore;www.b-naturals.com
Protein is essential to organ and skin integrity, and to growth. It provides the building blocks for these components that are essential for life. Proteins are comprised of different amino acids. Each of these amino acids is specialized and all of them work together to keep the body healthy. In humans, nine amino acids are needed for a complete diet. In dogs, at least ten are needed and quite possibly eleven. As carnivores, they require certain amino acids in different ratios and amounts than humans.
As proponents of vegetarian diets point out, combining certain vegetables and grains can provide most of the essential amino acids, but this is based on data for humans, not canines. Dogs require certain amino acids that are readily available in animal sources, but not plant sources. These are primarily taurine and l-carnitine.
The Importance of Animal-Based Protein in Iams Dog Foods;

“High-quality animal-source proteins contain all the essential amino acids dogs need. In contrast, plant-based proteins may contain only some essential amino acids. . . . Animal-based proteins help dogs achieve optimal health.”
Taurine and L-Carnitine
New studies in nutrition and the heart in canines have shown some interesting results. Taurine has been shown to be essential to cats, but the emphasis in dogs has been neglected. New studies show that certain breeds prone to dilated cardiomyopathy (DCM), such as Newfoundlands, are often found to have taurine deficiencies. Studies are also currently being performed on Doberman Pinschers in this area. Other breeds that are believed to be affected include Boxers, Cocker Spaniels, and Golden Retrievers. While scientists believed that dog foods high enough in sulfur and proteins would allow canines to produce taurine, they now believe this may not always be true:
Dietary Taurine Deficiency and Dilated Cardiomyopathy in Dogs;
Carnitine: A Review;

“Carnitine deficiency has been shown to cause dilated cardiomyopathy in a small population of dogs, and effects of carnitine deficiency on other tissue are being explored.
Dilated Cardiomyopathy: A Daunting Disease of the Heart;

“Taurine, an essential amino acid found in meat, is important in many bodily processes, including normal heart function. Some dogs with DCM have abnormally low amounts of taurine in their blood plasma. This seems to be especially prevalent in Cocker Spaniels, Golden Retrievers and breeds not typically considered at risk for DCM. Taurine deficiency also has been associated with DCM in dogs fed an exclusively vegetarian diet and in some
Dalmatians fed a prescription diet that has since added higher levels of taurine.”
And while most vegan or vegetarian sites recommend adding l-carnitine and taurine to a these diets, they are still not addressing another concern . . . the digestibility of plant protein vs. animal protein. Ounce for ounce (or pound for pound), animal sources contain much more protein than what is found in plants (grains, starches and vegetables). Far more plant material will need to be included in the diet to achieve the amounts of protein needed by the dog, especially considering that plant proteins are less bioavailable (digestible and usable) to the canine. Animal proteins are highly digestible for canines, while plant proteins are not.
In order for a diet high in grains and starches to try to reach the amount of protein needed for a dog, it will ultimately lead to a diet high in sugar. This brings up another matter. Dogs’ digestive tracts labor under high carbohydrate diets, which are not natural to the canine.
“Dogs experience digestive and metabolic limitations to high grain diets, which reflect their evolution on diets relatively low in soluble carbohydrates.” Optimal Nutrition for Athletic Performance, With Emphasis on Fat Adaptation in Dogs and Horses – Kronfeld 1994.
Carbohydrates are also fattening to dogs, which leads to another dilemma, in that a diet utilizing carbohydrates as a main staple will need far more food to obtain enough protein for organ and tissue health. This in turn will lead to gastric upsets, gas and very large stools with much odor.
Soy Protein
Although soy is a common component of human vegetarian diets, it is much more questionable to use for dogs. Soy is not a complete protein, and is a common allergen in dogs as well. Replacing protein from meat with protein from soy does not give a dog a complete diet.
Dog Health Survey;

From a survey of dogs on a vegetarian diet: “Since all the commercial vegetarian dog foods eaten by the dogs in the study contained soy, very few dogs had no soy products in their diets — only 39 (13%). However, these 39 dogs were in substantially better health than the others. Ninety percent of the dogs who ate no soy products (35 dogs) were in good to excellent health as compared to 74.3% of dogs who did eat soy products. Also, the incidence
of skin problems was much lower in the dogs that ate no soy — only two dogs (5.1%) had skin problems compared with 10.7% of the dogs who ate soy products.”
Plant sources are also a poor source of minerals. Probably the most important one to consider is calcium. Plants, including grains, are a poor source of calcium. They are high in phosphorus, potassium and magnesium, but are low in calcium and sodium. Furthermore, grains and many vegetables are high in phytates, which block the absorption of calcium, iron, zinc, iodine and magnesium. This fact was brought to the attention of the dog food companies in the early 80’s. Rather than reduce the amount of grains and starches in their commercial products, they opted instead to add more calcium, zinc, magnesium and iron.
A vegetarian diet, and especially a vegan diet, would need to add calcium, zinc, magnesium, iron and iodine to balance the diet. The problem with adding minerals is that giving too much, or in improper combinations, can be just as dangerous as getting too little from the diet, and they need to be supplemented in specific amounts in order to balance with each other (most specifically calcium and phosphorus, and zinc and copper). Of all the nutrients we may supplement with dogs, balancing these minerals is of utmost importance if a diet is low or devoid of them.
Lastly, I am going to address vitamin deficiencies, and these include Vitamin A, the B vitamins and Vitamin D.
This website describes very well the vitamin deficiencies that occur when feeding a vegetarian diet:
Nutritional Adequacy of Vegetarian Diets;
Vitamin A found in plant sources is beta carotene. Dogs (and especially cats) have difficulty converting beta carotene to Vitamin A. A diet for dogs must contain some animal proteins to provide this important vitamin.
Water Soluable Vitamins – Victamin C & Vitamin B Complex in Dogs;

“Niacin [vitamin B3] deficiency is generally encountered when owners formulate their own diets for their pets and do not include meat as part of the ration. Be very careful when trying to convert a pet into a vegetarian. . . .
Riboflavin [vitamin B2] is found naturally in organ meats and dairy products. It is lowest in grains, vegetables, and fruits. The unsupplemented vegetarian pet is at extreme risk of developing a riboflavin deficiency. Dogs fed a diet deficient in vitamin B2 will have poor growth, eye abnormalities, weakness in rear limbs, and eventually heart failure.”
Vitamin D has been found to be lowered in blood plasma from dogs fed a vegetarian diet, which would be of a grave concern for growing puppies.
It is extremely difficult to prepare a proper vegetarian diet for dogs, and I believe it is not possible to feed a vegan diet and supply all the nutrition that a dog needs. Most vets do not recommend feeding a vegetarian diet to dogs.
The Beef on Vegetarian Pets;

A recent study of dogs in Europe fed a vegetarian diet showed that protein intake was inadequate for over half the dogs, calcium requirements were not met in 62% of the dogs’ diets, phosphorus requirements were not met in roughly half the dogs, 73% had an insufficient intake of sodium, a high number of blood samples showed insufficient amounts of iron, copper, zinc and iodine, as well as vitamin D, and 56% of the dogs were not getting enough vitamin B12. Even the commercial vegetarian diets were found to not meet a dog’s nutritional needs.
Nutritional Adequacy of Vegetarian Diets;
Even sources that support feeding vegetarian diets to dogs stress the complexity of supplying all the necessary nutrients, and the dangers of leaving them out, and the better ones all recommend feeding eggs and dairy, even if meat is not fed. No one should attempt to feed a vegetarian diet to their dog without a thorough understanding of a dog’s nutritional requirements and how those requirements can be met, including which supplements (and in what amounts) should be given. And no dog should be fed a vegan diet, which is incapable of meeting their nutritional needs.
Contact Me
If you would like to ask me any questions about my products, I would love to hear from you. Please check your return address when you send me email from my web site and try to write me again if you have not heard back from me.
To email: lewolson@earthlink.net
To order call toll free: 1-866-368-2728
To fax an order: 1-763-477-9588
Email orders are also accepted
© Copyright 2003 Lew Olson, All Rights Reserved

Leave a Comment