We live in a changeable world. This is especially true in the last decades. The development of industry, harnessing various fuels, scientific discoveries, technological advances — all of these have literally transformed our world. 

I can remember in the late ’60s when I was in graduate school at Washington State University, I lived in a smaller community outside of town and the only choice for a phone service was a 10-party line. There were no cell phones, computers, tablets — all of which are now prominent in our lives. 

Along with these changes are the contributions of chemistry. It was learned how to make incredible new substances that were put to use in various ways. Many of these were marvelous but I wish to point out that these were new chemicals and often cherished because of enhanced qualities compared to natural, similar, material. One example that comes to mind is how often wood was sealed and protected by linseed oil. Then there were the new sealers developed, much more protective, and that lasted a much longer time. There was no longer the need to keep re-oiling wood. You can see why this would be appreciated. 

The part of this development that was not really considered is what effect these new substances would have on our environment. Even today, if you inquire about something you are about to use as to its effects on your health, or on the health of the natural world, you will find there is no information available. 

Another example of this lack of foresight is the embracing of plastic. As we now know plastic contamination is a serious problem. It is killing off much of the life in the sea, and there are recent reports that even our rain now contains millions of microscopic particles. Could this have been anticipated? I don’t know. If I put myself in the planning room for plastic development I doubt the possibility of microplastic accumulating in our bodies would ever enter my mind.

Nonetheless, this is an issue we have to deal with. Not just plastic but the many chemicals that are now part of our natural environment and have become important factors in the quality of our lives. 

In my work as a veterinarian, I think that one of the most important ideas I finally understood is how important these environmental chemicals are in our health. I have come, now, to think that these chemicals accumulating in our bodies is one of the major factors in the development of chronic disease in our animal friends. 

To discuss this with you, I would like to go into why my advice is now to change the way we eat and how we feed our animal companions. To put it simply the suggestion I make is to emphasize a plant-based diet. 

This idea of feeding a plant-based diet to dogs and cats is often met with incredulity, even ridicule. It seems to be going contrary to nature. If you have the patience let’s go into this and I will explain why this makes sense to me.


What we have discussed above translates to the problem of these chemicals accumulating in our bodies and affecting our health. The difference in eating or feeding a plant-based diet vs. a primarily meat diet is then the issue of chemical dose. 

You cannot avoid exposure to these completely, however, you can reduce the amount coming in by how you eat and this is significant. Understanding how to reduce exposure is best explained by discussing what we call the “food chain” or in the scientific world “bioaccumulation.” 

It works like this. The chemicals spread about in our environment are in the air, water, and soil. They often waft away from factories, industrial plants, the burning of coal, etc. They also enter the water from the sewage water from cities, or from factories dumping into rivers. As these chemicals move around with the wind, water movement, transport (exhaust, tire shedding, etc.) they end up where the plants we use for food are growing. It is even legal practice in the US to use sewage sludge from city water treatment plants, this being the most toxic material in the world. It is used as a fertilizer on food crops, to spread it over the soil for the plants to take up.


So it goes like this (the food chain). I will use a very simple example of just one of the chemicals and putting the amount in terms of drops, rather than micrograms or milligrams, so this is easier to understand. Let us say the plant growing in the soil gathers one drop of the chemical as it grows. That is how much it contains. 

The steer that is feeding on the plants, eats the plant and takes that drop into his body. It ends up in the tissues and is stored there. Let us say that the steer eats 50 plants during the day. That, then, is an accumulation of 50 drops of the chemical. This goes on day by day.

By day 2, there are 100 drops in the tissues.

By day 3, there are 150 drops.

By day 30, there are 1,500 drops.

After 5 months, there are 7,500 drops.

For sake of this discussion let us say that the steer, when slaughtered has 10,000 drops stored in the tissues — the muscles and organs.

Your dog is now fed that meat, containing these drops. Let us say that the portion of meat fed each day contains 500 drops. Each day your  dog accumulates 500 drops. 

After a year, stored in his body will be 365 x 500 = 182,500 drops.


Do you now see why this is of concern? In today’s world, there is not just one toxic chemical. Granted not all end up in the environment but many do depending on their chemistry. In the US there are 100,000 chemicals approved for use in our homes, businesses, factories, farms, schools, parks, etc. If you like, you can assume that our government has made sure that these are safe, but unfortunately that is not the case. Reports estimate the percent of these chemicals evaluated for health effects is well below 10%. That means that over 90% of we have no idea what they will do to us. Dogs and cats? Forget it. There are no tests that evaluate how these things will affect them.

Water treatment plants for towns and cities are said to test the water before putting it back into the rivers and lakes. It might vary but what I have read is that they test for 10 chemicals only. Not particularly reassuring.

Even if the chemicals are tested for safety before use, how would that be done? Usually by giving them to an animal — monkey, mouse, rat. Would they have the same sensitivity or reaction to the chemical as a human? A dog? No one knows. 

Basically, we are working in an unknown area. 


A common strategy that people use  to deal with this is to emphasize the body’s elimination of toxic material. Herbs, vitamins, supplements of various sorts are given for the purpose. This is a smart idea but only partially adequate. 

You have to realize that these chemicals that have been created over the last decades are done for a particular purpose. As said above, they do something that other natural chemicals, already in existence, are not able to do. This is what makes them useful and unique. But understand this — when a new chemical is created IT HAS NEVER EXISTED ON THE EARTH BEFORE. Our bodies have never encountered these and do not have an established way to deal with it. By “established” I mean that over the centuries there is an adaptation to the substances encountered in the natural world. If something not good for us gets in, there are mechanisms for dealing with it. We don’t need to go into a lot of detail, just realize that this “getting rid of” involves some kind of processing of the toxic substance, some alteration of it so it can travel to the kidneys and be peed out. 

That there are so many new substances has overwhelmed our ability to deal with them. The best the body can do is store them somewhere — in the body tissues. The concern then is that this storage over time accumulates enough of the chemical that it has health effects, it achieves the level of a drug dose. 

In the example above I used one chemical. More accurately, tests of people and animals have shown more like 400 chemicals stored in our bodies. Tests of newborn babies finds, on average, babies are born with over 300 chemicals already in their tissues. Some of these chemicals are also known to interfere with the normal development of the child.

We have gotten ourselves into some deep doo-doo.


Granted you can think I am exaggerating or putting too much importance on this. I will mention, however, that this information has been published in many, many scientific reports. There are even fields of study in this. 

In my veterinary experience, one of the questions that is to be considered is why chronic disease in animals, dogs and cats, livestock and others, is steadily increasing. The veterinary profession is now saying that half of dogs will develop cancer in their lives. This is unbelievable is it not? Totally shocking. There has to be an explanation for this. 

As I said in the introduction, I have come to the conclusion that this toxic chemical accumulation is a major factor in this. It seems to me common sense that if cancer is increasing in incidence and it has been determined that dogs are eating meat containing carcinogens that this could be why it is happening.


How to deal with this? The best I have come up with is to keep the dose of these chemicals as low as possible. We can use other measures to enhance detoxification, to enhance that ability to deal with these, but keeping the dose low would be very important. 

It has been determined in people eating a plant-based diet, they are very low in accumulated chemicals, especially if the plant foods are organic. We are talking a level of a few percents, less than 5-10%, compared to the person eating the usual American diet (SAD = Standard American Diet).

There have not been as many studies of dogs and cats in this regard but some recent ones have shown that the body burden of chemicals in dogs and cats is considerably higher for some substances than it is in human beings. This can be explained from the model of the food chain, that they are at the top of the chain eating primarily the meat of animals containing these materials.


The strategy I come up with is to eat at the low end of the food chain. Eat the plants rather than the animal that has accumulated thousands of them. Fortunately, in regard to feeding dogs, it turns out that they have no problem eating such a diet. A study reported in Nature Journal of the DNA sequencing of dogs DNA compared to wolf DNA tells us that dogs have adapted to the same diet that we can eat — the use of plants and grains without any problem. They have activated the same genes that we use. 

There are also other reports of dogs being fed this way, and from puppyhood, and having good health on that diet. Fortunately, it is also our personal experience that many dogs with chronic problems — allergies, itches, ears, digestion, etc. — observably improve when the diet is changed in this direction. 

It is not so easy with cats. They are more strict carnivores than dogs. Yet, again, we have found that some cats will readily accept a plant-based diet and also have health improvements. One has to be more careful with cat recipes to make sure they have everything needed but it is very possible to do this. If nothing else, it is not so difficult to reduce the meat content in their food and certainly avoid the most contaminated meats — tuna, salmon, chickens. So many commercial cat foods contain sea fish which are high in mercury. This is a major cause of the common mouth problems cats have with decaying teeth, gum inflammation, bad breath, etc. These are all signs of mercury poisoning.


When I present this topic to people, if it is new to them, a very common response is that they feed “grass fed” or “farm-raised” animals that are not given drugs or hormones. This is a very helpful plan and would reduce some chemical exposure. However, what we are talking about here is not only the chemicals given by livestock farmers, rather what is in the environment. It is important to understand that the environment, as compared to injected materials, is the major source in today’s world.

A brief example of how even these more naturally raised livestock will have chemicals in them is the report of wildlife now being affected. One study of fawns in Montana showed developmental problems, heart defects, and other health issues in them. If this is happening to wildlife, how can we think that grass fed animals are exempted from it? 


Enough for now. I hope the explanation is clear enough. As said above, the challenge to our thinking is the realization that our world has changed. To bring up past experience of feeding practices does not address the accelerating chemical accumulation. At this point, it is not getting better so the best we can do is cope with it as intelligently as possible. We can also hope and pray that, as a culture, we will give this attention and change our ways.

Thoughts on Plant Based Diets for Dogs

I am thinking, since proposing this idea of changing the diet of dogs to a more plant based one, it would help to explain somewhat what my path to this has been. Many people when first hearing about this react with strong disapproval, saying this is both unnatural and harmful to dogs. Of course we know that the ancestors of dogs, the wolves, were prey animals and mostly ate the animals they hunted and killed. It is easy, therefore, to assume that domestic dogs should be fed the same way. This would be a good argument a couple of centuries ago, but not so much now.

The Problem

We have a problem in the dog world. Overall dogs are becoming more sick with the passing years. I am referring to numbers, percentages. Whatever our system of medicine is doing, it is not bringing about a progressive improvement of health in the dog population. One example, is the tremendous increase in cancer in dogs. Veterinarians that have looked into this say that cancer is now the leading cause of death in dogs and that some breeds like Golden Retrievers will have half of them experiencing cancer in their lives.

The Veterinary Perspective

I am giving just one example of what we veterinarians are facing in our desire to help dogs lead healthy lives. I have been a veterinarian for 50 years and I have seen a lot of change and it has concerned me. I kept looking into what might be causing this to happen (not just cancer, but the decline in health). This led me, over time, into study of nutrition, a re-evaluation of vaccine use (not an easy thing for me to do with my PhD in immunology), and working with alternative methods of treatment. I came to like homeopathy the best.


My study of nutrition opened up a whole new world. I had no idea. What I found you will see in our book along with the nutritional advice that came from my clinical experience. What is different in this last edition of our book is putting much emphasis on feeding dogs a plant based diet or a diet with mostly plant sources and minimal animal products. Many people object to this, thinking it cannot be healthy. I started out thinking the same way but my progression of learning took me to a different view.

Environmental Contamination

I learned that the environment has been very significantly contaminated by substances which are toxic when they end up in our tissues. It did not used to be like this, but with each passing year it has become greater and greater. Part of this is that more and more chemicals are being put into use. There are now 100,000 being used in all sorts of ways, most of them ending up in sewers, in the water, soil, ocean. One of the most toxic materials is the solid stuff that settles out in waste water treatment plants of towns and cities. There was so much of it that there had to be a way to get rid of it. It was expensive to put in a land fill so another solution was thought up. The sewage sludge was renamed “biosolids” and our government approved it being used as fertilizer on our food crops. So the most toxic material we can come up with, with hundreds of chemicals in it, is put on our food for the plants to take up.

It is not just this source that is a problem. As one example, industrial processing has released very extensive amounts of dioxin, which is considered to be the most potent chemical in existence that can cause cancer. Dioxin is throughout the environment, highest in fish, next in eggs, then significant amounts in dairy and beef. It is important to realize that dioxin is not something added to the food, or injected into the animals. It is in the environment, in water, air and soil. So it gets into all animals, even those raised organically.

Do you begin to see the problem? We could go on and on. After all, there are 100,000 chemicals. But you can get the idea. I realized that this contamination was a big deal and that regular feeding of dogs with sources that had poisons in them would be a very important reason whey there would be so much increasing illness.


We could talk about this for a very long time. There is actually much information available. Rather what I would like to do is bring in one more consideration and that is called “bioaccumulation.” The idea is this: the chemicals introduced into our environment are taken up by the plants as they grow. The animals that eat the plants then also get these chemicals but because they eat plant after plant, over months or years, the chemicals build up in their bodies to much higher levels that what is in the plants. Then if there are animals that eat these plant-easting animals, then they too accumulate more of it. This is sometimes called a “food chain” meaning that like a ladder the amount of accumulate chemical gets higher every rung. How much higher at the top? We are talking hundreds of thousands or millions of times more than what is found in plants. So what animals are at the “top” of the food chain and get the most chemical buildup? Human beings, dogs, cats.

Do dogs have much in their bodies? Studies of their tissues tell us that have about one and half times as much as the average human. This is a big load. Many of the chemicals are carcinogens. I will remind you that carcinogen meant a chemical that has been shown to cause cancer in animals. Do you think it possible that if a dog is eating a food that contains chemicals that cause cancer in animals that it might be a problem for that dog eventually? It may take a few years. It might show up as something else, maybe allergies, chronic ear problems, hypothyroidism. Who knows? The veterinary profession is not really interested into looking into this. Even if it were, it would involve injecting some poor dogs with the chemical for a time to see what it would do to them. A nasty thing to do.

Another Idea

How about a simple solution? I admit not a total solution but one that does seem like it makes sense. How about we just don’t feed so much of this toxic stuff to them? Once this came to my mind I had to investigate the possibility that dogs could get by eating less meat and animal products. I was surprised to find studies that showed they could do very well on vegetarian diets, even diets entirely plant based. This investigation took some time as I had my inner resistances just like most of you. But I found that dogs have the ability to eat a variety of foods and do quite well with them. They are not considered to be strict carnivores by biologists and that has allowed them to adapt to a range of diets. Studies of their ability to make enzymes used in digestion has shown us that the have the same ability as humans in this regard. They can eat carbohydrates and digest them very well.

Testing the Idea

Along the way this idea was put into action. I began to recommend to people that they make diet changes and see if there was a favorable effect. It was surprising to see that many dogs with chronic health problems, like allergies, auto-immune diseases, seizures, would noticeably improve in their health when animal products no longer part of their diet. This was unanticipated on my part but was much like long ago when I started having clients prepare their own food instead of using commercial pet foods and seeing improvements there.

Seeing better health in these chronically ill dogs reinforced the idea that this consideration of environmental contamination was an important to understand. I am not suggesting it is the only issue but seem it must be a very significant factor. Even if the chemical buildup is not the primary influence, it must be somewhat weakening to that animal wouldn’t you think?


I am going to close here. As I said above, we could go on and on with information and experience about this. I do want to communicate here that my views about this, whatever their validity, have come about because of a very long time of study and experience in the veterinary field. I started with the desire to help animals, to spare them unnecessary suffering, and this intention has remained all this time. I feel like it was this intention that prompted me to look “outside the box” and consider other ways of looking at this problem of increasing chronic health problems for our poor brothers and sisters.

Blessing to you all.

Feeding Meat

It has been, and continues to be, a very popular movement to take the nutrition of your dog (or cat) in hand and rather than feed a commercial food to select ingredients and prepare the meals yourself. This is very admirable as it is a move to freshness and a greater awareness of the quality of the food.

Along with this movement has been an emphasis on using primarily meat and bones in the meals. This is unfortunate and has led to unnecessary suffering. Starting with the first edition of our book, and continued through the recent 4th edition, we advised keeping meat in the recipes at a minimum, instead using a balanced ration including whole grains and vegetables. We did this for more than one reason and the one I want to address here first is the issue of health.

What we know is that dogs in nature eat primarily the animals they capture. From this thought one is encouraged to imitate this by buying meat and using that as a primary ingredient. What is not understood is that wolves and other dog-like animals don’t eat the meat that we get in the market. They eat the whole body of the animal they capture, not just its muscles or liver or heart. Do you see the difference? Then we have to bring in that if the animal being used as food (the livestock so called) was raised in the conventional factory farming process it will have been given a number of drugs — growth hormones, antibiotics, and parasiticides primarily. These drugs remain in the meat and are taken into the body of the animal (or person) that eats them.

It gets more complicated when we consider the food being fed to the livestock as we also have a number of chemicals in these crops accumulating in their bodies as well. How could this have happened? It is a sad story.

In this last century our human culture committed itself to practices that have, in today’s world, created very serious problems for us. With the development of chemistry substances were created, new chemicals, and they were put to use in various ways. Many of them are used directly on food crops, the various poisons against what are considered weeds and also to kill the various creatures that want to feed on these plants.

There are two things to emphasize here. First these are poisons and secondly these substances have never existed before.

That they are poisons cannot be denied as this is why they are used — to kill insects, other plants, etc. The justification is that they are harmless to us, or your dog or cat. We have learned, however, that this is relative. Yes, they are more poisonous to the insects or plants but they are not neutral in the bodies of animals. This is being found out over and over. As some of this comes out, then there might be a ban against using that particular chemical but of course then a new one is turned to — with the naïve expectation that somehow it will be different and not cause any health problems.

That they have never existed on the earth before, not for the 9 billion (or whatever) years of the time of our earth is important. I want to emphasize — they never existed before. The problem is that, because of this newness,  the various forms of life that encounter these substances are not prepared to deal with them. In contrast to the many thousands of years of evolution during which creatures learned to handle the natural toxins encountered, found ways to neutralize them, we (and the animals) don’t have a way to do this. Maybe in a couple of centuries that ability will develop but now these substances are just building up in the body , in a body that does not know what to do with them.

This is why these agricultural chemicals are so useful. When introduced there does not exist any way for the plants, insects to avoid being affected by them. Yes, they are learning to do it, but the extraordinary usefulness of these chemicals is because of this newness. And it is this newness that is creating problems in the bodies of the animals that live with us.

(to be continued — environmental toxins)

Feeding grains to dogs and cats.

Since the 3rd edition of our book was published in 2005 there was a strong movement towards feeding dogs and cats primarily meat and bones. This was called a “raw food diet.” The strange idea was put forth that grains are harmful or poisonous. Likely this is an exaggeration of the concept that grains in large amounts are not the optimal diet. The situation is more complex, however, than most realize.

The first question is if grains are not good for animals. The short answer is that grains are well accepted by animals if they are properly prepared. By this, I mean that the animal digestive tract is shorter than the human so the grains must be well cooked to be digestible.

Well, then, are they are in some way harmful? They are not if the quality is good. By “quality” we are meaning that the grains are complete, not just “leftovers” from milling. Also they need to be fresh, not rancid or spoiled. One would assume this is obvious but the fact is that commercial pet foods can use the leftovers and rejects from the production of human foods — the spoiled, contaminated, nutritionally inadequate floor sweepings — as their source of grains. Much of the concern about the harmful effect of grains in food for animals is because of the poor quality grain used in many commercial pet foods. The formula is like this:

Poor quality grain in commercial food = diminished health in animals = avoidance of grain based commercial foods = all grains are bad.

You can see that the first 3 steps make sense but the last conclusion does not as it is not taking into account that the health problems seen in animals has to do with the quality of the ingredient rather than the nature of it, e.g. that it is from grains.

Research into animal nutrition as cited in “Nutrient Requirements for Dogs” and “Nutrient Requirements for Cats” published by the Subcommittee on Dog Nutrition and Cat Nutrition by the National Research Council (about as reliable as one is going to find outside of the industry) reports that growing dogs fed a diet of up to 62% starch (which is an unusually simple carbohydrate, grains being much more complete) were able to digest 84% of the starch and use it for growth and energy. Even more significant these puppies had no apparent health effects from such a diet, growing the same as the group fed no carbohydrates. Cats have been shown to be able to digest over 96% of starch fed to them.

Another factor to bring in is that whole organic grains are very nutritious and compared to meat or other animal products have a fraction of the environmental toxins found in the tissues of animals. The animals that eat plants, drink the water available, and accumulate huge amounts of toxic substances, many hundreds of chemicals, that build up in their bodies. It is not so much that plants are completely free of these because our environment is so contaminated, but the amount in plants is like 1-2% of what is in animal tissue. The animals eating these plants day after day (or GMO soy or corn) accumulate this in their bodies. Then when their bodies are eaten by others, those that eat them again accumulate thousands of greater quantities of these chemicals in their tissues. This build up each step of the food chain is called bioaccumulation.

We discuss this in detail in the 4th edition of our book, Dr. Pitcairn’s Complete Guide To Natural Health For Dogs and Cats, published by Rodale Press. It is now available from booksellers.