Understanding environmental veterinary medicine

Exposure to toxins, stress, poor diet and other external influences can play a major role in the development of many disease states. Here’s how environmental medicine can help.

Environmental medicine evaluates and identifies potential environmental exposures that may lead to a disease condition. Therapy is aimed at eliminating the cause or reducing exposure, and resolving symptoms through nutritional support and reducing total body stress (physical, emotional, mental). The ultimate goal is to reverse pathophysiology and restore health without necessarily increasing drug load.

Several terms are used when discussing environmental medicine.

• Xenobiotic refers to a foreign chemical that is absorbed by the body (potential toxicants). • Detoxification refers to the process by which the body reduces the xenobiotic to a form that can be eliminated or stored.

• The enzymatic system that detoxifies dietary compounds and xenobiotics consists of phase I (oxidative) and phase II (conjugation) reactions in the liver. Many pathways can be used to detoxify a particular compound. If a pathway is overloaded or the enzymes are being used elsewhere, the chemical can be metabolised into a different metabolite or stored in lipids, later leaking back into the bloodstream.

• Toxic load refers to the total body burden of stressors that lead to disease. For example, a dog with atopy may have food, chemical (insecticide, hydrocarbon), inhalant (mould, dust, pollen) and stress (separation anxiety) overload as triggers for expression in addition to immune defect.

There are a number of influences to consider in understanding the total body burden for an individual dog. The following list is not complete but for consideration in a particular case. It doesn’t matter whether the treatment is conventional or complementary/alternative, the same approach helps determine contributing factors, and by addressing them, minimize their negative impact on health.

1. Domestication

Wild dogs roam in packs, but the domestic dog often spends all day in a small backyard, often on his own. Wild dogs are free to mate, and the strongest survive, but domestication and selective breeding has brought with it genetic conditions and inherent weaknesses. Whereas wild dogs hunt or scavenge and are occupied with survival, the indoor pooch is provided for, and fed anything but the carcasses of prey or scavenged food.

As dogs were domesticated, they were subjected to these conditions . And while domesticated dogs certainly live longer lives (70% of wolves die each generation), they are now prone to the scourges of modern living — degenerative diseases like arthritis, heart disease, cancer, allergies and chronic skin problems. Dogs can no longer be compared to their wild counterparts. They have been changed radically through their lives with us. They no longer have the same coloring, markings, shape, body size, anatomy, physiology and behavior as their wild cousins do.

2. Free radicals

Many lifestyle factors affect our health — high fat diets, not enough exercise, too much alcohol, smoking, drugs and stress. Dogs also suffer urban stress.

One of the simplest reasons dogs get sick is because they are domesticated and live in urban environments where they are exposed to free radical attack from many sources. Free radicals cause damage and lead to disease in a very insidious way. UV radiation from thinning of the ozone layer, radiation, microwaves, x-rays and magnetic fields are all possible contributing factors. Furniture and coverings on walls and floors are constantly emitting free radicals as the residues of chemicals used in their manufacture degrade. Cigarette smoke contains one of the densest free radical sources — even third hand smoke residues on clothing can impact animal health! Even excessive exercise can boost naturally produced free radicals in the body .

While animals are young, their antioxidant enzymes concentrations are high enough to absorb and counteract most free radicals in the body. With aging, however, the effectiveness of these protective systems slowly wears down. More and more free radicals survive and cause damage to tissues, and over time they wear out the body. The lifelong exposure to free radicals causes the degenerative or “wear and tear” changes associated with aging.

All this is compounded by the fact that many dogs, like many people, usually eat too much and have poor quality diets, and exercise too little.

Free radicals and disease

The accumulation of free radical exposure has been implicated as an underlying and important contributor to many diseases, especially degenerative conditions such as arthritis and heart disease, as well as disorders of the skin, eyes, digestive tract and the immune system.

3. Stress

Probably the most overwhelming influence on a dog’s health is stress. Stress causes the release of catecholamines in the alarm stage, and both catecholamines and cortisol in the resistance stage. Exhaustion, chronic stress or dis-stress can occur as a result of the side effects of chronic catecholamine and cortisol release. Ask the owner when a chronic series of problems began. Was anything significant happening in the family or in the life of the dog that may have been particularly stressful, emotionally? Is the household harmonious now?

4. Nutrition

Nutrition has a major impact on the health and well being of the dog. Needless to say, the ability of a dog to cope with stress and function optimally is influenced by the quality of his diet and the availability of nutrients and energy. Good nutrition contributes greatly to the vital energy of the body, helping it to keep in balance. On the other hand, poor nutrition or the inability to utilise nutrients contributes to poor health. A nutritional intake is important in the history taking — not just what the dog eats, but his snacks, bones, fresh foods, etc. This helps uncover possible contaminants, malnutrition issues or toxins that might not be apparent to the owner.

5. Parasites

Fleas and internal parasites are a natural part of most companion animals’ lives. Generally, a healthy animal will be able to cope with a small natural burden of parasites. A dog already depleted in energy will be less able to cope. Again, an environmental medicine approach that reduces the need for chemical use is preferable for treatment, regardless of whether parasites exist or not. Find out what is being used and how often.

6. Lifestyle

Lifestyle plays a significant role in the dog’s health. A sedentary animal is more prone to obesity, lethargy, boredom and behavioral problems. Animals need physical and mental stimulation if they are to achieve optimal health. It’s worthwhile finding out if members of the human family have problems; often there is a correlation between disease states in animals and their owners. Owners who are out all day, rush home, eat fast food and are stressed may overtly affect their pet’s health too.

7. The outdoors

Carbon monoxide from car exhaust fumes, air pollution, ultraviolet light from the sun, low grade radiation, toxic chemicals from weedicides, floor cleaners, insecticides, and fumes from paint abound. A healthy animal can usually cope well with such insults. The body adapts and works to detoxify foreign substances on a continual basis. However, for an unwell animal, pollution and free radical damage can further contribute to poor health.

8. Veterinary care

Most dogs benefit from conventional veterinary care. Their diseases are fixed, prevented and managed. But some animals simply do not get better or cannot cope with normal care. They may need a lifetime of treatments to suppress or manage the symptoms of chronic disease. Their bodies are already so overwhelmed and stressed that additional drugs or treatments may overload them, making them sicker and unable to return to a normal state of health. Consider vaccination load, flea treatment, heartworm treatment, wormers, shampoos and other common products. What is essential, not from a conventional practice policy point of view, but for this individual patient? What is the benefit and risk for this patient? Can we delay the use of some of these chemicals or drugs until the animal is well?

To learn more about environmental medicine visit www.civtedu.org/environmental-animal-health.


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