Nutrition
Keeping Your Horse Fit
BASIC CONCEPTS in Nutrition

NEWS & VIEWS by WALT OLSEN

Here in Washington State the 2005 ride season is under way with our first ride on Feb. 26th under nice and sunny weather with the temperatures in the low 60's. Noella Novarra and her daughter Donna Amos were the ride managers and they put on a wonderful ride with 43 riders turning out for this ride.

The morning started out foggy and by starting time the fog was burning off and a gentle breeze came up, the sun came out and most of us were gone by about 11:00 a.m. for a trek through the woodlands, the area which we were riding in is the area if you check out the story on the web about the robbery is where we were.

Six new folks joined in for this event and were very excited about this sport.

I watched a new team with a very young boy riding and having a wonderful time as he was in front as they traveled down the trail going pretty fast.

My wife and I rode the short course that proved to us that it takes good eye sight and determination to find the Objective Stations, but doesn't help when we both have bifocals and of course with the sunshine causing our photo tinted glasses to

be dark for part of the time. I guess I am going to have to try harder.

Once again comes the next part of my continuing series concerning what to look for with your riding friend (horse) and how to keep them sound for riding; in this segment we are going to look at diseases of dietary origin. Eating the wrong foods (or the wrong amounts of the right foods) can have bad consequences in your horse.

"You are what you eat" does have a bearing upon the case to horses with regard to health and well being. Although horses have evolved to eat plant material, not all plants are safe to eat. Some food substances directly exert toxic effects, while others grow fungi that do so. Availability and type of food are important issues to intestinal health and nutritional balance.

In addition, imbalances of nutritional compounds such as micro-minerals, energy, carbohydrates, and protein can have adverse effects on your horse's health. In young horses musculoskeletal problems can occur, one is called (DOD) or developmental orthopedic disease resulting from a variety of multi-factorial issues, but nutritional imbalances are known to strike a young growing horse. DOD is linked to an imbalance of calcium and phosphorus, and /or a deficiency in micro-minerals such as copper, zinc, and manganese; over feeding of these minerals can cause is just as likely a cause as imbalanced nutrition in stimulating this disease.

Too many calories enable a growing horse to become fat, with subsequent overload of developing joints. Hormonal changes associated with a rich diet also can affect joint metabolism. Mineral imbalances have destroying effects on joint cartilage development. It is known that high phosphorus and relatively low calcium levels will cause cartilage defects. High zinc levels can suppress copper absorption and result in a diet that is relatively deficient in copper.

Adverse effects of an imbalanced diet are amplified by other high-risk factors. The potential for rapid musculoskeletal development is dependent on genetics as well as on nutrition. Rapid growth adds stress to a growing skeletal system, bones, and joints when they can least withstand the added body mass.

A diet deficient in selenium can create muscle problems. The NRC (National Research Council) requirements list the required amount at 0.1 mg/kg of the diet. Foals might exhibit stiff and painful muscle disease and cardiac problems, while older horses have recurred episodes of tying up. Selenium deficiency occurs in certain geographic areas such as the Northwest and northeastern United States. However, caution must be taken not to supplement with too much selenium as toxicity can occur. The maximum tolerable level is 2 mg per kg of the diet, according to the NRC.

Some of us add to the lack of selenium here in the Northwest by putting

selenium salt blocks in a free choice area to keep our horses from chewing wood or bark off of trees that may be in the pasture areas. The adverse effects of too much selenium could trigger several adverse effects, including colic, diarrhea, hair loss and separation of the hooves from the coronary band.

Moldy corn poisoning, also known as blind stagers, is associated with consumption of corn that has been contaminated with the fungus Fusarium moniliforme. This fungus thrives on corn plants that have been stressed by drought, disease, or insects prior to harvest. High humidity and moisture encourage the growing of this mold. Exposure to high doses of this fungus over a short period of time results in liver toxicity; while low doses ingested over a longer time result in brain damage or moldy corn poisoning. Signs to look for include decreasing appetite; changes such as depression, anxiety, and neurological signs such as circling, blindness, difficulty chewing or swallowing. It's time to call your Vet. Do not wait!

Another problem that causes death in your horse comes from Botulism in the dietary form and occurs in horses which have ingested feed contaminated with this toxin produced by the bacterium Clostridum botulinum. The toxin forms when a decomposing animal or bird is accidentally baled with the hay or is processed with pelleted or cubed feed. Haylage or silage that is improperly prepared without sufficient heating allows for continued decay of organic material and production of the toxin. Moist or rotten hay, especially legume hay, can also spawn growth of anaerobic bacteria responsible for generating the toxin. Botulinum toxin is extremely potent and lethal resulting in death. Check you bales of hay for critters that might have been included in your hay when you bought it. If you bought it from a feed store, gather all you bad hay up and take it back; if you bought off a truck on the side of the road, then you are most likely to be stuck.

Skin problems can be caused by plant ingestion. Certain plants contain photo reactive pigments that are absorbed into the blood when a horse eats the plants. In the presence of ultraviolet light from the sun, these then react in areas of non-pigmented skin, and the horse sunburns. Two main plants are the problem in this situation: St. Johns wort (Hypericum perforatum) and buckwheat (Fagopyrum esculentum).

Other bad plants are and will cause problems to the liver and can cause death if taken in large doses are: Tansy ragwort or groundsels (Senecio spp.), hound's tongue (Cynoglossum spp.), horsebrush (Tetradymia spp), alsike clover (Trifolium hybridum). Legume hays have also been implicated in setting up these conditions for skin problems.

Respiratory problems other wise known a chronic obstructive pulmonary disease (COPD) can be caused by various allergens. Like an asthmatic person, a horse can be afflicted by respiratory allergies that come from mold and mold spores in hay. Poor quality roughage or hay that has high moisture content is prone to mold growth. Or hay that has been sprayed with a preservative to keep it from molding as is the case of most of the alfalfa being shipped out in containers from Washington State to Japan and points east. In that case if the hay is rejected by brokers for overseas shipment then that hay comes on the local market it must be soaked to get ride of the preservative before you can use it. A large flake of hay soaked for several hours will turn the water red; it is then safe to feed.

When a susceptible horse is exposed to these molds, a cascade of inflammatory events begins in the lungs. The end result is an emphysematous-like condition known as COPD or inflammatory airway disease (IAD), historically called heaves. What might start as an intermittent and infrequent cough can become more persistent as more lung tissue is affected and the lower airway becomes more sensitive to the effects of environmental allergens. It is not just presence of dust and mold that causes the COPD syndrome; respiratory viruses or chronic respiratory infections also create similar damage.

Fescue toxicosis occurs when tall fescue, a common pasture and hay forage for horses throughout the United States and Canada, is infected with a fungal plant parasite that lives on another parasite and causes a fungus; creating problems with our friend the horse.

Knowing the risks that these and other feeds pose to you horse's health is the first step to avoiding problems. You should discuss local plant/hay/feed risks with your local county extension agent and your veterinarian so that you can formulate a plan of action to remove any dietary problems from your horse's diet.

This material was taken from research material supplied by WSU, School of Veterinary Science, Pullman WA, and from material obtained from the UC @ Davis CA