Anti-fungal Supplements for Hoof Diseases

by Bob Peacock © 2000

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Published in the March 2000 Issue of Anvil Magazine

Over the past few years a number of feed supplements have been developed to address specific needs for horses. While lacking definitive scientific support, at least as far as serious research may demand, these supplements have proven to be beneficial.

Through the process known as cause and effect, specific cases have exhibited positive results in conjunction with nutritional support. Some are quite subtle, others rather dramatic. The bottom line is that, in many cases, a process of systemic recovery holds no claim other than the supplements themselves. This is not to infer that a magic bullet exists, for it probably doesn't. What it does indicate is that nutrition, particularly case-specific support, has been overlooked in treating chronic laminitis and white line disease. A number of testimonials have been collected which, although certainly not scientific, are nonetheless pertinent, particularly given the nature of a disease that has perplexed and confounded the best authorities available. Farrier Science Clinic developed, documented and sent out surveys on 285+ horses through ANVIL Magazine and at clinics nationwide. These were received from veterinarians, horse owners and farriers. All support the findings that the immune system is violated and supplementation can be used for treatment. This is being clinically proven by research projects now underway.

Horses need:

1. Water - it makes up over 50% of their body weight

2. Protein - made up of amino acids
a. 23 total amino acids
b. 10 essential amino acids
c. dl-methionine is the most important amino acid for hoof growth. It helps prevent edema and various infections, and works with choline to fight against tumors.

3. Fats - an energy source for the horse. Fats have 2.25 x more energy per gram than proteins or carbohydrates.

4. Minerals
a. Calcium and phosphorus
b. Magnesium
c. Sodium, chloride and potassium
d. Iodine - stops the spread of fungus and dreaded bacteria and viruses in the hoof and skin. Certain amounts work through the thyroid gland to produce helpful bacterial antibodies needed for good health.
e. Trace minerals. One of the most important is zinc. It helps
promote tissue growth at a faster rate. Helps fight infections.
f. Inositol - Helps to properly utilize choline. Promotes healthy hair, hoof and bones.
g. Selenium - A mineral essential in promoting hoof growth and quality. It is also required for proper muscle function and endurance. Selenium possesses anti-fungal qualities.

5. Carbohydrates
a. Starches
b. Sugars
c. Glycogen

6. Vitamins
a. Fat soluble: A, D, E, and K
Vitamin A - promotes tissue growth, strong bones, hoof, healthy skin, hair, teeth and gums. Helps build resistance to disease.
Vitamin D - Helps properly utilize vitamin A, calcium, phosphorus. Necessary for strong bones, teeth and hoofs.
Vitamin E - Helps to retard cellular aging; an anti-oxidant. Supplies oxygen to the cells for better endurance. Helps fight fatigue, accelerates healing and growth.

b. Water soluble: Thiamine, riboflavin, niacin, vitamin C, pantothenic acid, pyridoxine and biotin.
Niacin - Helps increase circulation of blood to areas of the body for faster healing and growth.
dl-biotin - Second most important nutrient in hoof growth and repair. Helps alleviate eczema and dermatitis through utilization of proteins.
Choline - Helps eliminate poisons from the system by aiding the liver; helps nerve response to aid the healing.

Hoof Growth and Nutrition

1. Normal growth
Foals, .5mm per day - 1" in two months (and more, with increased work and/or exercise)
Older, .2mm per day - 3/8" in 1 month (and more, with increased activity)

2. Factors (ailments/diseases) that cause increased hoof growth
a. Laminitis
b. Cracks
c. Abscess
d. White line/hoof disease
e. Trimmed too short
f. Hoof and leg imbalance

3. Factors that affect rate of hoof growth
a. Blood flow to coronary band (affected in part by exercise)
b. Nutritional factors: Controversial in the area of feeding a deficient diet vs. excess feeding

4. There are several nutritional factors which are important to normal hoof growth. The protein structure of the hoof is loaded with sulfur-containing amino acids, so elemental sulfur is important to normal hoof growth. The sulfur-containing amino acids methionine and cystine are two of the more important ones to horses. Methionine is known to be necessary for keratiniza- tion of the hoof wall. It helps increase the bond between the lamina and therefore used to treat foundered horses.

In addition to sulfur protein, calcium and the vitamin biotin are very important to normal hoof growth. Calcium, in the correct ration with phosphorus (1.5:1 to 2:1 calcium), is important for hoof quality. Biotin is known to improve hoof quality and rate of growth.

The Equine Immune System

The horse's immune system is affected by the following factors:

1. Genetic Potential
Conformation and the effect on hoof function
a. Stress
b. Alignment - balance

2. Environmental Factors
a. Housing
b. Environmental control: heated barn, wood shavings
c. Cleanliness of the stall
d. Exposure to chemicals in the environment
e. Proper nutrition or the lack of it

3. Activity Level
a. Use of the horse
b. Activity when not being used or ridden

4. General Health
a. Regular health maintenance
b. Any ongoing disease processes that affect the resistance to other diseases

5. Effects of Drugs
a. Any necessary or unnecessary medications and their effect on the immune system, positive or negative.
b. Over-medication and excessive deworming
c. Over-supplementing the horse's diet (playing doctor with your horse)

Adequate Nutrition

Adequate nutrition, with its necessary building blocks for healthy hoof, has never been demonstrated alone to increase hoof growth or the quality of the hoof. However, whether the nutritional requirements of your horse are adequate with respect to these essential components is another question. There is strong evidence that lack of meeting the nutritional requirements with respect to protein and other essential components will have a negative effect on hoof growth; it has been shown that in weaning-age ponies being fed a nutritionally deficient diet, there can be as high as an 80% reduction in hoof growth.

A mature horse's foot grows on average of 0.25 to 0.35 inches per month. This growth rate varies seasonally and is the slowest when the weather is the hottest or the coldest. Some of the suspected predisposing factors include: excessive moisture/drying, lamellar damage (laminitis), acute trauma, abscess development, hoof cracks, excessive toe length, and, as noted, nutritional deficiencies.


The nutrients mentioned here should be fed in balanced and proven proportions. Professional advice should be followed from professionals such as a veterinarian and a nutritionist, along with your own use of common sense. Remember that more is not always better.

The Spread of White Line Disease

The questions remain:

1. Is this disease/syndrome a primary or secondary infection with bacteria, fungi, or both?

2. If it is secondary, to what degree are the predisposing factors causing a weakness in the integrity of the hoof wall? Feed companies closely monitor fungal activity across the United States. When fungal activity increases, additional amounts of calcium propionate, a fungistat, is added to the feed to keep the fungi in check. This prevents fungus from damaging bags of feed in storage and avoids huge replacement costs on the feed companies' part. A marked change was noticed 15 years ago when a series of hurricanes swept up the east coast from Florida, then swept into New England and the Midwest, carrying millions of tiny fungal spores in the winds. Particularly in the past five to eight years, conditions have been excellent for both the spread and growth of such fungi. This period coincides with the time of the outbreak of the "white line" or hoof wall disease epidemic. These fungi and yeast are nothing new. It just so happens that, in nature's cycle, there is an abundance of fungi spread throughout areas of the country where they weren't normally found in such large numbers.

The second environmental factor that helps fungi, such as Pseudallescheria boydii and Scopulariopsis (hoof wall infection) is that of acid soil caused by acid rain. The presence of acid rain is a major problem in many parts of the world. Its deleterious effect on much of the environment is well documented, and these fungi thrive on acid soil. Acid rain, warm, moist conditions, and favorable winds add up to an explosion of the fungi population.

Another source of increasing the fungi population is the decrease of the pH level in the stalls caused from the excrement (waste matter discharged from the body) of the horse. The urine excretes an excess of the needed nutrients fed to the horse, decreasing the pH level. Over-feeding of alfalfa hay can increase the ammonia on the stall floor, which decreases the pH, and increases the fungi spores. To change the environment of the horse's stall, lime it. The lime will raise the pH of the stall and make it more difficult for the fungus to grow there. It is beneficial to open and air out stalls for 24 hours or more. This will also raise the pH level. It comes down to good housekeeping. The horse should be kept on clean, dry footing. Then the horse's diet can be evaluated to see if it is getting a balanced ration, including all essential amounts of protein, vitamins and minerals.

What Nutrients HELP?

Many nutrients that affect hoof growth and quality (vitamin A, vitamin E, calcium, lysine, selenium, and zinc) are frequently lacking in equine diets. Just making sure that the horse has free access to a loose salt-mineral-vitamin mix (containing calcium phosphorous) will prevent most deficiencies.

Treatments that were Used and have had Positive Effects on Controlling Hoof Wall Infections

Three nutrients are particularly noteworthy: vitamin A, vitamin E and selenium. They are all likely to be below levels in many horses' diets, depending on the feed formulation and the area of the country. It is generally helpful for the horse to take in about five times the National Research Council's levels for vitamin A, vitamin E and selenium. These three nutrients may well be the solution for the horse that, after months or years on biotin or other hoof supplements, still has bad hoofs. Conversely, if after six to eight months on a balanced ration (with extra vitamin A, vitamin E and selenium) the horse's hoofs are not good, then it may pay to experiment with additional protein or lysine or sulfur or biotin, or one of the multiple-supplement products. As the role of nutrition in the equine is explored, we must take special care in evaluating each horse as an individual. Its environment, age, temperament and exercise program, as well as the generally available feeds, can all be brought under consideration when we work to improve hoof growth and quality. Another thing that happened during the 1980s in the horse industry was the introduction of paste deworming. As current data from the previously mentioned survey and indicate, 88 percent of the owners and trainers deworm their own horses. This is economical and time-saving. The method and the intervals between deworming is questionable. And, more often is not always best. Types of dewormers should be rotated under a veterinarian's instructions and also follow the manufacturer's instructions. An interesting comment was made by a veterinarian: In the 1970s the fecal samples, when tested, came back with some small amounts of larva in the stool. Today's wormers, however, are 100 percent effective. This raises a question: Is it possible that some of the bacteria normally present is also being eliminated by not following the veterinarian's and manufacturer's instructions?

Author's Notes:

Enzyme preparations and potassium or sodium iodide, given to horses orally - 4 gm. to 10 gm. - is the recommended daily dose for two to four weeks. Discontinue medication if signs of iodism appear (eyes watering at lids or nostril).

This was used in a 65-horse stable with success and no side effects. The maximum dosage for mares in foal is 40 mg. There is a multi-supplement that contains 10 mg. per oz. in one formula and 20 mg. per oz. in another formula made for horses with laminitis and white line problems. This has been an effective anti-fungal concentrate in all horses on which it has been used to date.

I had an interesting talk with four men from Argentina - each was a veterinarian and farrier combined. They don't use lime in the stalls and receive most of their feed from North America. They were also concerned about the acid rain. They asked what preventive methods were being used here. This was one of the main concerns for everyone.

I say look at the cause, not the symptoms. More research has to be done with more people getting involved. This means the veterinarians and manufacturers as well as the general horse public. From the 298-horse survey taken a few years ago, it was found that 68 percent of the horses that had hoof problems were being fed sweet feed.


"Shelly Feet" by Dr. Michael A. Ball, DVM
"Look at Basics" by Dr. Jon Cohen, DVM
"Nutrients that Affect the Growth and Quality of the Hoof"
by Henry Heymering, ANVIL Magazine June/July 1993
Management Report #6: "White Line Disease," American Farriers Journal
"Hoof Wall Problems & Solutions: A New Threat" by Bob Peacock, published in ANVIL
Magazine, 1993. (Editorial Review by Burney Chapman, same issue)
"Feed Supplements for Healing" by Andy Juell. ANVIL Magazine, 1998.
Testimony of Methods Used to Avoid Hoof Wall Disease submitted by Henry Heymering, CJF, RJF

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