Many persistent hoof wall diseases fade away when treated with a combination of topical disinfectant and proper nutrition, according to a recent study.
Veterinarian Susan Kempson of the Royal (Dick) School of Veterinary Studies, University of Edinburgh, at Edinburgh, Scotland, and farrier Ruaraidh Robb used topical disinfectant and a hoof-building diet during the year-long treatment of 23 horses with serious hoof problems. Kempson and Robb, writing in the Veterinary Record trade journal, report that 22 of the horses “improved greatly within 3 months of starting the hoof-care program.”
The researchers say the two-pronged approach to restoring hoof health is needed because both diet and microorganisms — bacteria and fungi — have been found to play a role in hoof wall diseases.
Kempson and Robb note that previous research demonstrates that a correctly balanced diet and supplementation program provides limited horn improvement if the wall is heavily infected with microorganisms. Likewise, they say, topical disinfectant can’t eliminate all infectious organisms from the hoof wall, so new horn growth is needed to overwhelm the residual infection.
Various Ailments Cured
The horses treated and studied by Kempson and Robb suffered from white line disease, thrush, abscesses, coronitis, crumbling horn and cracked walls.
Initially, topical disinfectant was applied to the hooves daily using a toothbrush to work the material into cracks and crevices. After the diseases were controlled, disinfectant was applied each time the hooves were dressed, rasped, trimmed or shod.
The active ingredients in the topical disinfectant were a poloxamer-iodine complex, ethylenediamine dihydriodide, isopropyl alcohol and propylene glycol. The carrier fluid for the active ingredients was distilled emu fat for half of the horses, and tea tree oil for the other half. The brand used was Life Data Hoof Disinfectant.
Working with the horse owners, the researchers also balanced the animals’ diet for calcium and phosphorus, using alfalfa as a source of calcium and fiber. Horses with lots of grain in their diet were especially targeted for alfalfa, and horses with a history of laminitis were given a high-fiber, low-carbohydrate ration. The researchers also added a supplement meant to promote high-quality horn growth.
Also, bran and supplements containing selenium were removed from the diet. They note that selenium is the most toxic of the essential trace elements, and chronic selenium toxicity can lead to hoof pain so severe that affected animals refuse to move.
At the start of the study and every 6 weeks afterward, hoof wall samples taken from trimmings were microscopically examined. Initially, the hooves of all 23 horses showed heavy bacterial infection, and eight also suffered from fungal infections. The authors note that the exact role of bacteria and fungi in hoof wall diseases is unknown, but it is likely that these microorganisms must be reduced to restore high-quality horn.
Kempson and Robb say that after a short period of treatment with the hoof disinfectant — designed to work against bacteria, fungi and their spores — the horses began to grow good quality hoof horn. The horses were then able to wear shoes for 4 to 6 weeks, instead of just days, and could perform normally. The improvements were maintained for the 12 months of the study.
The researchers point to several horses as indicative of the success of the treatment program. Among them:
Horse 1 had a major breakdown of the dorsal wall on all four feet. Bacteria were found in the intercellular spaces of hoof wall samples, and the spaces were enlarged. The outer layer of the wall had broken away in the area of the nail holes to reveal black, necrotic tissue in the inner layer of the wall. The wall was crumbling and necrotic.
Six weeks after the first application of topical disinfectant, the appearance of the feet had improved significantly, although there was still blackened tissue in the white line and the wall near the nail holes. The texture of the dorsal wall had improved, too, and the horse retained its shoes for 6 weeks.
After 12 weeks of treatment, there was no evidence of the diseased horn or any discolored horn around the nail holes. Microscopic inspection found no evidence of bacteria. The intercellular spaces were still larger than normal, but the horn showed a more cohesive structure.
Lame To Healthy
Horse 2 had been used for pony club activities, including dressage, cross-country and hunting. It became severely lame in all four feet with severe thrush. The frogs were unrecognizable and merged with the soles. The palmar and plantar surfaces had a yellow, cheese-like consistency with hemorrhagic foci and a strong, foul odor. The coronary bands were crusty and would bleed when bumped. The proximal dorsal walls and the heel bulbs were also crusty, and the bulbs frequently bled.
The horse had been given phenylbutazone to relieve pain. Various topical treatments had been tried, including a crystal violet antibiotic spray and standing the horse in a 10 percent formalin solution, without success. The researchers found that the horse had been receiving a supplement of selenium for 6 years.
Five days after the start of the researchers’ treatment program, the hoof dressing could be applied without using a twitch. After 2 weeks, the phenylbutazone dosage was progressively reduced and the hooves were trimmed. Large numbers of bacteria were found within the hoof walls and the tubules were badly distorted.
Just 8 weeks after the start of treatment, a microscopic exam of hoof wall samples found far fewer bacteria, though damage to the horn cells was still evident. The horse continued to improve, and after 4 months it was turned out for grazing and exercise. Six months after beginning treatment, the horse was shod and resumed pony club activities. The coronary band, perioplic horn and heel horn were normal and did not break down when bumped or grazed.
After 18 months of treatment, the horse’s feet appeared completely normal and no further treatment was required.
22 Out Of 23
Kempson and Robb say these two examples represent the healing shown by 22 of the 23 horses in the study. Both bacteria and fungi within the hoof wall were quickly and greatly reduced by the topical disinfectant, while the diet and supplement adjustments promoted good-quality horn growth to replace damaged tissue from within. The feet of the 22 horses improved greatly within 3 months of starting the treatment program, they say.
They say the 23rd horse improved a little with treatment. It suffered from coronitis and had metabolic problems, and its hoof wall showed evidence of long-term selenium toxicity. It was lost to the study after 12 months.