4 Bar Z

Information You Should Know

• What is Equine Thrush
• What is Laminitis?
• White Line Disease
• White Line ~Treatment

What is Equine Thrush?

Equine thrush is caused by anaerobic bacteria that, when trapped in moisture, can create a fungal infection that slowly eats away at the horse's hoof tissue, particularly the frog area. Most of the time this will create some mild discomfort. Left unattended for a period of time the thrush can eventually make its way into the sensitive areas of the frog, causing a bit of bleeding from the frog.

Many horse owners become a bit gun shy with a horse's hoof and create false diagnoses of thrush the moment they notice a peeling frog or a strong scent. Peeling frogs or soles are not abnormal, and generally occur when a horse is due for a visit by the blacksmith. In addition hooves are capable of trapping foul smelling bacteria, manure, etc., so an unappetizing scent during hoof cleaning isn't uncommon at all.

A hoof that is afflicted with thrush will exhibit soreness, black pus-like liquid as well as a scent that can send a skunk running. If you detect these symptoms you can either attempt to treat it yourself or call us to assist you. The bacteria that causes thrush is anaerobic, which means it cannot survive when exposed to oxygen. As long as you keep his stall shavings clean and dry as well as clean his feet with a pick regularly, the bacteria will be deader than a doorknob before it can even think of taking hold in your horse's frog. It's one of those common ailments that should be rare since a clean environment and air is enough to keep it away.

If thrush does manage to creep up on you and your horse, don't worry - treating it is actually fairly simple. I suggest first calling your farrier so that he can thoroughly clean and trim your horse's hooves (particularly the frog area). This will make it far easier for your horse's hooves to aerate, plus you can apply medication more directly to the infected areas.

Two products that are highly regarded by farriers for their effectiveness are Kopertox and Thrush Remedy by Absorbine, but just squirting some on the hoof generally isn't enough since the liquid may not reach all the nooks and crannies of the infected frog. Instead of squirting those products onto the infected area try applying the medication with a cotton swab. (Wrapping cotton around a stick or hoof pick does the trick.)

Thrush can be a dirty, smelly business to deal with, but luckily as long as you do not neglect it your horse will suffer no long-term problems. Of course since thrush is so easy to prevent just by keeping clean stalls and clean hooves, chances are high you'll never once be introduced to this black-hearted monster.

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What is Laminitis?

What is laminitis? Is it the same as founder?

Laminitis, commonly called founder, is an acutely painful inflammation of the foot. It occurs most often in the front feet although it can affect the hind feet as well. Founder is the name given to the resultant tissue damage and complications following one or a series of acute attacks of laminitis.

In the worst case, permanent damage to the laminae can result and the attachment of the coffin bone to the hoof wall breaks down. The whole weight of the horse bears down on the coffin bone, and without the attachment to the hoof wall, the bone rotates down and can actually be pushed right through the sole to the ground.

What are the symptoms of laminitis?

If just the two front feet are affected, the horse will stand in the "founder stance" with his hind legs well up under the body carrying as much weight as possible, and the front legs placed forward with the weight on the heel. He will be reluctant to walk and will turn by leaning back and pivoting around on the rear legs.

If all four feet are affected, the horse will lie down for extended periods and may refuse to get up. If forced to stand, he will pull his hind feet and fore feet in toward each other under the centre of his body.

Other symptoms include heavy breathing and glazed eyes due to pain. The feet will feel hot and the digital artery, located over the fetlock joint, will have a pounding pulse.

Each attack of acute laminitis can leave a ring formation on the hoof. A horse suffering from chronic founder will have multiple rings on his hooves. He might also have seedy toe, a separation of the hoof wall from the sensitive laminae in the toe area. If left untrimmed, the hoof wall also overgrows to form a "slipper foot".

What causes laminitis?

Many different situations can cause laminitis. Grazing on lush pasture (particularly overweight horses), overloading on grain, eating lawn grass clippings, or drinking large amounts of water when overheated can all cause a horse to founder. Other causes include a mare retaining the afterbirth, hard or fast work on a hard surface or standing too long on a hard surface, and stressful situations such as colic.

What should I do if my horse has an attack of laminitis?

The first thing to do is identify and remove the cause of the problem and call a veterinarian. Treatment is given to relieve pain and reduce swelling and the horse is put on a carefully monitored feeding program. X-rays of the feet may be required to monitor progress.

Long term management of a horse with founder requires careful attention to feeding to prevent a recurrence. The horse will probably have to be kept off pasture and fed hay. To keep the foot in as normal a shape as possible, corrective trimming at regular intervals by a farrier will be necessary. Corrective shoeing might also be indicated.

Chronic cases can be kept reasonably sound by proper trimming and shoeing and a sensible feeding program. However, if the horse cannot be kept pain-free, euthanasia may be the kindest option.

How can I prevent my horse from getting laminitis?

Laminitis is a disease that can be avoided by following proper horse management.

Avoid feeding excesses and keep your horse at a reasonable weight. Watch for and avoid grass blooms on pastures; pull horses off the fields and onto dry lots if necessary. Feed hay in the morning and turn horses out after the lushness and dew is off the grass. Keep grain in closed bins and the door to the feed room closed.

Give horses unlimited access to fresh, clean water, except immediately after exercise, when the amount should be regulated.

Make changes to routines slowly and progressively.

Pay attention to breed and body types; some are more likely to founder than others. Be particularly careful with horses with thick, cresty necks and with ponies. If you have a horse or pony that has previously foundered, be extra careful to avoid a recurrence.

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What is White Line Disease?

"White Line Disease,"Onychomycosis," "Stall Rot," Hollow Foot," "Wall Thrush, "Yeast Infection," "Seedy Toe" - what is it? All of these names have been used over the years to refer to a fungal infection in the hoof wall.

Definition

White Line Disease, as it is commonly referred to, has been labeled by the late Texas farrier Burney Chapman as "Onychomycosis" - the Latin root, "onyx," meaning nail; "myke" a fungus, and "osis" being condition of.

To define this condition as a "disease" sends most horse owners into a state of panic. A disease and an infection are two different things. An infection, as defined by Tabor's Medical Dictionary, is "A state in which the body, or part of it, is invaded by a pathogenic agent (microorganism or virus) which, under favorable conditions, multiplies and produces effects which are injurious."

The name White Line Disease is also misleading because the white line structure itself (zona lamellatum) is only involved in advanced cases. Basically, this hoof wall condition is caused by one or more fungi acting alone or in combination with bacteria that infiltrate, feed upon and destroy the keratin tissue of the hoof wall. It can occur in one foot or all four and is found among all horse breeds.

Symptoms

Symptoms of hoof wall infection are numerous, often vague, and may differ in each horse. They include:

1. Soft chalky, crumbly horn tissue in the middle wall (stratum medium) which can extend from the ground- bearing surface of the hoof up to the level of the coronary band. The white color results from the lack of pigment in the stratum medium.
2. A hollow-sounding hoof wall upon percussion (tapping) with a hammer.
3. An irregular, thickened white line structure more than 1/8th of an inch in diameter.
4. Weak, chipped, shelly walls that cannot hold a shoe.
5. A large hoof wall cavern visible on x-ray.
6. Wall separation between the hoof wall and sole at the white line.
7. Dish formation along one side of the hoof with a bulge on the opposite side above the infected area.
8. Symptoms of laminitis with coffin bone rotation in advanced stages where the infection has moved from the stratum medium to the stratum internum (inner wall) and involves sensitive lamina tissue.
9. Black finger-like striations in the non-pigmented white layer of the middle wall. Hoof wall separation may not always be detected on x-ray, and separation at the white line can appear as a small area that, when probed, opens into a larger one.

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White Line ~Treatment

The best way to treat white line disease is early detection followed by aggressive treatment. Removal of the affected hoof area, exposure to light and air, and sterilization of the underlying tissue using broad-spectrum bacterio-fungicidal agents is necessary.

Hoof wall resection should be wide enough that the margins of the affected area are free of poor horn tissue and the debridement continued until there is a solid junction between the keratinized wall and the sensitive tissue. If removal is not thorough, viable fungus and bacteria still present can continue to invade new areas or reoccur in newly formed tissue. The defect should be kept as dry as possible and treated with a topical agent three to four times daily, or as directed, for two to three weeks.

Since many of the fungus species produce spores, it is imperative that the topical agent used remains active for a long period of time. It may be possible to keep unkilled organisms from advancing until successive trimmings and growth remove the area with time.

There are numerous topical products available including Fungidye, Thrush-Buster, Save A Hoof, merthiolate, benzoyl peroxide and a homemade mixture of iodine, bleach and formaldehyde. A topical solution called White Lightning can be very effective with recommended use.

Small, affected areas can be treated with resection and topical agents as described, then trimmed and shod normally. If more than a third of the hoof wall is resected, it is helpful to place a heartbar shoe for bony column support, especially if x-rays demonstrate the infection is close to the coffin bone. An eggbar shoe will support the weight of the wall circumferentially.

There is controversy in the equine medical and farrier community as to whether a large, debrided hoof wall defect should be repaired with an acrylic composite, due to the danger of trapping remaining fungi and bacteria in an anaerobic environment, facilitating their reproduction. Acrylic composites can be applied with the addition of an antimicrobial powder, but this will slow the cure rate of the material. This decision should be discussed and agreed upon by the farrier, horseowner and veterinarian, keeping in mind the horse's environment, extent of disease and size of the defect.

Prevention, early detection and aggressive treatment are essential when treating hoof wall disease. Research is currently underway to understand this entity and provide the best treatment options possible

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