Treating infections inside the equine hoof always represents a major problem. Horses are mostly affected by large amounts of bacterial contamination, necrotic tissues, fluid coming from the laminae or from the joints inside the hoof capsule.
The way the hoof capsule covers the sensitive structures of the equine digit limits treatment. A great amount of pressure from the edema in turn increases pressure inside the hoof, limiting blood flow through the different plexuses. This prevents blood perfusion and white cells (which kill bacteria) from getting inside the hoof to control the fast growth of bacterial colonies.
Regaining Blood Flow
The most common option is to remove the hoof wall, decompressing the different structures to let the topical solutions do the job. The necrotic fluid and gas are released from the hoof and the necrotic infected tissues encounter antibacterial treatment. But what happens with the third phalanx when this is done?
Problems With Porous Bones
The third phalanx is a very porous bone, which makes it easy for bacteria to penetrate. If the medication a veterinarian is using does not reach the bone tissue, bacteria will grow under the new healthy tissues. Consequently, a chronic infection will appear.
It is very common to see horses suffer from third phalanx rotation and protrusion of the sole. In order to prevent various equine digit tissues from later infections, better treatments need to be developed.
Lack Of Protection
It’s easy to understand how the circumflex artery and the laminae are destroyed. The solar corium and the solar plexus tear off, keeping the blood from carrying more white cells. A large amount of bacterial cells can get into the artery where there is little protection against them. Antibiotics administered intramuscularly or intravenously do not work because there is no blood supply to these tissues following the third-phalanx rotation.
When the marginal border of the third phalanx does not receive any blood, its bone cells start to die. The horse develops bone demineralization, which can limit its athletic life.
Epsom Salt Solution
Some veterinarians recommend cleansing the infected hoof with solutions such as Epsom salts. It’s the cheapest way to treat an infection and clean dead tissues. Hypertonic solutions of salt also drain water from the edema through osmosis, rapidly dehydrating the infected tissues. The hoof starts to look cosmetically better.
However the infection will appear later due to the lack of blood supply and micro fractures of the demineralized bone.
During the acute phase, a horse is reluctant to walk and stand on its feet. The use of anti-inflammatory drugs only creates more problems for the sick animal. The liver, kidneys and blood stream develop more damage due to the pain and stress.
Killing The Infection
The third phalanx needs to be treated with a topical solution. The best way to kill the bacteria and other opportunistic intruders is to get a high concentration of antibiotics into the infected tissues. The best way to accomplish this is for the horse’s veterinarian to use digital intravenous injections of antibiotics.
Once an infection is present, the vet should get a culture and an antibiogram to diagnosis an accurate treatment.
FIGURE 1. Use an inner-tube tourniquet on the cannon bone below the knee to stop the peripheral blood flow toward the inside of the hoof capsule.
FIGURE 2. Prior to catheterization, shave the horse’s fetlock joint and apply iodine soap and an alcohol solution on the area of the digital vein. Desensitize the area with a subcutaneous local anaesthetic.
FIGURE 3. Localize the lateral digital vein on the caudal lateral area of the fetlock joint. It’s easily seen and palpated.
Positioning The Catheter
FIGURE 4. Penetrate the skin with a 21-gauge catheter that is 1 1/2-inches long and position it inside the digital vein. Push the catheter downward inside the vein but insert the needle only 1/4 inch.
FIGURE 5. After the catheter is inside the lumen, take the needle out.
FIGURE 6. Inject a water-base antibiotic until there’s no more blood flowing from inside the vein. Never use an oily base antibiotic.
FIGURE 7. Remove the catheter and apply pressure on the point of insertion to prevent hemorrhage and subsequent inflammation of the surrounding tissues.
The antibiotic works on the tissues for about 15 minutes. Allow the horse to walk. Then remove the inner-tube tourniquet from the cannon bone.This procedure helps treat horses with severe infections in the hoof. Therapeutic shoeing must be performed while treating these horses. Never expect this antibiotic procedure alone to be enough to cure the horse.
In all cases, apply frog support to help the future development of a sound and healthy equine digit.