Common Problems and Their Signs: Part Two
In the April issue, the cover story began our study of common problems that can affect your horse. Those included the oral cavity, eyes, GI system, and respiratory system. The ability to recognize abnormalities depends on a person's knowledge of what is normal; the greater someone's knowledge of normal anatomy, physiology, behavior, and environment of a given animal, the more likely that person is to recognize subtle differences that might be the beginning of a disease process.
In addition to having knowledge of the basics, one must develop strong powers of observation. The inability of the horse to communicate directly is the greatest hurdle we have to overcome as care givers. The purpose of this article is to review the common problems that affect the horse, and to highlight their clinical signs. Most of the diseases mentioned in this article have had entire articles devoted to them, so more information can be obtained from previous editions of The Horse. In this article, problems are grouped by the organ system affected.
(Many sections of this article are adapted from the 128-page book I wrote entitled Understanding Equine First Aid and produced for The Horse Health Care Library. If you wish further information on these and other topics, that book can be obtained through Exclusively Equine at www.exclusivelyequine.com.)
The Musculoskeletal System And Wounds
Acute lameness can be related to something as simple as a foot abscess (actually the most common cause) or as devastating as a fracture. Until the cause is determined, the horse should be moved as little as possible to avoid further trauma should the lameness involve a fracture or tendon injury.
The foot abscess is the single most common cause of acute, severe lameness in the horse. It can affect front or hind feet. If a single foot is warm, and there is sensitivity around the coronary band and/or an increased "pulse" in the foot, the likely cause is a foot abscess. The bottom surface of the foot should be evaluated for any foreign objects, such as a nail. Should a foreign object have created a puncture wound in the foot, do not remove the object until a veterinarian can evaluate it. If the object is protruding significantly, you can tape some small wooden blocks to the foot or cut the object off close to the foot with wire or bolt cutters to prevent it from penetrating farther.
Your veterinarian probably will use X rays to determine what internal structures (if any) were damaged by the foreign object. The location of the puncture can greatly affect the initial treatment plan and the prognosis.
The word "founder" means "to sink to the ground" and refers to what can happen in the aftermath of an episode of laminitis. The coffin bone can become detached from the hoof wall and "sink" toward the ground (or rotate away from the front of the hoof wall). Laminitis causes separation of the non-sensitive hoof wall and the sensitive living tissue that holds it in place and connects it to the coffin bone.
As you know, the suffix "itis" means inflammation, and the disease laminitis is an inflammation of the "laminae" or the anatomical area described above. The disease is most common in the front feet, but occasionally the hind feet or all four feet can be affected. The pony breeds are well known for their increased susceptibility to laminitis, but horses can be affected given the appropriate circumstances.
Laminitis can be related to a number of specific risk factors, with the overeating of grain the best-known cause. In fact, the over-ingestion of carbohydrates, such as grain, can so predictably cause the disease it is the accepted scientific method for creating laminitis for research purposes.
In addition to overeating grain, the sudden ingestion of fresh, lush pasture ("grass founder"), the ingestion of large amounts of cold water ("water founder"), the severe concussion of working on a hard surface ("road founder"), the development of a uterine infection related to a retained placenta, infection with the causative organism of Potomac horse fever, infection with Salmonella, the presence of a pituitary tumor, and a variety of other systemic illnesses are risk factors for the development of laminitis.
Tendonitis (Bowed Tendon)
The hallmarks of inflammation are heat, pain, and swelling. Inflammation indicates an area suspicious of a fracture, but also could be associated with a large degree of soft tissue damage. The flexor tendons and suspensory ligament on the back of the lower leg should be evaluated carefully for enlargement or bowing and other signs of inflammation associated with tendonitis. If the lameness can be isolated to the flexor tendons or suspensory ligament, veterinary consultation should be obtained because working the horse too soon or with an inappropriate exercise program can increase the risk of re-injury. In the time immediately following an injury, a good first move is cold therapy.
If the horse will stand in a tub, a bucket filled with water and ice works well for the application of cold therapy. You also can use hydro-boots or any other commercial cooling product. When all else fails, the cold water hose is a good method of applying cold therapy.
The application of cold can be overdone. The benefit of cold is to decrease inflammation mainly by constricting blood vessels and decreasing circulation to a damaged area. If the area is kept cold for too long, the blood vessels dilate, and the beneficial effects can be lost. The general recommendation is to apply cold for 20-30 minutes, take a break for 60-120 minutes, then reapply the cold. Between cold therapy, the injury can be placed under a thick, well-applied support wrap.
Remember, heat never should be applied to an acute soft tissue injury. That can worsen the degree of tissue damage You should use heat therapy only during the healing phase of an injury (generally at least three days after the injury) and under the advice of your veterinarian.
If a fracture is obvious (the leg is dangling or in an abnormal position relative to the body), the horse should not be moved until the leg is properly splinted or bandaged. A large, thick bandage, generally called a Robert Jones bandage, can be applied the full length of the limb. Typically, four to five full rolls of cotton are applied to the leg (in a pinch a pillow can be used) then covered with four to five rolls of an elastic bandage. If there are any breaks in the skin, they should be cleansed with an iodine scrub (if obviously contaminated) and covered with a sterile pad prior to the application of the Robert Jones bandage.
If splint material is applied, it can be affixed over the Robert Jones bandage with duct tape or other suitable means. A variety of material can serve as a splint, such as PVC pipe, cut off pitchfork handles, or even a wood two-by-four. It is desirable to splint the leg from two right angle sides, e.g., the front and the outside. Remember, the main goal is to stabilize the limb and keep the horse calm until veterinary assistance can be obtained--the sooner the better!
If severe, non-weight-bearing lameness involves a hind limb, the horse should not be moved until he is looked over by a veterinarian, especially if the onset is associated with a fall.
Foot abscesses/puncture wounds are possibilities for the hind limb as well. If there is any chance of a pelvic fracture, movement of the fractured bones can lacerate an artery in the area and can result in the horse bleeding to death.
For severe wounds, the sooner they are noticed and repaired, the better the prognosis functionally and cosmetically. Another aspect of wounds is that they bleed--some significantly more than others.
One of the most important aspects of wound management is the insurance of tetanus protection prior to and after (if booster is necessary) a wound. Vaccination records should be well-documented and easily accessible for all of your horses. Tetanus is a preventable disease in most cases. Satistics indicate that 50% of horses that contract tetanus die from it, therefore, failure to provide protection is, in my opinion, negligent.
Fresh limb wounds that are bleeding profusely will need a pressure bandage. Stay calm; a relatively small, non-life-threatening quantity of blood can look like more than it is. A bandage serves to apply pressure to the hemorrhaging blood vessels and helps promote blood clotting. If a large artery is severed, it can be difficult to apply enough pressure, especially if the laceration is someplace other than the lower limb, but an attempt should be made. The immediate bandage should not be too thick, as that limits the ability to apply enough pressure for bleeding control.
If the laceration involves the flexor tendons or suspensory ligament, an effort should be made to provide more significant support and immobilization. A Robert Jones bandage and splinting, as described for fracture support, should be applied to the leg while waiting for veterinary help. This sort of support and immobilization will help prevent further damage to the injured area if the horse attempts to bear weight. The horse should be moved as little as possible until evaluated and treated.
If the wound is older, bleeding might have subsided or substantially slowed, but there could be significant contamination with dirt, debris, and bacteria. With respect to wound repair, there is what is known as the "golden period." This is considered the first six hours after the wound is created. If the wound is appropriately cleaned and repaired during that time, the chances of complication from infection and subsequent repair breakdown are reduced. Therefore, it is important to have wounds evaluated and repaired as soon as possible.
While waiting for repair, cleansing the wound with warm water and an iodine-based surgical scrub can decrease the amount of contamination and potentially reduce the risk of complications. Applying a sterile dressing and support bandage can help, especially if the horse cannot be seen by a veterinarian right away. If the wound is old (has dried-out skin edges or the presence of pus and infection) and has a large degree of swelling and inflammation associated with it, cold hose therapy can be helpful. Cold hydrotherapy can reduce some of the inflammation and aid in the cleanup process until a veterinarian can properly debride the wound.
Another problem horse owners contend with is a reaction or abscess related to a vaccination. A local or whole body reaction to a number of the equine immunization products is a well-known side effect. A common misconception is that these reactions are a result of a "dirty needle" or "poor injection technique." These problems, in reality, usually are muscle tissue reaction at the vaccination site. Look for heat, pain, and swelling at the site within two or three days of vaccination. Some horses demonstrate signs of systemic illness, such as depression, inappetence, and fever. This type of injection reaction might need to be lanced and allowed to drain, but initially heat should be used at the site.
The application of heat can be extremely beneficial when trying to "mature" an abscess or area of infection in an effort to promote resolution or drainage. As with cold therapy, it can be overdone. One of my favorite ways to apply heat is placing a wad of cotton in a closable plastic bag, adding water that is just hot enough to hold in your hand. This can be held on the desired area for 20-30 minutes and repeated several times per day, ringing out and re-heating the cotton as necessary. Electric heating pads should not be used as they can burn the skin if not monitored carefully. The "hot water bottle" is still available in most drug stores and works well. Your veterinarian should be consulted before using anti-inflammatory drugs such as phenylbutazone (Bute) or applying topical anti-inflammatories such as dimethyl sulfoxide (DMSO).
Dehydration can be a significant problem for the performance horse as well as for horses suffering from other disease processes. The assessments for dehydration you can perform on the farm are subjective, but can be valuable. The most common test is the so-called "skin-tent." This is based on the premise that as the skin becomes dehydrated, it loses its elasticity to the extent that when deformed by a pinch, it will return back to normal slower than it should. This test is performed in an area that has some degree of consistent tension on the skin (e.g., the point of the shoulder). Generally, the skin should snap back to normal in one or two seconds. One note--older horses tend to lose the natural elasticity to the skin and can have longer return times than their younger companions. If you know what is normal for your horse, and perform the test consistently, it can be a useful test of hydration status.
You also should note the degree of moistness of the mucous membranes of the mouth. Dry or tacky mucous membranes indicate dehydration. Also, if the eye appears to be sunken into the socket and has lost the luster to the outer surface (the cornea), significant dehydration is probable. Depression and an elevated heart rate are additional, non-specific signs of dehydration.
Endurance and event horses can lose a substantial amount of body water (as well as electrolytes) in their sweat. It has been shown that three-day event horses can lose up to 20 liters (five gallons) during the cross country phase of an event. It is important to make an effort to prevent dehydration from occurring. Performance horses might become mildly to moderately dehydrated prior to exercise. If the horse did not drink well on the trailer and does not like the "new" water at the competition, dehydration could occur before that first drop of sweat.
A severely dehydrated horse should receive medical attention and most likely will require intravenous fluids or the forced administration of water via stomach tube. Many of these horses also have blood electrolyte abnormalities that require correction.
A final word on dehydration. If living in a part of the country where keeping water a liquid during certain times of the year is a problem, extra concern is necessary. If a horse, or any animal, has been inadvertently deprived of water for several days (or an unknown period of time) due to frozen water or pipes, the animal should not be allowed to drink large quantities of water at one time. It is well-documented that the rapid and large consumption of water following a period of water deprivation can cause serious brain disease. Water should be offered in small quantities (one liter per horse) once every few hours until the animal has had its fill, then gradually allowed access to free-choice water.
I attempted to "hit the highlights" of many of the more common problems our equine friends encounter. Remember, the only way we have of determining illness in our horses is by observing the clinical signs manifested by these problems. It is important to learn the normal physiologic parameters and behavior of your horse and to develop powers of observation. The earlier we suspect something is wrong, the sooner treatment can begin. In many cases, early detection means the difference between life and death.
About the Author
Michael A. Ball, DVM, completed an internship in medicine and surgery and an internship in anesthesia at the University of Georgia in 1994, a residency in internal medicine, and graduate work in pharmacology at Cornell University in 1997, and was on staff at Cornell before starting Early Winter Equine Medicine & Surgery located in Ithaca, N.Y. He is also an FEI veterinarian and works internationally with the United States Equestrian Team.
Ball authored Understanding The Equine Eye, Understanding Basic Horse Care, and Understanding Equine First Aid, published by Eclipse Press and available at www.exclusivelyequine.com or by calling 800/582-5604.
POLL: Managing Working Horses