Unfortunately, regardless of our best intentions, horses get themselves into trouble at rides. The purpose of this article is to help familiarize you with some of the most common problems requiring veterinary treatments, what those treatments might entail, and what will be the expected outcomes from those treatments. Please keep in mind that different veterinarians will have arrived at different treatment protocols based on their own past experiences. Since each of these conditions could have an entire article written about them, this article will be rather brief in some of its descriptions. Any questions you might have on further understanding these conditions should be addressed to a veterinarian familiar with treating endurance horses.

Another reality of owning a horse is that they cost money. Depending on the condition and its severity, treatment costs can run very high. To better prepare yourself to meet these costs it is recommended that you speak with your own veterinarian to see what he or she would charge for the treatments listed in this article. Be aware that costs will vary between different regions of the country and even between veterinarians.

Exhausted horse syndrome

The first condition I'd like to address is what is referred to as exhausted horse syndrome. This happens when a horse has used up all of its energy and reserves during a ride.

One of the main problems with this condition is dehydration. Because this occurs as a result of sweating, several electrolyte imbalances will need to be corrected. These would be sodium, potassium, calcium, magnesium, and chloride. In mild cases, where the horse is drinking adequately, these can be fixed with oral electrolytes. In more severe cases, fluids and electrolytes may be delivered through a nasogastric tube. In other circumstances, these problems will need to be corrected with the use of intravenous treatment.

Dehydration can be severe and it is not uncommon to require anywhere from 30 to 100 liters to correct. Specific types of fluids used will vary, but ideally will be isotonic or neutral in basis. Again, depending on the type of fluids used, the treatment veterinarian may need to add supplemental calcium and potassium to correct the losses. Since the horse is in need of energy, it will be important to have dextrose in the fluids. This will be utilized in the horse as glucose.

Rhabdomyolysis (tying up)

The second condition I'd like to cover is rhabdomyolysis, also more commonly known as tying up. Tied-up horses develop pain and stiffness in the lower back, gluteals and muscles of the thigh region. However, it may originate as an isolated cramp in a single muscle area.

Because of the breakdown/necrosis of muscle tissue that occurs with this condition, myoglobin is excreted in the urine (this is the reason for the coffee-colored urine). This product can be very damaging because of its ability to overwhelm the kidney's ability to filter it out and thereby restricting blood flow (and oxygen) to the kidney. It is for this reason that we try to get the horse well hydrated so as to dilute the effects of the myoglobin on the kidneys.

To try to decrease the amount of muscle damage that occurs, horses with this condition should be moved as little as possible. Do not try to walk a horse out of a tie-up.

The same type and amount of fluids used to treat an exhausted horse can be used to treat a tie-up. A prominent addition to the treatment for rhabdomyolysis is dimethyl sulfoxide (DMSO). DMSO has several positive actions for this condition. First, it is a potent diuretic affecting blood flow within the kidney. It also can act as an anti-inflammatory protecting against endotoxins.

Since horses experiencing tying up are often in pain, several different medications can be used to relieve them. Flunixin meglumine (Banamine) can be used at half-dose levels, but extreme caution must be considered because of the toxic effects that it can have on the kidneys. Phenylbutazone ("bute") is another such product; however, care must also be used in giving this to a horse that is still dehydrated. Owners who stock their own supply of these medications should consult with the ride vet before using it on their horse.

Xylazine and Detomidine can act not only as pain relievers, but will also help sedate the horse and relax the muscle tension that occurs with this condition. Acepromazine is another sedative that may be used in low dosages but, because of its potent vasodilatory effect, it is not suited in all cases. Some veterinarians will also use Dantrolene as a muscle relaxant. It is always important to try to keep the affected areas warm (such as by blanketing) to promote blood flow, thus reducing the amount of muscle damage.

Choke

A third condition that occurs occasionally is choke. Basically, choke occurs when food or other materials get wadded up and stuck in the esophagus. As the horse coughs to try to relieve the obstruction, saliva and feed material can often be found coming out of the nostrils. One of the real dangers with a choke is having some of the feed material inhaled down into the lungs. This can result in what is called aspiration pneumonia. For this reason, horses are put on antibiotics following a choking episode.

The choke itself can often be relieved solely with medical treatment. Tranquilizers, such as Acepromazine, are given to cause the horse to drop its head so as to minimize the risk of aspiration pneumonia and to relieve its anxiety. Oxytocin is administered for its effect on striated muscle to help expel the obstruction. Due to the variation in muscle type, Oxytocin is not as effective on choke that occur from obstructions deep within the esophagus.

At other times, it will be necessary to manually relieve the choke. This is done by passing a nasogastric tube to the site of the obstruction and repeatedly flushing and siphoning water to break up the choke.

Another danger that can occur following an episode of choke is the formation of a stricture or "scar" at the site of the obstruction which results in a narrowing of the esophageal space. This can lead to repeated choking. A follow-up endoscopic exam can assess if damage has occurred.

Lacerations The last problem I want to touch on are lacerations and other penetrating injuries. It's probably self-evident that a horse with a long deep cut will require suturing. However, what if it occurs on the eye or at a joint? In each case it must be determines how serious the injury is. With the eye, this involves applying a nonirritating stain to determine if there is indeed a laceration. If one is found, an antibiotic ointment (one that does not contain steroids) is applied. Atropine may also be used to relax the muscles around the lens and thus reduce pain. The anti-inflammatories discussed earlier can be used as a general pain reliever.

More severe injuries may need to be referred to a clinic for further treatments. With injuries around the joint it is important to determine if the joint capsule is still intact. After thoroughly cleansing the area, the veterinarian will examine the fluid oozing from the wound to see if it feels like joint fluid. It will most likely require some type of manual probing to tell if the joint capsule has been damaged. This type of injury will also need more extensive care than can often be reasonably provided at the ride site.

I've tried to address some of the more severe problems that can commonly occur at rides. I have not touched on colic since that has been thoroughly discussed in the previous two issue of EN. Neither have I mentioned non-metabolic lameness causing injuries. The majority of those will be treated conservatively at the ride site with more in-depth exams and treatments being referred to your own veterinarian. As mentioned at the beginning of this article, if you have any questions on these topics (that were covered rather briefly), please ask your veterinarian.