The Power of Hydrotherapy

There's something almost spiritual about the healing properties of water. Humans have used this life-giving liquid to encourage healing, in themselves and in their horses, since the dawn of time. Water cleanses (in fact, several of the world's religions have endowed it with symbolic purifying properties). It soothes, it draws away inflammation and infection, and it does so in the most natural way. It's simplicity itself, borne of a simple molecule composed of two hydrogen atoms bound to an oxygen atom.

Hydrotherapy in use
LORI RICE PHOTO

Equine swimming pools are a time-honored way of improving a horse's fitness level.

Even with all of the advances in veterinary medicine we've seen over the past century, there's still no substitute for simple, soothing water. For many equine injuries, hydrotherapy (applying water to encourage healing) is just what the doctor ordered--and can help the healing along better, and more cheaply, than many of our chemically advanced lotions and potions or electronic gadgets.

"Hydrotherapy," says Sigle Magner-Skeries, a certified equine massage therapist and founder of Treetops, an equine rehabilitative center in Alliston, Ontario, "is just a fancy term for very simple stuff we apply in our barns every day. You don't need to be an expert to use it."

Let's take a fresh look at what hydrotherapy can accomplish.

Running Water

So basic, yet so effective: that's what hosing an injury is. When you aim running water from a hose at (or just above) a new injury site, you sweep away dirt and debris in the gentlest way. Provided the water is cold, you also encourage the inflammatory process to slow down, reducing the amount of swelling and pain your horse is experiencing. Cold hosing can be one of the most useful ways of reducing inflammation. Because the water is flowing, it doesn't tend to warm up in reaction to equine body heat (and lose its effectiveness), and because the hose is mobile, you can use it almost anywhere on your horse's body. Cold hosing requires no special skills to apply, other than a modicum of patience, and because it can be done almost anywhere, anytime, it should be considered the first line of defense when a new injury--a kick, a cut, a bump, a bruise--occurs.

To understand how and why cold hosing works, you need to understand a little bit about the inflammatory process. Here's how the "panic button" works.

When cells are injured (from a cut or tear through the tissues, or by concussive trauma, which causes bruising), they release enzymes and proteins. These summon infection-fighting white blood cells, or lymphocytes, from other areas in the body and cause blood vessel walls in the vicinity of the injury to dilate and become more porous. The lymphocytes rally to the cause, passing through the porous membranes and entering the injured tissues to begin the infection-fighting process. Extra fluids, carrying oxygen and proteins for tissue repair, also pool nearby. The tissue damage also triggers the secretion of prostaglandins, hormones which are responsible for much of the pain the horse feels.

The three main symptoms of inflammation--pain, heat, and swelling--occur in varying degrees, depending on the site, nature, and severity of the problem. All three symptoms are natural and functional responses to an injury. Pain alerts the horse to the problem and warns him not to use the affected area. Heat is an indication of the increased blood flow to the injury site, and swelling (or edema) helps immobilize the area.

When inflammation rages out of control, however, it actually can hinder the healing. Excess edema can create a "swamplike" environment, which makes it difficult for healthy cells in the vicinity of the injury to get enough oxygen from the blood (in essence, the cells drown). The result is secondary tissue damage called hypoxic injury, which can compound the problem. In addition, blood vessels in the area are put under increasing pressure by the fluid build-up, so the flow of blood and lymph tends to stall. Often, edema can interfere with an accurate diagnosis of the underlying injury--so your first goal is to reduce the swelling and discomfort.

The safest way to break the destructive cycle of secondary cell injury and excess edema is to use the horse's natural mechanism--his circulatory system--to sweep away excess fluids that have collected in the tissues. (While anti-inflammatory agents like bute can reduce swelling and heat, they also can mask pain and confuse the diagnostic picture.) There are two ways of encouraging this--applying heat, and applying cold. Heat should never be applied to an acute injury.

Cold Water Therapy

The application of cold hydrotherapy to the skin surface triggers three reactions. It works at a cellular level, restraining the metabolic response of the cells, so that they can better survive the not-so-beneficial side-effects of healing. In essence, it puts them into a state of hibernation, so that the cells need less oxygen to function, and thereby suffer less hypoxic injury. Cold therapy also decreases the permeability of the blood vessel walls, limiting the flow of enzymes that sound the alarm and thus reducing the amount of fluid that accumulates in the area. As anyone who has held an ice pack to a black eye knows, the cold also numbs the area to a certain degree, acting as a topical analgesic.

Magner-Skeries calls cold hosing one of the simplest forms of hydrotherapy, "but one of the most beneficial, too. The horse gets a mini-massaging action from the water flow, which can help stimulate circulation and tissue regeneration."

Most veterinarians recommend that a new injury be cold-hosed for about 20 minutes at a time, as many times a day as you can manage. Shorter periods aren't as beneficial, as they don't give the blood vessels enough time to react fully.

Another approach to cold therapy is the application of ice packs, which can be pressed or wrapped on the affected area. Ice provides a really concentrated cold response, which can stimulate faster results. The only disadvantage is that because ice packs are stationary, the horse's body will tend to heat them up, rendering them ineffective after a few minutes. Therefore, you'll need to monitor the packs and replace them as they thaw. Ice is particularly effective in reducing swelling on a new injury, and it works best when applied to moist skin (dry skin and hair are very effective insulators against cold). Apply ice for 15 to 20 minutes, every two hours, for best effect. You can damage the tissues if you apply ice for longer than that. Here is another caution: if your horse has an open wound, apply cold only until the swelling subsides, because it can retard the formation of tissue to close the wound. If he has a "closed" injury (such as a hematoma or bruise), however, it's safe to continue applying cold until all of the heat has subsided. If you have any doubts or questions, ask your veterinarian.

One of the best things about cold is that, unlike some other approaches such as drug therapy, it will not override the beneficial effects of the healing process. Corticosteroids, for example, can reduce heat and inflammation, but they do it by shutting down the whole healing process, while cold therapy merely controls and regulates it.

According to Mario Lopez, BVSc, a Toronto-area veterinarian whose practice includes both sport horses and Thoroughbred and Standardbred racehorses, the best time to use cold therapy is when the injury is new, hot, and painful, usually in the first 24 to 48 hours. This is the period when inflammation is most likely to get out of hand. Magner-Skeries agrees: "With a new injury, I recommend that you get some cold water flowing on it right away, even before you call your vet out. Your horse will get the most benefit out of it if it's immediate." At Treetops, she often uses whirlpool boots or tubs to treat new injuries. The jacuzzi action helps gently massage the tissues and further stimulates the healing process.

Hot Water Therapy

As the heat and pain subside (which can take from a day to a week or more, depending on the nature and severity of the injury), slowing the circulation to the site becomes less desirable. You have reached phase two in the healing process, when you want to encourage circulation as much as possible to maximize the healing effect. To do this, you must switch to applying heat--which also can be done with hydrotherapy, providing you have the luxury of a hot-water heater in your barn.

When heat is applied to the skin surface, it causes blood vessels to dilate, increasing blood flow to the site. As capillaries (the tiniest blood vessels that surround the cells) open up, they allow more oxygen and nutrients to reach the injured cells, supporting the growth of new, healthy tissue. The increased blood flow also helps sweep excess fluid out of the area, along with the dead cells and other debris that are the residue of the healing process. The application of heat helps ensure that the horse's body does a thorough job of healing.

A hosing schedule similar to that you used when applying cold water is appropriate. Be sure you are not going to scald your long-suffering patient. You should be able to tolerate immersing your hand in the water (aim for about 130 to 140° F).

Another variation is the hot compress, a soft cloth (old terry towels or flannels are good, a bandage quilt also will work) soaked in warm water and pressed on the injured area. This method works on areas inaccessible to buckets, and it is particularly good for sore backs. Whirlpool boots can as easily be filled with warm water as cold. If you have access to the boots, whirlpool the injury for one to two hours at a time, two to three times a day. In general, moist heat, such as a compress provides, penetrates into tissues better than dry heat, such as you'd get from a heating pad or heat lamps.

Although it might be soothing initially to surface nerves, heat should never be applied when an injury is still warm to the touch. Inflammation is still present if there is heat, and applying more could send inflammation spiraling out of control, perpetuating cell destruction and pain. In addition, any infection present in a fresh injury will be encouraged to spread by the increased circulation that heat therapy triggers. Heat does nothing to treat hard-tissue problems, although a hot compress might ease surrounding tissue stiffness and make an arthritic campaigner feel less creaky for a while. But heat can be used to draw infection out of a cold injury, such as an abscess in the foot, by encouraging the infection to come to the surface and drain.

As a general rule of thumb, remember this: if the injury feels hot, apply cold. If it feels cold, apply hot.

Running Hot And Cold

For chronic fluid congestion in the tissues, sometimes seen in older injuries that just don't seem to be resolving completely, Lopez suggests alternating hot and cold therapies. This approach seems to "open up" the body processes and shut them down again, stimulating the best beneficial effects of both. Cold hose the area for 20 minutes, then follow with the application of a warm compress. Repeat the process two or three times over the course of a day.

Magner-Skeries uses a variation on this idea to help her clients' horses improve their overall circulation. She calls it a "contrast bath" and compares it to the practice of many vigorous Scandinavian peoples (and even the ancient Romans) of jumping in a cool bath, then steaming in a sauna. To give your horse a contrast bath, you'll need a faucet that allows you to adjust the water temperature (many people install a bathtub-type fixture in their wash stalls for this purpose). After your horse has exercised, rinse him down first by lightly spritzing him with cool water--a little cooler than he'd normally like--for about a minute. The aim, says Magner-Skeries, is not to wash him right down, but just to get him a little damp. Then change the water temperature to slightly warmer than you'd normally use, and repeat the quick spritz. Dial back to cool, then to warm again, making each interval slightly more extreme in temperature--a little colder than last time, then a little hotter. (Gradually, your horse will become wet enough so that you can scrape off sweat and dust from his workout, just like a regular bath.) If your horse tends to stock up (experience edema and filling in his legs), she suggests finishing up with a round of cold water. If he suffers from stiffness or arthritis, he'll get the most benefit if you finish up with hot water.

"A contrast bath," Magner-Skeries says, "is awesome for activating your horse's internal temperature gauge. It stimulates the tissues, and gets more highly oxygenated blood to those tissues faster because of the dilation and contraction of the blood vessels. My clients can't believe the difference in the overall tone and vitality of their animals after doing this just a few times."

Another hydrotherapy technique used at Treetops is steaming the horse with warm water and Epsom salts (magnesium sulfate), which Magner-Skeries says is particularly therapeutic for horses who tend to tie up, or for any horse who's just finished a strenuous workout (such as a race, endurance ride, or a tough day out foxhunting). When the horse's heart rate and breathing have recovered to a resting rate, you can prepare his Epsom salts bath by pouring five to six cups of Epsom salts (available at your local pharmacy) in a large tub, such as a plastic muck-skip. Fill the tub with hot water and stir to dissolve the salts. Then soak a wool cooler in the solution (you might want to designate one cooler specifically for this purpose, as the Epsom salts tend to stay in the fabric), wring it out, and drape it over the horse in the usual way. Leave it on till it begins to cool, then soak it again (you migth have to add some more hot water) and replace it on the horse. Repeat for a total of three applications.

"This feels for the horse like a long, hot soak in a tub feels for us at the end of the day," says Magner-Skeries. "A horse who receives this treatment will often be less stiff the next day. It also soothes bruises and bangs so that there'll be less swelling."

One important note: Magner-Skeries says that the documentation on the effects of these kinds of hydrotherapies on horses is sketchy. "As a therapist, I've had to borrow a lot of these rehabilitative techniques from human physiotherapy or sports therapy. Their use is well-documented in human athletes, but few studies have been done specifically on horses to this point." Fortunately, hydrotherapy has an extremely wide margin of safety, and Magner-Skeries says, "You can't really go wrong using water." However, you should consult with your veterinarian before you try any new treatment.

Immersion Therapy

Let's take hydrotherapy one step further and talk about dunking the whole horse. Equine swimming pools are a time-honored way of improving a horse's fitness level and allowing him to rehabilitate from an injury while avoiding any weight-bearing concussive forces on his limbs. Most often used for racehorses (both Thoroughbred and Standardbred), swimming pools also can find a useful place in the routine of high-performance athletes such as three-day event horses and combined driving horses. However, over ground exercise is needed to build and maintain strength in the musculoskeletal tissues that need it most. Also, heart rate is lower during swimming than during overground exercise. Swimming does stress the respiratory system due to pressure on the chest, which is also unnatural for horses.

"What is really great about hydrotherapy in its most extreme form--swimming--is that you can bring a horse who might otherwise not be able to do any conditioning work at all (because of an injury) to almost total fitness," says Magner-Skeries. "If you have a pool, you can challenge your horse's musculoskeletal system and cardiovascular system without concussing the injury. Then by the time he's ready for concussive forces, he already has a baseline of fitness and can go on from there. (Swimming) is great resistance training, even for a sound horse."

She notes, however, that swimming won't take the place of speed work. The main function of swimming is to improve cardiovascular fitness and provide strength training. "Horses who get fit through swimming don't tend to get lean," she says.

Even a few minutes in a swimming pool is a serious workout for most horses; they're not naturally strong swimmers. (In fact, some have to be assisted with an inner tube around their necks!) But most accept the idea of doing a few laps in the pool fairly readily. Having qualified help available can be an important safety consideration, though. Don't attempt to swim a horse by yourself unless you and your horse are both very familiar with the routine.

Not everyone agrees that swimming is a useful therapy for horses. Doug Hannum, of the Hannum Equine Sports Therapy Center in Nottingham, Penn., notes, "Horses are not swimmers. You don't see a horse naturally wade into a pond and go for a swim. When they do swim, they're going against all their training (for a round top-line), because they get completely inverted, with a high head and a hollow back. It goes against their natural biomechanics.

"I've seen horses develop very sore backs from a regular swimming routine, and I've also seen them develop stifle problems from the motion of kicking down," he says. Furthermore, he suggests that concussion on the limbs is a natural and essential part of the healing process, and shouldn't be avoided.

The solution could be a hybrid machine that combines the therapeutic effects of warm water, massage jets, and a treadmill, which Hannum markets under the name Hydraciser. In essence, it's an equine jacuzzi with a treadmill bottom. (There are several companies that manufacture underwater treadmills. Comparisons should be made to see which model offers you the options you need for your animals.)

"In a Hydraciser tank," he explains, "you get concussion, but it's reduced because the horse is 35-45% buoyant from the water jets. The same idea is used in hydrotherapy for humans recovering from injuries. The water is 98° Fahrenheit, and there are 18 powerful jets, so it's very soothing, and you tend to be able to get the horse to flex stiff joints or areas of scar tissue well in there."

The Hydraciser's heavy-duty fiberglass tank is approximately 15 feet long and five feet wide, and can accommodate even a large, long-striding warmblood. It fills with water in approximately two minutes, and drains in less than one. Most horses accept the confines of the Hydraciser fairly readily, Hannum says, particularly racehorses (who are accustomed to starting gates) and horses which have been imported from Europe and have thus experienced an airline "crate." He generally takes about three days to accustom a horse to the Hydraciser before filling the tank with water and gradually starting the workout routine.

There are several advantages to using an underwater treadmill unit. Hannum finds that horses which need hand-walking as part of their rehabilitative routine often can be walked more safely in the confined environment of the tank than they could down a lane. Furthermore, recovering horses tend not to lose muscle tone when they exercise against the current. "It's a tremendous workout," he says.

Although horses usually remain at a walk with an underwater treadmill, the speed at which these units operate is variable, so the cardiovascular system can be progressively challenged (useful for the injured horse which is trying to maintain his fitness level, and for the sound horse which is in a general conditioning program).

Underwater treadmill workouts are particularly good for horses suffering from tendon and joint injuries, and those recovering from orthopedic surgery, says Hannum. The activity of the treadmill belt creates turbulence in the water, which results in an underwater massage effect on the tissues, encouraging increased circulation.

Hannum also finds that the underwater treadmills can be therapeutic for horses with sore backs (even though the back of the horse is not immersed--the water level comes to about midway on the barrel), because the motion of the treadmill helps build muscle strength in the lumbosacral area, and because the horse is working in a normal frame, rather than an inverted one.

He starts most horses with five-minute sessions--like swimming, this is high-intensity exercise. The fittest three-day event horses, Hannum says, might work up to sessions of about 15 to 18 minutes, during which the speed of the treadmill is varied several times to create an interval training-type workout. Hydracisers played a part in the fitness routines of a number of horses which competed in the 1999 Rolex Kentucky Three-Day Event in Lexington, Ky., he said.

Unfortunately, underwater treadmills don't come cheap. The cost of installation of one of Hannum's units is about $85,000. Currently, there are a few dozen Hydracisers across the United States, and demand is increasing. You might be able to take your horse to an equine therapy center to have him work in a tank with an underwater treadmill. Hannum's base in Pennsylvania has a Hydraciser, as does the Red Bank Equine Sports Therapy Center in Camden, S. C.

That's hydrotherapy, from the simple application to the most complex. Any way you look at it, water is a life-affirming force--and a valuable ally in your efforts to keep your horse at the pinnacle of health.

About the Author

Karen Briggs

Karen Briggs is the author of six books, including the recently updated Understanding Equine Nutrition as well as Understanding The Pony, both published by Eclipse Press. She's written a few thousand articles on subjects ranging from guttural pouch infections to how to compost your manure. She is also a Canadian certified riding coach, an equine nutritionist, and works in media relations for the harness racing industry. She lives with her band of off-the-track Thoroughbreds on a farm near Guelph, Ontario, and dabbles in eventing.

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