Hyperbaric Oxygen Therapy (HBOT) for Horses

by Heather Smith Thomas

Oxygen is one of the most crucial components of the energy production process that fuels our body tissues. It sustains life, and enables injured tissues to heal properly. A procedure for helping many ailments heal has developed from the idea that for optimum healing, more oxygen than normally surrounding and taken in by our bodies can be beneficial.

At normal atmospheric pressure there is a limit to the amount of oxygen carried by red blood cells, and only a very small amount dissolved in the plasma. With increased pressure, oxygen levels in blood and plasma increase, and there is more oxygen delivered to the body tissues. With HBOT, the patient is exposed to a higher level of oxygen in a pressure chamber. Treatments are done at 1.5 to 3 times the pressure of normal atmosphere (usually 2 times normal pressure). Under these conditions, oxygen is physically dissolved in the blood plasma, even in the veins (which normally carry blood depleted of oxygen back to the heart and lungs). The dissolved oxygen is more readily utilized by the body than the oxygen carried by hemoglobin in the red blood cells.

In human medicine, hyperbaric oxygen therapy (HBOT) is being used to speed healing of soft tissue injuries, aid in recovery of stroke victims, and in treating lyme disease, carbon monoxide poisoning, coma, burn injury, circulatory problems, difficult wounds and infections, diabetes, traumatic brain injuries, spider bites, etc. with good results.

A few years ago the first pressure chamber for horses was created by Equinox Technologies (Vancouver, B.C.), and the first available unit was purchased by Doug Herthel, DVM (at Alamo Pintado Equine Medical Center in Olivos, California). Since then, several more units have come into use around the country, including one at Winstar Farms in Lexington, Kentucky. Bill Casner installed that one, and uses it for treating a wide variety of equine ailments.

Winstar was the first farm in Kentucky to have a hyperbaric chamber on farm. "I brought the first unit here in 2001, and everyone who saw that huge chamber thought I was nuts," says Casner. "One reason I believed in this so strongly was the volumes of clinical research about it in the human field, going back 45 years. There have been many studies done on its efficacy in fighting infection, treating wounds and ischemic tissue (deprived of blood). It accelerates healing, diminishes edema, and stimulates the immune system. All of this had already been established in human medicine," he says.

One big use of hyperbarics in horses is in post-operative treatment for colic; HBOT helps restore blood flow to the tissues. "This offers great promise in the veterinary field in managing reperfusion entry. This has been proven clinically with a controlled research project," says Casner.

"Oxygen therapy also stimulates bone healing. You not only get quicker healing, but better healing," he explains. Studies have been done in which fractures were created in rabbits, treating one group with HBOT and a control group without it, sacrificing the rabbits to determine the amount of bone healing. In the rabbits treated with HBOT, the bones healed quicker and stronger.

"This is one of the most powerful tools we can use as an adjunctive form of therapy (and in some cases works well as the primary therapy). One reason it works well in infections is that it increases blood flow to the site, and amount of antibiotic delivery. You also deliver it through the plasma. In addition, HBOT increases effectiveness of the antibiotic. It magnifies the way the antibiotic works against bacteria. It's not just that the amount of antibiotic delivered to the site increases, but it's stronger in its ability to combat the infection. The oxygen also stimulates faster cell turnover, so you stimulate the healing. Oxygen also acts to kill bacteria, because most of the bacteria causing serious infection are anaerobic-- working best in an environment without oxygen," he explains. At pressure, with oxygen at a higher level, it is also detrimental to aerobic bacteria.

"A study done by Fairfield Bain and Nathan Slovis at Hagyard, Davidson and McGee in Lexington evaluated HBOT for treating these foals. In the first study they did, all the foals that came into their clinic with septic joints went through the standard protocols. They used lavage to flush the joints with antibiotics, used systemic antibiotics, etc. There's always been a huge rate of attrition in foals with septicemia; 90 percent of foals that get septic joints have to be put down, and the other 10 percent are worthless. After a long course of treatment, the owner gets a $10,000 vet bill," says Casner.

"So they took all the foals that were hopeless (after 30 to 90 days' treatment)--the ones they couldn't do anything more for, and recommended to be put down--and moved those into the test group. The chamber and treatment time were donated. They continued to use their standard protocols, but combined it with hyperbarics. They had a 60 percent recovery rate, which was fantastic, because these were all foals that were at the point to be put down. One of them sold later at Keeneland; radiographically he was clean. He not only whipped the infection, but his bone grew back." Infection eats the bone away. But with oxygen treatment, the joint healed and the integrity of the bone was regenerated.

If a person can start treating foals with oxygen as soon as they develop infection, the recovery rate is even higher. "We've done that at our farm. If you combine this immediately with the other protocols, in 2 weeks the foal is 100 percent cured and running around the pasture. It's a non-event, more like any other infection. With most common infections, it takes about 2 weeks to get rid of it," he explains.

"We sold a filly a couple years ago that would have been a dead horse, a 100 percent loss (since she was not insured) without hyperbaric treatment. But we initiated this treatment at the onset of her infection. She was a very nice filly, and had no problems after that, and she sold very well," says Casner.

"It's an amazing tool, and the veterinary community is starting to embrace it, but there are some who are so traditional in their forms of treatment that they continue to be very narrow in their vision, even though there are volumes of clinical research in the human field to support this therapy," he says.

"Here at our farm we've used it to advantage in many ways, including treatment for mares we haven't been able to get in foal. We treated 4 out of 5 mares one year that had been bred on multiple covers. We finally put them in the chamber and they got in foal the next time. We don't entirely understand why it worked, but suspect there may have been a bacteria involved--that we were able to eliminate with the oxygen treatment," says Casner. "We probably also enhanced the integrity of the uterine lining, making it more receptive. Maybe the oxygen acted as an extender."

Other successes are noteworthy. "We used oxygen therapy on the stallion Kris S a couple years ago. Dr. Herthel wrote an article 3 years ago describing how he'd treated geriatric stallions for laminitis and noticed some interesting side effects, including an increase in fertility. This caught my interest; there seems to be a logical basis for it. One of the things hyperbarics does is create revascularation of areas with diminished circulation. You get much better blood flow to the extremities, for instance, reestablishing integrity of blood vessels, etc." says Casner.

"We decided to treat Kris S in the chamber and got the ok from the syndicate. We started treating him and there was a very dramatic change in him. He'd been navicular the whole time we'd had him here at the farm, and one of the first things we noticed after a couple weeks of HBOT treatments was that he was much more comfortable on his feet and started walking better. He got to where he would lope in his paddock, and strut and bounce! He hadn't done that in years," explains Casner.

"His covers in the breeding shed had declined; he'd gone from being a 4 or 5 jump stallion to a 2 or 3 jump stallion. After his treatments we were able to collect him with a condom; before this, his lack of libido would never have allowed it. So he obviously had an increased libido, and the morphology of his semen was much better. One of our reproductive vets monitored him, and said there was definitely an increase in sperm count and better quality. The overall vigor of the horse changed dramatically," says Casner.

The stallion did very well for awhile, until an unfortunate event in the breeding shed (in which he came off a mare with his neck cocked), injuring his neck. "He'd had some arthritic changes in his neck, and a spur broke loose, and wedged in one of the joints. We tried everything to resolve that, but he was in pain and would always keep his neck cocked. We kept treating him in the chamber a few times, hoping it would help, but it didn't," he says.

"After we stopped his oxygen treatments, I fully expected the horse to go back to being navicular and lame within a few weeks, but he didn't. We ended up having to put him down about 120 days after his neck accident, but in all that time he continued to walk well. The oxygen had actually had a healing effect; it wasn't just a temporary relief of pain. We are just guessing, but we think it probably helped to revascularize those feet. Circulation seems to be one of the major problems in feet," explains Casner.

There is also a chamber at Fossil Creek Veterinary Clinic in Loveland, Colorado. Dr. Wayne McIlwraith and other researchers at nearby Colorado State University have a strong interest in hyperbarics, says Casner. "Before that chamber was installed, McIlwraith treated a young racehorse and stallion prospect that developed an infection, and sent the horse to Kentucky as a last resort to be treated in a hyperbaric chamber, and after 8 or 10 treatments, in combination with antibiotics, they got rid of the infection. The horse survived, and today is standing at stud."

At higher elevations, our bodies (horse or human) are already operating in an oxygen short environment. The air is thinner than at sea level. "So it's a bigger challenge to heal infections. The bacteria that thrive without oxygen have the advantage at high altitudes, and healing also does not happen as fast because the oxygen level in tissues is lower," he says. This is another reason that the folks at Colorado State University are so interested in the oxygen chambers.

"Fairfield Bain at Hagyard, Davidson and McGee in Lexington says hyperbaric oxygen therapy is the most significant veterinary tool since the ultrasound machine. Dr. Bain recently worked with a racehorse with a lung abscess--that was treated with conventional methods for 30 to 40 days and continuing to worsen. The trainer then requested that hyperbarics be combined with the traditional treatment. Dr. Bain was then able to heal the horse in a very short time. HBOT has been very effective in treating human lung abscesses, and works equally well in horses," says Casner. As horse owners and trainers become more educated about it, more clients will request this type of treatment.

Casner suspects that within a few years there will be many more veterinary clinics and breeding farms that utilize the chambers. Presently Hub and Kirsten Johnson have a chamber at their Kesmarc farm near Lexington, where they run one of the most progressive rehab centers in the country, says Casner. "It has a swimming pool, aquatread, indoor jogging track, and the hyperbaric chamber. They are very progressive in rehab, and Hub has hundreds of success stories with the chamber--because he's gotten so many referral cases of horses with problems."

One of the spectacular cases was a draft horse stallion that had been savaged by another stallion, with a piece torn out of his neck that was the size of a garbage can lid, says Casner. "The horse was dying. He'd quit eating, and given up. The owner, a veterinarian, brought him down here to Hub Johnson. After the second treatment in the chamber, the horse started eating again and turned a corner. The wound stabilized and started healing rapidly."

"The horse started feeling good again, and the owner took him back home, and continued sending photos of the healing progress. The amazing thing is that even though all the hide was taken off that large area, it has now healed and is actually growing hair back. When you see cases like this, you can understand why I've become so passionate about this treatment, and become so frustrated with some of the vets who continue to ignore the magnitude of information out there about this," says Casner.

"At his rehab center, infections are what gets so many of our horses, and the oxygen therapy is nothing short of miraculous in treating those. The question a lot of people have is that if this is so good, why aren't veterinarians doing it? Many vets have never heard of HBOT. Until recently, there have been no equine chambers. This treatment was not taught in vet school, and they have not had a hyperbaric oxygen chamber available to them; most have no experience with it," says Casner. But this will eventually change, he says.

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This article is from 2005, however not dated.

Information copied for educational purposes for clients, business associates and students only in January, 2006.