It's Bad, It's Very Bad...
- Jul 1, 2004
Midnight has come and gone by the time the Central Kentucky horseman pulls into the stableyard and unloads the young black mare. Both are bone-weary after a 15-hour trip home from the trainer's stable. The man leans on the fence, watching the horse nose around a small paddock lit by a dim light. Tired as he is, he decides to observe the filly just a bit longer before heading to bed.
"That's strange," he thinks. "She keeps drinking a little, then urinating a little. Drinking and urinating." Suddenly, icy dread grips his chest. He races to the house. In a near panic, he knocks books from shelves until he finds the right one, a textbook from a long-ago university animal science class. In minutes, he is back at the trailer, poking through the uneaten alfalfa hay left in the manger. The flashlight shines on something hidden deep in the forage and he gasps. The part he finds exactly matches the photograph in the book--blister beetles.
The mare had ingested one of the most poisonous insects in North America. Just one can kill a full-grown horse within hours. She had been in the trailer with hay infested by several of the bugs for at least 10 hours--ever since a single flake was thrown in at the last minute by a friend who just that day had received a new shipment of alfalfa from Oklahoma.
The man grabs the mare and loads her right back in the trailer, dialing his cell phone as he speeds toward Lexington, Ky., home of Hagyard-Davidson-McGee (HDM) Equine Hospital. Two of only 11 board-certified equine veterinary critical care specialists in the nation work there, and he knows they are his mare's best hope.
Even if HDM's efficient emergency team is able to stabilize her initially, her life will hang in the balance for weeks to come. A critical care specialist is absolutely vital in the effort to keep her alive during recovery and, with luck, give her back some quality of life once the poison has finished ransacking her body.
After alerting the hospital to his imminent arrival, the horseman calls the friend with the new batch of hay, rouses him from sleep, and warns him not to feed any to his horses.
Equine Critical Care
The critical care specialty, first seen in human medicine during World War II and now an integral part of human patient care virtually everywhere (from ambulances and emergency rooms to intensive care units and surgery recovery rooms)--has just recently become better recognized in equine medicine. What people are quite accustomed to seeing at a human hospital--patients hooked up to heart monitors and IVs, with round-the-clock professionals in attendance and a continuous re-evaluation of treatment as the hours go by--is becoming more familiar in equine hospital settings.
Astute veterinarians, owners, and trainers who fervently desire the best possible outcome for the seriously sick horse are quickly realizing the vital importance of critical care to the successful treatment of these animals.
Emergency care and critical care often walk hand in hand, with critical care continuing the journey alone as the patient progresses. For example, an emergency colic surgery might be only the beginning of the road back to health for a seriously ill horse. From the start, and sometimes for weeks afterward, the horse needs to be carefully monitored and treated in a variety of ways to ensure a quality recovery. This is where critical care comes in.
"The ultimate goal in critical care is to keep the patient alive long enough to get well," explains Doug Byars, DVM, Dipl. ACVIM, ACVECC, the senior equine medical internist and hospital director at HDM. Byars is board certified in both veterinary internal medicine and emergency and critical care.
"More specifically, critical care is the maintenance of any animal with a threatening condition in an effort to first keep it alive, and second provide for the best possible quality of life during and after recovery," says Byars.
The clinical applications of critical care to veterinary practice provide for the knowledge and techniques that can save or salvage life, wrote Byars in an essay describing the historical perspective of critical care from human to veterinary medicine for a recent Bluegrass Equine Critical Care and Surgery Symposium. "At the other end of the clinical pendulum, it provides for prognostic assessments that guide decisions for euthanasia or orders for 'do not resuscitate'...Dysfunction of a body system can reflect an early reversible clinical state, whereas failure of two or more systems initiates a prolonged clinical reversal and a mortality prognosis." Simply put, if two systems fail, the death rate is 50-60%, with three systems gone, it's 80%, and four systems means essentially 100% death. And time is often of the essence.
When the little black mare arrived at HDM, she was met by a team of trained staff members in emergency and critical care who knew exactly what to do in this seemingly impossible situation.
An initial assessment was made, including evaluation of her blood work, which showed a very low serum calcium level consistent with intoxication from blister beetles. Oral laxatives were administered in an effort to prevent further absorption of any toxic material remaining in the intestinal tract. In addition, intravenous fluids containing calcium were administered over the next few days, explains Fairfield T. Bain, DVM, Dipl. ACVIM, ACVP, ACVECC, a colleague of Byars at HDM and the clinic's other critical care specialist.
An initial electrocardiogram (EKG) showed an abnormal heart rhythm and the presence of elevated muscle enzymes on the blood work added further support to the concern that the toxin had injured the heart muscle. Additional medications were used to correct the abnormal heart rhythm, and this problem was monitored with an EKG over the next few days until the filly was stable.
"After a few days of being on the 'edge of life,' the filly began to stabilize and finally made the turn toward recovery," recalls Bain.
The little mare was lucky that she resided where she did. The availability of such treatment is, unfortunately, relatively rare. As a specialty in equine veterinary medicine, critical care still is "the new kid on the block."
A Little History
As mentioned, the critical care specialty had its beginnings in human medicine in the mid-20th Century and has since come to encompass virtually all areas of patient care: "The cascades of critical care," according to Byars' essay, were formalized in the early 1970s with the organization of the Society of Critical Care Medicine (www.sccm.org). This discipline is "currently among the leading disciplines within human medicine," states Byars. Small animal veterinary medicine jumped on the bandwagon in the 1980s, with the first credential invitees in 1990.
It was soon afterward that Byars became interested in its application in equine medicine, particularly regarding sick neonatal foals. There are often hundreds treated at HDM out of the thousands of foals born each year in the Bluegrass, the Thoroughbred industry's nursery to the world.
"To better understand the nature of what we do here," explains Byars, "we had 2,200 medicine and critical care cases at the hospital last year. Of those, 450 were sick neonatal foals." Research and improved treatments through critical care allow many more than before to return home to live useful lives.
"People should know that we see everything here, not just Thoroughbreds," offers Byars. "Minis, draft horses, Arabians, Quarter Horses, sport horses, everything; and most can and do benefit from the critical care discipline in many, many instances."
As an internist faced with such challenges at HDM, Byars first sought out human medical symposia on the subject of critical care. What he learned there excited and inspired him. He couldn't wait to spread the word.
"In July of 1995, Doug (Byars) took me with him to a human critical care meeting. I enjoyed every minute of it," says Bain. "I could immediately see the benefits of transferring similar applications from human critical care to animal critical care."
Soon, along with Tom Divers, DVM, Dipl. ACVIM, ACVECC, associate professor of medicine in large animal medicine at Cornell University, the "Three Musketeers" decided that education and board certification in such a discipline was the next important step in promoting its use in the equine veterinary world. In 1996, they prepared (through the appropriate veterinary channels) an examination for large animals, the successful completion of which would allow that veterinarian to achieve board certified status.
Initially, 14 practitioners from around the country were targeted as those most likely to be qualified--based on their background, experience, and credentials--to take the test and thereby benefit from being board certified in the new equine critical care field.
As of this writing, 11 equine practitioners are presently board certified in critical care (although two are not currently practicing). This dedicated group includes Byars and Bain at HDM; Reid Hanson, DVM, Dipl. ACVS, ACVECC, at Auburn University; Divers at Cornell; Gary Magdesian, DVM, Dipl. ACVIM, ACVECC, at the University of California, Davis; Susan Holcombe, VMD, PhD, Dipl. ACVECC, at Michigan State University; Pam Wilkins, DVM, PhD, Dipl. ACVECC, and Barbara Dallap, VMD, Dipl. ACVS, ACVECC, both at the University of Pennsylvania's New Bolton Center; Joanne Hardy, DVM, PhD, Dipl. ACVS, ACVECC, at Texas A&M University; and Janyce Seahorn, DVM, Dipl. ACVA, ACVIM, ACVECC, and Tom Seahorn, DVM, Dipl. ACVECC, both of Equine Veterinary Specialists in Georgetown, Ky.
As a specialty, equine or large animal critical care in the past has not been available as a specific area of study at veterinary schools. Most equine veterinary students might only be exposed to equine critical care as part of a general lecture on emergency medical care. This is changing, however, as veterinarians become more interested in its applications to their patients and within their practices.
States Byars, "The importance of being board certified means that, as a clinician, you are in a position to know a little bit more about the specialty's various aspects than the average practitioner. You know a little more about the kidneys, a little more about the cardiovascular system, a little more about pharmacology, for example, and how they all work together. We learn to be very tuned in to that. Our patient, remember, is a deaf-mute. This forces us to really pay attention to and assemble information when making a diagnosis and deciding on treatment--especially in the critical care situation."
Fortunately, Texas A&M, UC Davis, and University of Pennsylvania offer a critical care specialty and are in the process of formalizing or have formalized residencies in this discipline. Just in time, too, as there is a rapidly growing interest in the field.
HDM is similarly considering offering a critical care residency program as an addition to its existing residency in internal medicine, the only private practice to offer such. HDM has set a standard similar to the Mayo Clinic or John's Hopkins in human medicine.
A Thirst for Knowledge
The popularity of the critical care discipline in equine medicine is growing by leaps and bounds. In 2002, a meeting on critical care was held in San Antonio, Texas, in conjunction with the annual convention of the American Association of Equine Practitioners (AAEP).
"We had between 2,500 and 3,000 veterinarians and support professionals (technicians, nurses, etc.) participate who were vitally interested in some aspect of the specialty," says Byars. "Frankly, while the specialty is of high academic interest to HDM, most practitioners are not really interested in being fully boarded in the specialty. However, they want to know more in order to better treat their patients, and that is wonderful news. There is great potential for its application out on the farms and in the barns where the general practitioner often finds him- or herself.
"Out in the field," he continues, "in all parts of the country, especially among the younger veterinarians, you are seeing them using fluid therapy, catheterization, and other critical care procedures you used to only see in hospital or university settings."
Adds Bain, "Twenty years ago, this was not considered a formal clinical service. As hospitals and universities have grown more sophisticated, practitioners have grown more sophisticated proportionately. They can provide options, state-of-the-art procedures, specialized blood work, and so on that we just didn't provide in the field a few years ago. That stems from a growing knowledge of aspects of critical care."
Byars says that, "20 years ago when a horse needed to be shipped to a hospital or university for referral surgery, he was loaded up and driven as quickly as possible--often for hours--to the surgery. If he had a six-hour trailer ride in the past, for example, he arrived here pretty sick and still had to go through the stress of surgery. Now, he arrives in much better shape and his recovery condition through the critical care stage has a much better chance of a successful outcome. So, our guys in the field are really using these strategies. In addition, owners are coming to expect it--and are really pushing the envelope and demanding more of their practitioners. And that is good for all concerned."
When a seriously sick horse is brought to HDM or a similar hospital, critical care is the first discipline needed--just as in a human hospital.
"Wherever human medicine has gone, and then established some staying power, we have soon followed," says Bain. "Human medicine has the money and the (patient) numbers to break ground, then we can just hit the accelerator and catch up! Critical care is definitely now set to become an integral part of veterinary medicine."
The little black mare from Central Kentucky made a full recovery, went back into training, and is expecting her second foal all because of the quick thinking of her owner, the expertise of the equine veterinary critical care specialist, and a little luck.
"We are not dealing with death here," Byars emphasizes. "We are dealing with life."
CRITICAL CARE IN AN ELOQUENT NUTSHELL
These introductory remarks, reproduced here in part, comprise a stirring summary of critical care and its vital role in the welfare of our beloved friend, the horse. These words were eloquently spoken by David O. Slauson, DVM, PhD, Dipl. ACVP, Distinguished Professor of Comparative Medicine (emeritus) at the University of Tennessee in Knoxville, at the Bluegrass Equine Medicine and Critical Care Symposium held in Lexington, Ky.
"(We are here) to discuss the extraordinary problems of understanding and dealing with the acute equine patient in crisis. Such patients are often intellectually stimulating, clinically challenging, and medically frustrating. They are a blur of biochemistry and physiology gone amuck, sometimes with several organs or organ systems in simultaneous crisis, and they often present within a rather narrow window of opportunity for meaningful therapeutic intervention. As everyone understands all too well, such patients can move rapidly down the clinical time line from asymptomatic to decompensated.
"The emergency and critical care clinician must employ the 'Three Cs' of competence, commitment, and courage within substantial time constraints and sometimes with little information or laboratory data. Time is of the essence; suspected sepsis in a foal may require vigorous intervention prior to proof of its existence. The challenge to act quickly and accurately requires a special ability to rapidly access critical information and the confidence to proceed on skimpy details. This is exciting stuff, with the emergence of new thoughts, actions, needs, priorities, and hierarchies.
"It is reasonable to ponder why a pathologist serves as moderator. I have spent time with Drs. Byars and Bain ostensibly learning about equine neonatal lung disease, but secretly admiring and carefully observing the drama, excitement, and commitment of the ICU in the springtime. I have, in essence, been a pathologist working with a group that does everything it can to interrupt death.
"The intellectual glue that binds us all together, of course, is an unfailing interest in trying to understand disease and its many variable presentations in the acute patient. The critical care clinician must deal with abrupt medical explosions and multiple organ failure, and the pathologist must deal with the aftermath. It is my hope that I might bring a somewhat different 'retrospectoscope' into play that comes from having dealt with far too many critical care patients at their necropsy."--Marian Carpenter
About the Author
Marian Carpenter, a lifelong horsewoman and writer, is executive director of the Texas Equine Veterinary Association. She lives with her family and equine friends near Amarillo, Texas.