Rood & Riddle Spring 2018 Newsletter

News from Your Equine Health Care Provider | Vol. 3 |Spring 2018

Dr. Deborah Spike-Pierce Named CEO IN THIS ISSUE EQUINE HEALTH

Dr. Lairie Metcalfe

- Some Thoughts on the Care of Newborn Foalls

Dr. Charlie Scoggin

-Discussion of Equine Reproduction

Dr. Scott Hopper

-Biologically Derived Therapies for Tendon and Ligament Injuries

Dr. Larry Bramlage

-Racehorse Skeletons are Made Not Born!

-’Price to Pay’ for Bisphosphonate Use is Delayed Healing

Dr. J. Brett Woodie -Tie-Back Surgeries

Newest Shareholder Dr. Katherine Garrett Rood & Riddle News

After having been at the helm of RREH since its inception, Dr. Bill Rood is handing over the reins of Rood & Riddle to Dr. Deborah Spike-Pierce.

On January 1st, Dr. Spike-Pierce started a new era at the hospital. Being raised in Michigan, Dr. Spike-Pierce grew up working with Standardbreds and knew at a very young age that she wanted to be a veterinarian. Following her heart she graduated from Michigan State University Veterinary School in 1993 after which she spent a year practicing in Michigan. She then embarked on her life changing journey to Lexington and Rood & Riddle where she did a yearlong internship staying on afterwards as an assistant to Dr. Larry Bramlage. Three years later she started her ambulatory practice, focusing on juvenile Thoroughbreds that were to be sold or raced.

Dr. Spike-Pierce has been very involved thoroughout the years in many veterinary associations. She has held positions as KAEP and KVMA Presidents and is also very active in the American Association of Equine Practitioners (AAEP) where she was recently installed as a member of their board of directors.

Since stepping into the role as CEO Dr. Spike-Pierce has eliminated her primary farm work and spend her days primarily in the office. She still plans on reading a few radiographs as her passion for horses won’t change. In order to fulfill her horse fix she will be spending more time at her farm on nights and weekends.

When asked about moving into her new position, Dr. SpikePierce says “I am excited about taking on the challenge of becoming CEO of this amazing hospital. I look forward to listening to and getting to know every employee. When I came to Rood & Riddle twenty three years ago it was much smaller, but has always been an incredible place to work. My goal is to continue the culture of excellence while enjoying the camaraderie of colleagues and most importantly serving the clients and the horses that give us the opportunity to do what we love.”

Dr. Spike-Pierce has large shoes to fill but will undoubtedly continue the legacy of excellence during her time as CEO!

www.roodandriddle.com

Some Thoughts on the Care of Newborn Foals

by Dr. Laurie Metcalfe

Ambulatory Practitioner at Rood & Riddle

Laurie Metcalfe, DVM “Neonatal care may be required sooner and be more extensive for higher risk foals such as those associated with dystocia (obstructed labor), premature placental separation (red bag), placentitis, prematurity, meconium staining (fetal diarrhea), failure of passive transfer, and those foals who have not stood and nursed by 3-4 hours of age.”

“Neonatal Maladjustment Syndrome (NMS) is more obviously associated with an adverse event at time of foaling, but is also observed in many foals that have not had an obvious periparturient (around the time of foaling) issue.”

“Treatment of NMS foals is largely supportive and will depend on how severely the foal is affected. Many will require extensive nursing care, some of which can be performed at the farm, but more extensive critical care may require referral to a clinic for continuous monitoring.”

Excerpt from

Merriam-Webster.com defines NEONATE as : a newborn child or mammal. The “Neonatal Period” is the time when the newborn undergoes a physiological adjustment from the uterine environment to extrauterine life. In humans this is considered from birth to one month, however in the more precocious equine, we generally consider this to be the first 7 days of postnatal life. Therefore when considering “neonatal care” we are referring to the routine preventative care and initial assessment of the newborn foal within the first 24 hours of life as well as any further follow up and treatment warranted based on physical exam and basic bloodwork.

All foals should be examined by a veterinary professional as there are many problems that begin with very subtle discrepancies that an owner may not become aware of until disease is advanced. Neonatal foals can deteriorate rapidly, so early detection and treatment is essential for the best outcome. Neonatal care may be required sooner and be more extensive for higher risk foals such as those associated with dystocia (obstructed labor), premature placental separation (red bag), placentitis, prematurity, meconium staining (fetal diarrhea), failure of passive transfer, and those foals who have not stood and nursed by 3-4 hours of age.

Neonatal Maladjustment Syndrome (“Dummy Foal Syndrome”) is not necessarily a disease per se but a term used to describe newborn foals that exhibit behavioral and/or neurologic abnormalities resulting from a hypoxic insult (inadequate oxygen supply). Clinical presentation varies widely, but signs can be mild, including loss of affinity for mare, poor suckle reflex, chewing/facial spasms, hypersensitivity to touch, abnormal respiratory patterns, depression and sleepiness. More severe signs include inability to stand, central blindness, stupor and seizures. Signs are a result of oxygen debt to the brain- these signs may be evident at birth, but may not be observed until foal is 24-48 hours old.

Neonatal Maladjustment Syndrome (NMS) is more obviously associated with an adverse event at time of foaling, such as a dystocia or premature placental separation (“red bag” foaling), but is also observed in many foals that have not had an obvious periparturient (around the time of foaling) issue. There is frequently an unrecognized in utero hypoxia which makes these cases less obvious. Hypoxia can occur secondary to a decreased blood flow to the placenta during pregnancy because of placentitis (inflammation of the placenta) or an issue with the dam’s health. It can also occur shortly after birth, usually resulting from a primary issue with the foal’s health including sepsis (infection), pulmonary (lung) disease or problems associated with prematurity. Although frustrating, often a clear cause goes unidentified.

Treatment of NMS foals is largely supportive and will depend on how severely the foal is affected. Many will require extensive nursing care, some of which can be performed at the farm, but more extensive critical care may require referral to a clinic for continuous monitoring.

In conjunction with Rood & Riddle Equine Hospital, “In Conversation with” is a feature in Secretariat’s World, an online magazine dedicated to the business and lifestyle of legendary thoroughbred horse racing. Visit Secretariat’s World at http://www.secretariatsworld.com/

Some Thoughts on the Care of Newborn Foals

(continued)

Most NMS foals are placed on antibiotics, as they are compromised and prone to infection. In addition, most will receive anti-inflammatories to reduce swelling in the brain, and anti-oxidants (thiamine and Vitamin C) thought to protect cells in the brain and promote healing. Some foals will get intranasal oxygen and intravenous fluids as well to maintain blood pressure and circulation. Foals may need to be fed through a feeding tube if not nursing well, however if gastrointestinal tract is compromised, may require intravenous nutrition. Severe cases will need anti-seizure medication as well; these cases are most commonly referred for best prognosis.

Although there are no magic formulas to prevent NMS, the most significant thing an owner and veterinarian can do is monitor and recognize early any problems occurring during the mare’s pregnancy. In addition, foaling should ideally be attended for rapid intervention at the first sign of trouble. Any foal should always be examined by a veterinary professional sooner than later if in doubt. It is thought that about 80% of these foals survive and if recognized early and treated appropriately, a much higher number than previously reported as treatment options continue to improve.

As the Thoroughbred industry as well as other breed industries become more extensive, and more investment is put into the breeding of these horses, the value of the result (the foal) has increased as well. Eleven long months have been put into supporting and monitoring the dam, and ideally we give the foal the best possible chance at success. This is achieved by working closely with a veterinary professional and having a new foal exam performed within the first 12-24 hours and submitting bloodwork for white blood cell count (to ensure no infection) and an IgG. This demonstrates whether or not the foal has received an adequate amount of infection fighting antibodies from the dam’s colostrum, the first milk consumed that is essential for a healthy foal.

Unlike a human baby, who receives all of its antibodies to fight disease from the placenta, the horse acquires it through colostrum only; failure of passive transfer occurs when the foal does not receive adequate colostrum, rendering the newborn foal immunologically naïve and susceptible to infection and even death. The results of a simple blood test, called IgG, which measures the foal’s antibody levels, can allow veterinarians to intervene if necessary (usually a plasma transfusion) and give the foal the best possible prognosis.

Your veterinarian can also identify subtle issues that can quickly escalate into larger problems and intervene before it becomes more severe and subsequently more expensive. If issues do occur, your veterinarian can help define options, outline treatments and give a prognosis. They can guide you in deciding what is practical and affordable, based on the value of foal and the financial situation. I cannot emphasize how important the new foal exam and bloodwork are to the health of the newborn foal.

It is essential that owner/veterinarian work together.

“It is thought that about 80% of these foals survive if recognized early and treated appropriately. This is a much higher number than previously reported, as treatment options continue to improve.”

“failure of passive transfer occurs when the foal does not receive adequate colostrum, rendering the newborn foal immunologically naïve and susceptible to infection and even death. The results of a simple blood test, called IgG, which measures the foal’s antibody levels, can allow veterinarians to intervene if necessary (usually a plasma transfusion) and give the foal the best possible prognosis.”

“I cannot emphasize how important the new foal exam and bloodwork are to the health of the newborn foal. It is essential that owner/ veterinarian work together.”

Dr. Laurie Metcalfe is a shareholder in Rood & Riddle Equine Hospital. She received her DVM from the University of Wisconsin and completed two Rood & Riddle internships programs. She has remained an ambulatory veterinarian with the practice ever since. Dr. Metcalfe concentrates her practice on neonatal medicine, enjoying foals as well as herd health and general medicine. www.roodandriddle.com

DISCUSSION OF EQUINE REPRODUCTION

by Dr. Charlie Scoggin Board Certified Theriogenologist at Rood & Riddle QUESTION: What is Theriogenology and what are the latest challenges seen in the stallion reproductive physiology in the 21st century?

Charlie Scoggin, DVM,

MS, DACT

“As a theriogenologist, there are two great challenges that I commonly encounter with respect to stallion reproductive physiology: reliably predicting fertility; and maintaining adequate libido throughout the course of a breeding season.”

“First and foremost, each stallion is an individual and should be treated as such.

In other words, there is no “recipe” for how to manage a young stallion. For this reason, stallion managers and veterinarians need to take the time to get to know each stallion so that they can tailor their management strategies to best fit that particular stallion’s needs.

Doing so often requires more than one examination or even more than one breeding season to really understand the personality and behavior of a stallion.”

Excerpt from

DR. CHARLIE SCOGGIN: Theriogenology is the study of animal reproduction. In North America, theriogenologists are specialists that have undergone several years of formal and intensive postgraduate training in reproductive anatomy, physiology, pathology and endocrinology of a multitude of species, including mammals, avians and reptiles. As a theriogenologist, there are two great challenges that I commonly encounter with respect to stallion reproductive physiology: reliably predicting fertility; and maintaining adequate libido throughout the course of a breeding season.

QUESTION: How would you define assisted reproductive technologies? And what are the processes/ procedures called into use?

DR. CHARLIE SCOGGIN: Equine assisted reproductive technologies (eART) encompass those techniques that involve manipulative procedures of gametes (e.g., spermatozoa and oocytes) and embryos. These procedures are often employed to generate offspring from mares and stallions that are incapable of either creating or maintaining viable pregnancies. Some procedures, such as semen collection and artificial insemination, have been utilized for decades. Others, such as intracytoplasmic sperm injection (ICSI), are in their relative infancy yet gaining significant momentum in commercial breeding operations. The future of eART is also very bright. On the horizon are commercial embryo biopsying (to diagnose the sex, coat color, susceptibility to disease, performance traits, etc.) a true in vitro fertilization.

It is important to note that the use of eART is not permissible under the current rules of the North American Jockey Club, which is the sole registry of Thoroughbreds in the USA. All Thoroughbred foals must be conceived via live-cover mating and the mare must carry that pregnancy to term.

QUESTION: Is it much more common for Thoroughbred horses to be bred either ‘in-hand’ (that is, the stallion is led by a human), or using ARTs? Could you please tell us more about the process and challenges?

DR. CHARLIE SCOGGIN: As mentioned above, Thoroughbred foals can only be registered if they were conceived via a live-cover (i.e., in-hand) mating and the dam carried the pregnancy to term.

The use of eART is prohibited by the North American Jockey Club and, if I am not mistaken, all Thoroughbred registries throughout the world. Reinforcement matings—which entails collecting the drippings from a stallion as he dismounts a mare and depositing it back into that same mare’s uterus—is permissible, but it is not considered a true eART. QUESTION: What are your thoughts/professional opinion about the possibility of experiencing frustration caused by preventing the animals from fulfilling behavioural needs through natural cover?

DR. CHARLIE SCOGGIN: In my opinion and in general, the form of breeding contributes minimally to a stallion or mare becoming frustrated. However, what can lead to frustration—especially with respect to stallion behavior—is the frequency with which a stallion is bred. If he breeds too little, then he may become overly aggressive or anxious; if he breeds too much, he may become disinterested and shun the breeding process altogether. Fortunately, these issues can be mitigated by proper management and selection of an appropriate mare book size.

Given the artificially limited season (by the studbooks) and the practice of ‘shuttling’ Thoroughbred stallions between Northern and Southern Hemispheres which has the potential to compromise their welfare by subjecting them to the stress of long flights, novel surroundings and unfamiliar pathogens, do stallions have infertility issues, early in their stud career?

First and foremost, each stallion is an individual and should be treated as such. In other words, there is no “recipe” for how to manage a young stallion. For this reason, stallion managers and veterinarians need to take the time to get to know each stallion so that they can tailor their management strategies to best fit that particular stallion’s needs. Doing so often requires more than one examination or even more than one breeding season to really understand the personality and behavior of a stallion.

DISCUSSION OF EQUINE REPRODUCTION

(CONTINUED)

With respect to shuttling stallions, all of the current scientific literature indicates that the shuttling of stallions between the two hemispheres has little to no effect on their fertility. A very recent study tracked the reproductive performance of stallions that shuttled over a 10-year period, and no significant differences were seen in first- and per-cycle pregnancy rates and live-foal rates.

Unfortunately, there have been some publicized mishaps of shuttle stallions becoming sick or even dying, but those cases appear to be the exception and not the rule. The primary factor that can limit a stallion’s ability to shuttle successfully is libido. More studies are necessary to determine how shuttling effects libido both in the short- and long-term.

QUESTION: How does use of a ‘dummy mare’ improve the welfare and extend the fertility of a stallion?

DR. CHARLIE SCOGGIN: The use of a ‘dummy mare’ or ‘phantom’ mount is commonly used in breeds other than Thoroughbreds to collect semen for artificial insemination. The advantage to this method is that it can reduce the risk of injury to both the mare and stallion. Whether it be a kick, untimely move, or savage bite, the potential for injury during live-cover matings most certainly exists. The mare is a potential source of injury, whether it be from a kick, untimely move or falling over. However, frequency and severity of injuries in breeding stallions is not well documented and thus subject to some speculation. In my experience, injuries to stallions as a result of direct trauma from the mare are relatively uncommon. This is due in no small part to the intensity with which both broodmares and stallions are managed, which greatly reduces the risk of serious harm to a stallion during the breeding process.

Regarding how the use of a phantom may extend the breeding career and fertility of a stallion: that is likely a secondary consequence of the ability to collect, process and inseminate mares in a variety of different ways than what live-cover affords. The use of frozen-thawed semen is an excellent example. Cryopreserved spermatozoa can essentially be kept in storage indefinitely. Indeed, there are some stallions that have been subfertile (or even dead) for years, yet the availability and use of their semen remains in circulation because of our ability to preserve and/or manipulate it in a variety of different ways.

QUESTION: Please explain equine ART procedures in greater detail?

DR. CHARLIE SCOGGIN: Artificial insemination (AI) entails the collection and processing of semen that allows for manual deposition of all or a portion of the stallion’s ejaculate into a mare(s) uterus.

Embryo transfer (ET), which is commonly used in many non-Thoroughbred breeds, involves the collection of an embryo from a donor mare’s uterus 6-8 days after ovulation and subsequent transfer of that embryo into a recipient (i.e., surrogate) mare’s uterus. The recipient will then carry the pregnancy to term and raise the foal as if it was her own. In horses, all steps of ET utilize nonsurgical methods of collection and transfer. These particular procedures are used regularly in our practice.

Intracytoplasmic sperm injection (ICSI) involves collection of one or multiple oocytes (i.e., eggs) from a donor mare, followed by injection of a single spermatozoa under microscopic guidance into one of the oocytes. These “fertilized” eggs will be cultured for 6-8 days, after which they will be transferred in a similar manner as described for ET. The commercial use of ICSI has been available for ~10 years in the US and is considered a highly advanced form of ART. Currently, success rates of ICSI are relatively low and operate with poor efficiency. The current literature indicates that the odds of generating a live-foal from ICSI at around 10-25%, which is strikingly low compared to ET, which carries a live-foal rate of ~70-75%. In addition, ICSI is currently the only form of in vitro fertilization (IVF) that researchers have been able to generate pregnancies from. True IVF actually entails coculture of sperm with an egg. Unlike humans or cattle in which IVF is capable of generating viable pregnancies, IVF has proven frustratingly difficult in horses. However, equine researchers are still actively pursuing the use of IVF in horses, and persistence usually pays off.

“A very recent study tracked the reproductive performance of stallions that shuttled over a 10-year period, and no significant differences were seen in firstand per-cycle pregnancy rates and live-foal rates.

The primary factor that can limit a stallion’s ability to shuttle successfully is libido.

More studies are necessary to determine how shuttling effects libido both in the short- and long-term.”

“Embryo transfer (ET), which is commonly used in many non-Thoroughbred breeds, involves the collection of an embryo from a donor mare’s uterus 6-8 days after ovulation and subsequent transfer of that embryo into a recipient (i.e., surrogate) mare’s uterus. The recipient will then carry the pregnancy to term and raise the foal as if it was her own.

In horses, all steps of ET utilize non-surgical methods of collection and transfer.

These particular procedures are used regularly in our practice.”

www.roodandriddle.com

DISCUSSION OF EQUINE REPRODUCTION

(CONTINUED)

QUESTION: What are the areas to be kept in-mind when an owner decides to breed his racehorse for the first time?

“The relatively longgestational length of broodmares naturally increases the chances of an unfortunate event occurring, and—no matter how well cared for mares are—pregnancy wastage (i.e., fetal loss, abortions, stillbirths) will occur in a band of broodmares at a frequency rate of 10% per year. Bottom line: breeding horses is not an “automatic” process that guarantees the birth of a live and healthy foal.”

“Young colts and even mature horses are often discouraged from displaying stallionlike behavior while in training for fear that it can distract them from reaching their full potential.

Suppression of this behavior, while certainly understandable from both a performance and even safety standpoint, can have lasting effects once a stallion transitions into his second career as a breeding animal.”

Excerpt from

DR. CHARLIE SCOGGIN: First and foremost, owner’s need to realize that mares and stallions are biologic entities and not machines. Despite intensive and proper management, per cycle pregnancy rates in horses average 60-70% on most well-managed Thoroughbred farms. So, while the odds are in favor of a mare becoming pregnant after her first breeding, there is also a chance that she may not. Fortunately, the odds are increasingly in their favor by the second mating, and seasonal pregnancy rates on most well-managed farms usually approach 90%.

Along these same lines, it is important for owners to realize that just because a mare becomes pregnant doesn’t necessarily mean she will remain pregnant and produce a live and viable foal. The relatively long-gestational length of broodmares naturally increases the chances of an unfortunate event occurring, and—no matter how well cared for mares are—pregnancy wastage (i.e., fetal loss, abortions, stillbirths) will occur in a band of broodmares at a frequency rate of about 10% per year. Bottom line: breeding horses is not an “automatic” process that guarantees the birth of a live and healthy foal.

QUESTION: What challenges can a first time stallion face?

DR. CHARLIE SCOGGIN: One of the biggest challenges is adjusting to a very different life than what they were accustomed to while in training and active competition. However, stud duty has its own demands, both physically and mentally. As such, new stallions should be given plenty of opportunity to “let down” following retirement from racing. This adjustment period can also be used by the stud grooms to also familiarize themselves with the stallion, allowing them to tailor management strategies to their new addition.

Another challenge is offering reassurance via positive reinforcement for new stallions to express themselves in a natural yet respectful manner. Sometimes this takes a few days of training; other times, it can take weeks if not a whole breeding season to instill in a young stallion to breed with confidence. Young colts and even mature horses are often discouraged from displaying stallionlike behavior while in training for fear that it can distract them from reaching their full potential.

Suppression of this behavior, while certainly understandable from both a performance and even safety standpoint, can have lasting effects once a stallion transitions into his second career as a breeding animal.

Fetal Sexing

Palpation

Collection

Dr. Scoggin attended both graduate and veterinary school at Colorado State University where he obtained an MS in equine reproductive physiology in 2001 and his DVM in 2005. Following his internship he accepted a position as a resident veterinarian at a Thoroughbred breeding farm outside Paris, KY, where he practiced from 2008-2015. He became a Diplomate of the American College of Theriogenologists (animal reproduction) in 2012, and he joined the team at Rood & Riddle in July 2015. Dr. Scoggin’s professional interests include stallion reproductive physiology, problem mares, and assisted reproductive technologies

Biologically Derived Therapies for Tendon and Ligament Injuries

by Dr. Scott Hopper Board Certified Surgeon at Rood & Riddle

T

he use of biologically derived therapies in horses is common in equine practice. The most commonly used biologic products used to treat tendon and ligament injuries are mesenchymal stem cells (MSC), platelet rich plasma (PRP) and bone marrow concentrate aspirate (BMAC).

The other biologics such as autologous conditioned serum (IRAP) and autologous protein solution (Prostride) are derived for use in joints.

Stem cell therapy is commonly used for a variety of tendon and ligament injuries. Bone marrow is the common source for stem cells at this time. A core lesion of a tendon or ligament is the text book case for stem cells. The stem cells are injected via ultrasound guidance directly into the lesion. In many cases the stem cells are used in combination with other treatments or surgery such as tendon splitting, superior check ligament desmotomy or shockwave therapy.

Some lesions are not amenable to intra-lesional injections and treatment is done via regional limb perfusions. Intravenous perfusions have been used most commonly but recent research indicates regional limb perfusions using the median artery in the forelimb without a tourniquet allows better distribution of cells. Horses are typically treated one to three times depending on the severity of the lesion and progress. Research has also shown that the recurrence rate of superficial digital flexor tendonitis is decreased by 50%. The tendon will heal no matter what we do but the quality of healing and the incidence of recurrence will vary significantly based upon the treatment and rehabilitation program chosen.

Platelet rich plasma (PRP) was first described in treating suspensory ligaments in Standardbreds. PRP is made up of platelets and several growth factors that can aid in decreasing inflammation and will promote healing. PRP is commonly used in human medicine also to treat tendon and ligament injuries. In a recent study it was shown the PRP was successful at returning 80% of horses to their previous level of work at 12 months compared to horses that were not treated. Unfortunately, only 60% of the horses were still in work at 24 months compared to 50% of the controls. There are several different PRP products available but they are not all the same. Consult your veterinarian to help chose the best product for you horse. Typically, PRP is significantly less expensive than stem cell therapy.

Bone marrow aspirate (BMAC) was the first biologic therapy used to treat tendon and ligament injuries. A bone marrow sample is easily collected, prepared and injected into a lesion. This treatment is done less frequently today with the development of stem cell therapy and PRP. The use of biologics has significantly improved our success in treating tendon and ligament injuries. The rehabilitation program post treatment is extremely important in the success of these treatments and should not be overlooked.

Bone Marrow Collection

SDF Core Lesion

60 Post Treatment

Scott Hopper, DVM, MS, DACVS

“Stem cell therapy is commonly used for a variety of tendon and ligament injuries.

Research has also shown that the recurrence rate of superficial digital flexor tendonitis is decreased by 50%. The tendon will heal no matter what we do but the quality of healing and the incidence of recurrence will vary significantly based upon the treatment and rehabilitation program chosen.”

“PRP is made up of platelets and several growth factors that can aid in decreasing inflammation and will promote healing.”

“In a recent study it was shown the PRP was successful at returning 80% of horses to their previous level of work at 12 months compared to horses that were not treated.”

“The use of biologics has significantly improved our success in treating tendon and ligament injuries. The rehabilitation program post treatment is extremely important in the success of these treatments and should not be overlooked.”

Reprinted with permission from

Dr. Scott Hopper is a 1993 graduate of the University of Wisconsin College of Veterinary Medicine and a shareholder at Rood & Riddle Equine Hospital in Lexington, Kentucky. He completed a one year hospital internship at Rood & Riddle in 1994, followed by a surgical residency at Washington State College of Veterinary Medicine in 1997. He became board certified in surgery in 1999. Dr. Hopper’s interests include performance and sport horse lameness. www.roodandriddle.com

Racehorse Skeletons are Made Not Born!

by Dr. Larry Bramlage

Board Certified Surgeon at Rood & Riddle

B

one was once thought of as inert endoskeleton, but accumulated knowledge assuaged that belief. Bone is a very dynamic tissue highly sophisticated in its adaptability to increases and decreases in the demands of exercise. It will enlarge to withstand additional load and is capable of reducing its mass when loads regress. As such, bone is the one tissue that is capable of regenerating itself and tuning its anatomy to its needs.

Larry Bramlage, DVM, MS, DACVS “It is ideal for the racehorse to carry the minimum skeleton necessary for traversing the distance of the race, but to carry sufficient skeleton to complete the race without permanent damage. To accomplish this there is great rationale in work specific adaptation of the skeleton to meet the demands it experiences, but to maintain a minimum of redundancy. That is why a Thoroughbred racehorse is the best example of a horse built for speed over a distance.”

“The “art” of training is to use the hypertrophy response to produce a continually stronger athlete, without progressing too rapidly for the bone to adapt, causing injury.”

Reprinted with permission from

The neonate is born with a highly adaptable skeletal model. The phenotype is genetically predisposed but the biomechanical loads that the skeleton experiences with the work the horse is asked to do dictate refinement to the most functional skeleton. Unlike organ systems such as the lungs, where training causes no change in organ size, bones can enlarge to double or triple thickness and tune the enlargement to the best shape to neutralize the demands placed on it. The well-known changes in a horse’s shins are the most obvious example of this.

The talented racehorse carries skeletal adaptation to an extreme. Race training literally molds the juvenile skeleton into a racehorse skeleton; a horse is not born with a racehorse skeleton. The skeleton is also tuned for horses of other uses, but the racehorse demands the most of the bone because of the repetitive cyclic load the bone must endure during exercise.

It is advantageous for the horse to carry as little skeleton as possible because skeletal load is deadweight during high-speed exercise. The skeleton’s function during racing and training is to carry the weight of the horse and the rider. Redundant bone strength adds extra pounds and demands extra work to carry those pounds during competition, reducing the horse’s competitive advantage.

That is why a Thoroughbred is sleek and light and doesn’t look the same as a draft horse. It is ideal for the racehorse to carry the minimum skeleton necessary for traversing the distance of the race, but to carry sufficient skeleton to complete the race without permanent damage. To accomplish this there is great rationale in work specific adaptation of the skeleton to meet the demands it experiences, but to maintain a minimum of redundancy. That is why a Thoroughbred racehorse is the best example of a horse built for speed over a distance.

High-level exercise does this by causing minute damage that the bone senses, responds to, and then makes the skeleton stronger. The micro-damage, stimulated by exercise, causes overcompensation by the bone via the modeling and remodeling process, strengthening the bone mass and changing the bone’s shape to make the bone stronger and prevent the micro-damage from occurring again in subsequent exercise sessions. If the exercise is then increased again, the bone is overloaded again and over-repairs again further strengthening and modeling the bone to neutralize the load. This stepwise stimulus of hypertrophy by “overload” then “over-repair” is the basis for training in all tissues but is particularly important in bone.

Bone senses load by determining tension and compression. Compression deformation always dictates bone formation to increase strength, whereas tension tends to create remodeling to alter a bone’s shape. The compressed surface of the bone strengthens the bone internally by adding to the bone density, and models the external surface of the bone by adding bone mass to the most heavily loaded areas. This shapes the bone to best resist the stress of training. The dorsal surface of the cannon bones and the caudal surface of the tibia are very active examples of this bone modeling to neutralize ongoing bone deformation. Over time the modeling/remodeling process alters the bone to the shape and strength that best prevents deformation upon loading. At this point the load is balanced on the long axis of the bone for the horse’s workload. The modeling process then slows or ceases as long as the exercise load is not altered, but the remodeling has to continually occur to repair “wear and tear” which results during all exercise.

The bone’s ability to respond to training is, however not an unlimited resource. There is a maximum rate of response that the bone can generate. It takes time for the osteocytes (the bone cells) to increase the density of the existing bone and for the osteoblasts (also bone cells) to change the size of the bone. The “art” of training is to use the hypertrophy response to produce a continually stronger athlete, without progressing too rapidly for the bone to adapt, causing injury.

Racehorse Skeletons are Made Not Born!

(continued)

The adaptation of bone to training is different than most tissues because it trains more to the level of work, rather than the volume. Bone requires only a limited number of loads in a specific exercise periods to stimulate its response. Experimentally this has been determined to be approximately thirty-six similar cyclic loads. As the level of exercise increases the tolerable volume of work the bone can withstand decreases and excess work results in damage and lameness. There is some individual variation in the ability to respond to training, as with most biologic systems. Some individuals can mount the response at a rate that virtually precluded their bone being overloaded, and some individuals cannot respond fast enough for even the most moderate levels of training. Overload faster than the bone can respond results in lameness. The non-bone tissues such as the heart and lungs are more sensitive to the volume of work to train, not changes in level of work. So the two differing demands must be balanced to train a racehorse. The art of reading and understanding this biologic variation is the basis for a trainer to properly dose training.

In summary bone is not a purely structural inert material; it is a very dynamic support tissue that adapts to the work it is asked to do. Most lameness is the result of damage in excess of the horse’s ability to respond to the exercise stimulus. Understanding of the horse’s bone response to exercise and modulation and adaptation of exercise programs to individual horses and to their response to the stimulus greatly aids in the avoidance of injury in the equine athlete.

TIE-BACK SURGERY

by Dr. J. Brett Woodie

“Most lameness is the result of damage in excess of the horse’s ability to respond to the exercise stimulus.

Understanding of the horse’s bone response to exercise and modulation and adaptation of exercise programs to individual horses and to their response to the stimulus greatly aids in the avoidance of injury in the equine athlete.”

This is a cross-section of a horse’s cannon bone that shows how much change a cannon bone makes in response to training. The inner circle is the yearling cannon bone the horse started with. The bone that changed the shape and size of the bone was added in response to training.

Board Certified Surgeon at Rood & Riddle QUESTION: I’ve heard there are cases where tie-back surgeries fail after some time. Why might this happen?

DR. J. BRETT WOODIE: A tieback (prosthetic laryngoplasty) is considered the treatment of choice for racehorses that have laryngeal hemiplegia (arytenoid paralysis or“roaring”). The post-operative success rate in improving racing performance in Thoroughbreds is highly variable. Horses with a paralyzed arytenoid cartilage have significant respiratory compromise that manifests with respiratory noise during inspiration and inhibition of performance during exercise.

The goal when performing a tieback is to abduct (pull) the paralyzed arytenoid cartilage out of the airway and anchor it in place. The key is to optimize and maintain that arytenoid position in order to maximize airflow while minimizing aspiration of feed and water. This is achieved by placing nonabsorbable suture(s) that act a prosthesis for the paralyzed muscle that is responsible for abducting the arytenoid cartilage up and out of the airway.

Loss of abduction (or the amount that the arytenoid is “tied back”) has been considered the main reason for failure of the procedure. The loss of abduction decreases the diameter of the airway, causing interference with airflow leading to decreased performance. The vast majority of tiebacks do lose some abduction during the first six weeks post-surgery.

The cause is unclear and is probably multifactorial. Loosening of the suture(s) secondary to suture slippage or the suture(s) cutting into the cartilages where they are anchored are thought to be the main reasons. There are numerous techniques that have been developed to try to minimize abduction loss post-surgery. These include the type of suture used, differing anchoring techniques for suture placement, location of suture placement, and fusion of the joint associated with the arytenoid cartilage. In addition, research is ongoing to develop techniques that will restore airway function while maximizing airway heath in horses with laryngeal paralysis.

Dr. Woodie is a shareholder at Rood & Riddle Equine Hospital, where he is also Director of Medical Services for the Saratoga office. He attended North Carolina State University for his veterinary medical degree and completed an internship and residency at Ohio State

J. Brett Woodie, DVM, MS, DACVS “A tieback (prosthetic laryngoplasty) is considered the treatment of choice for racehorses that have laryngeal hemiplegia (arytenoid paralysis or“roaring”).”

“The goal when performing a tieback is to abduct (pull) the paralyzed arytenoid cartilage out of the airway and anchor it in place.”

Reprinted with permission of the

www.roodandriddle.com

Reprinted with permission of the

by Natalie Voss | 03.01.2018

Bramlage: ‘Price To Pay’ For Bisphosphonate Use Is Delayed Healing “I wish we’d never seen these drugs,” said renowned orthopedic surgeon Dr. Larry Bramlage at the conclusion of a recent presentation about bisphosphonates.

Four years after the Food and Drug Administration approved the use of Tildren and Osphos (both trade names for bisphosphonates) for use in adult horses suffering from navicular syndrome, Bramlage said he’s seeing unintended side effects from people using the drug off label.

As Bramlage explained at a recent client education seminar held by Rood and Riddle Equine Hospital, there are three main types of cells associated with bone repair and growth: osteoblasts, which make new bone; osteoclasts, which break down damaged or inferior bone, and osteocytes, which direct the repair.

Larry Bramlage, DVM, MS, DACVS

“I’ve spent 40 years looking at horses’ bones trying to understand the process of damage and repair that we consistently deal with in the racehorse. In the last two years we’ve had horses’ injuries that don’t behave anything like they did in my first 40 years,” he said.

“We can no longer depend on the repair process that we have come to expect as normal for the horse.

Bisphosphonates also ‘mute’ the normal bone turnover we depend on in bone scans.”

To watch Dr. Bramlage’s entire presentation from the Rood & Riddle Client Education Seminar

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When a horse has a fracture, the crack is initially filled by the osteoblasts with a temporary boney substance called woven bone, which can be made very quickly but is not very strong.

Over time, osteoclasts clear away woven bone, which is poorly organized and weak, allowing osteoblasts to lay down the better organized and stronger lamellar bone. The lamellar bone fills in the crack and makes the bone whole again, both practically and on radiograph.

Bones are constantly breaking down and building back up in response to normal wear and tear and training.

Bisphosphonates work by poisoning osteoclasts and for this reason are used to slow osteoporosis in people. They also have an analgesic effect, which is why they are used in human bone tumor patients. This is also why they are presented as an option for horses dealing with painful and hard-to-pinpoint inflammation due to navicular syndrome.

Bramlage is finding bisphosphonates’ mechanism of action also disrupts the natural healing process in young horses during training.

“I thought initially it might create a lot of acute fractures,” he said. “I don’t think it increases their incidence very much. Where it causes a problem is whenever you’re trying to heal something that’s happened as a result of training and needs to repair. Part of the horse’s natural coping mechanism is disabled.”

Bramlage is seeing stunted healing on radiographs of horses who have had surgery or rest to repair fractures which normally would have improved in a couple of months. Sometimes as much as 14 months after injury, the x-rays still show the injuries that have been “patched up” with woven bone still persist with original fractures visible.

“I’ve spent 40 years looking at horses’ bones trying to understand the process of damage and repair that we consistently deal with in the racehorse. In the last two years we’ve had horses’ injuries that don’t behave anything like they did in my first 40 years,” he said. “We can no longer depend on the repair process that we have come to expect as normal for the horse.

Bisphosphonates also ‘mute’ the normal bone turnover we depend on in bone scans.”

Bisphosphonates don’t stop horses from making new bone, which Bramlage says is the reason the drugs don’t seem to be causing fractures. They do stop osteoclasts from clearing the weak woven bone out of the way of osteoblasts putting in the strong stuff. The radiographs show new layers of bone being added over cracks but not remodeling of the fractures themselves. As a result, a horse’s bone gets denser on the radiographs because of the added woven bone but it doesn’t get stronger or repair. Bramlage said the drug does nothing to prompt osteoblasts to work harder as some have theorized, so it doesn’t speed this layering process, either.

Bramlage: ‘Price To Pay’ For Bisphosphonate Use Is Delayed Healing (continued) This mechanism doesn’t raise the same problems in pleasure horses because their bones aren’t subjected to the volume of stress and rapid need for repair.

Bisphosphonates can cause problems healing bones in humans, too. Bramlage recently spoke to several human surgeons about patients who are unlucky enough to break a bone after they’ve been on bisphosphonates to prevent osteoporosis.

“If you break your femur, which is a common injury of patients on bisphosphonates, in a normal case they make you non-weight bearing for six weeks. They’d give you crutches and a walker for six weeks. At about three months, you can be weight bearing again,” he said.

“If you’ve had bisphosphonates they’ll make you non-weight bearing for up to eight months because that’s how much it slows healing in people.”

All of this seems to Bramlage like a poor trade-off for a pain-relieving effect that probably wears off in about 30 days. (Bisphosphonates are shown to attach to the bone’s surface after administration and persist for years even after just one dose. Repeated doses cause cumulative levels on the interior surfaces of the bones.) Bramlage said it’s important to note that because of the drug’s long life on bone surfaces, a trainer currently in possession of a horse may not be the one who originally gave the horse bisphosphonates and may not even know the horse has been exposed to the drug.

“Unfortunately a lot of people who are giving it and are having it given, don’t understand the price. They see a temporary improvement in the horse’s lameness and they don’t understand that what happens months later may be related,” he said. “The people who are in charge when the horse gets the drug don’t have to be in charge when you’re trying to rehab the horse and get it back to racing. So the lay-up facilities, the owners, and the horses pay the price for the remodeling debt precipitated by the use of the bisphosphonates. I am convinced some horses that we would have rehabilitated effectively in the past never make it back to form because of their history of bisphosphonate use.”

The issues Bramlage is seeing are in horses that have been given bisphosphonates outside manufacturer guidelines. The guidelines state the drugs should not be administered to horses under the age of five. A quick look at the drug literature will make the intended use clear.

“If you’re interested in using them, you should go to the manufacturer’s website because more than 50 percent of the package insert is telling you why you shouldn’t use them in young horses,” he said. “However, they’re perfectly willing to sell them to you for use in young horses. All of those disclaimers are meant to put the blame for anything bad that happens to your young training horse on you and not the company.”

Bisphosphonates became a concern for racing regulators in 2015 when the Kentucky Equine Drug Research Council announced its intent to study the drugs after receiving information some managers and trainers could be using it for its analgesic effect.

In England, the British Horseracing Authority issued a mandatory 30-day stand-down period for horses receiving bisphosphonates and prohibits their use in horses less than 3 1/2 years of age. Unfortunately, the drug is difficult to test for and Bramlage worries the temptation of general analgesia can prove too much for some horsemen.

“Routine use of it I think is accelerating on the racetrack based on the number of horses we see that don’t follow the normal healing pattern,” he said. “That’s a temporary fix, and there’s a price to pay.”

Larry Bramlage, DVM, MS, DACVS “The issues Bramlage is seeing are in horses that have been given bisphosphonates outside manufacturer guidelines.

The guidelines state the drugs should not be administered to horses under the age of five. A quick look at the drug literature will make the intended use clear.”

“Bramlage said it’s important to note that because of the drug’s long life on bone surfaces, a trainer currently in possession of a horse may not be the one who originally gave the horse bisphosphonates and may not even know the horse has been exposed to the drug.”

by Natalie Voss | 03.01.2018

Reprinted with permission of the

www.roodandriddle.com

NaturalHoof Now Readily Available!

Dr. Morrison and the Podiatry team at Rood & Riddle worked closely with nutrition consultants to create a Hoof Supplement that provides an ideal environment for the hoof to grow, strengthen and rebuild.

Rood & Riddle Veterinary Pharmacy is currently distributing this supplement exclusively. If you have any horses that need supplemental hoof support, consider NaturalHoof.

Key in the formulation of this supplement is Dr. Morrison’s strong stance that horse owners are, in general, over-supplementing horses. A balanced diet for our horses includes a full spectrum of the trace minerals for a healthy horse and supplementation should be need-based.

We are seeing great success from horses being supplemented with NaturalHoof.

The hoof pictured (left) is after 8 weeks of supplementation (the new growth is very apparent at the top of the hoof).

The idea was to find the right ingredients for hoof growth, from the most bio-available sources, to address a specific problem. There are no unnecessary ingredients in this formula, meaning no oversupplementation. Not adding unnecessary “buzzword” ingredients means Performance Equine Products was able to spend extra money and effort finding the best source for the ingredients desired.

These images show the same hoof after 3 months on the supplement.

Contact Rood & Riddle Pharmacy for more information (859)246-0112 or info@rrvp.com

Dr. Katherine Garrett becomes newest Shareholder Rood & Riddle Equine Hospital is proud to announce the newest shareholder to the practice.

Dr. Katie Garrett became the 24th shareholder in January of this year. Based in Lexington she is currently on the surgery staff and is the director of diagnostic imaging at Rood & Riddle.

Dr. Katie Garrett attended Dartmouth College in Hanover, NH, where she obtained her Bachelor of Arts degree in biochemistry and molecular biology in 1999. She then attended veterinary school at Cornell University in Ithaca, NY, graduating with distinction in 2003. Dr. Garrett completed two internships (2003-2005) and an equine surgery residency (2008-2011) at Rood & Riddle Equine Hospital, achieving board certification in the American College of Veterinary Surgeons in 2012. Her main area of interest is diagnostic imaging, with particular interests in musculoskeletal MRI and laryngeal imaging.

Katherine Garrett, DVM, DACVS

Dr. Deborah Spike-Pierce, CEO, said “We are delighted to have Dr. Garrett as a shareholder in Rood & Riddle. She is board certified by the American College of Veterinary Surgeons and serves as the director of diagnostic imaging at our hospital. Her unwavering commitment to excellence is a tremendous asset for our imaging department and the hospital as a whole.”

200 Acre Reproduction Center Opened Rood & Riddle’s new reproduction farm is now fully operational. Whether it be a mare or stallion, embryo transfer or frozen semen, Rood and Riddle is ready to take care of your horses’ reproductive needs. This 210 acre farm includes a stallion barn, a laboratory, a breeding shed, offices, as well as room for their expanded recipient herd and stabling for client owned mares.

Rood & Riddle’s boarded theriogenologists include Drs. Etta Bradecamp, Maria Schnobrich, Charlie Scoggin and Stephanie Walbornn, and the reproduction staff includes technicians, Crystal Howard, Amanda Swinson and Caitlyn Benedetto and administrative assistants Mary Yozwiak and Amy Funck.

The new facility allows the Rood &Riddle reproduction team to stand and collect stallions for domestic and international purposes. The Stallion Barn is currently approved to house stallions to export semen to the European Union, Australia, New Zealand, South America and the Middle East.

Rood & Riddle Reproduction Center

For more information on our facility watch our video or Call 859-280-3416

2018 Annual Client Education Seminar Rood & Riddle hosted it’s 33rd annual Client Education Seminar on February 22 at the Embassy Suites. The Rood & Riddle clinicians took the stage and gave presentations to an audience of over 300 attendees. Each presentation given was in response to a question that had been previously submitted via the Rood & Riddle Facebook page.

In all, 22 questions were answered by 18 of our clinicians. Question topics included Hydrops, Sigafoo Shoes, Broodmares & Colic, Lacerations, Endometritis, Atrial Fibrillation, Bacterial Meningitis, Twin Pregnancies, Lawsonia, Fetal Sexing, Dentistry, Cervix Reparation, Jaundice Foals, EVH-1, Anesthesia, Stifle OCD’s, and Bisphosphonate use.

Maria Schnobrich, VMD, DACT

Each of the question videos is being released on our Facebook and YouTube pages. Here is the link to view theriogenologist Dr. Maria Schnobrich answer the question “Do you have any new treatments or recommendations for treating mares with chronic endometritis?”

We hope to see you at next year’s seminar!