Veterinarians at Rood and Riddle Equine Hospital answer your questions about sales and healthcare of Thoroughbred auction yearlings, weanlings, 2-year-olds and breeding stock.
Question: What, if any, special considerations should owners have for wintertime hoof care?
Dr. Craig Lesser, Rood and Riddle Equine Hospital: Winter in Kentucky, aka mud season, can have some challenges when it comes to your horse's feet. Feet tend to start growing slower and are often saturated in mud without a chance to dry out. This can result in a variety of issues that you should keep an eye out for.
White line disease is a mixed anaerobic bacterial infection that occurs within the hoof wall. Mild infections can be picked up by your farrier and can be treated without much change in your horse's work. However. in more severe cases radiographs and large resections may be necessary to open the infected area up to oxygen and allow for debridement and treatment of the infection.
Bruises and subsolar abscesses are also very common in the winter due to the changes in weather and temperature. The hard to soft ground can soften feet and make them more prone to concussion-related injuries, and this constant swelling and contracting can open areas for infections to fester. Horses with abscesses present acutely lame and once drainage is established, they return to soundness quickly. However, it is very important to protect the abscess tract from filling back up with mud or your horse may re-abscess.
Retracted soles are often a problem with thin-soled feet. They result when mud builds up in the sole and eventually builds enough pressure to force the cornified sole up into the soft tissue structures of the sole of the foot. This can lead to seroma or abscess formation and if not treated properly they often lead to severe complications.
While we don't usually get much snow in Kentucky, horses in more northern regions can have issues with snow and ice building up in their shoes. The formation of large balls of ice on the bottom of a horse's foot can make it difficult for horses to walk. Many farriers will add snow pads to help with this, but nothing is as helpful as ensuring you pick out your horse's feet daily.
Horses with softened feet that are turned out in the mud are also more prone to losing shoes. An increase in the number of lost shoes as well as the decreased growth can make a farrier's job more difficult this time of year.
It is vital that you check your horse's feet daily and make sure to pick them out so they have a chance to dry and recover. If not, it could lead to some much scarier conditions such as canker, septic pedal osteitis, or even quittor.
Dr. Craig Lesser, CF graduated from Colorado State University College of Veterinary Medicine in 2015. Following the completion of an internship at Anoka Equine, he moved to Lexington to complete a podiatry fellowship at RREH and has continued there as an associate. As an extension of podiatry, Dr. Lesser has an interest in lameness and imaging.
The latest issue of the Back Ring is now online, ahead of the Keeneland January Sale.
The Back Ring is the Paulick Report's bloodstock newsletter, released ahead of, and during, every major North American Thoroughbred auction. Seeking to expand beyond the usual pdf presentation, the Back Ring offers a dynamic experience for bloodstock content, heavy on visual elements and statistics to appeal to readers on all platforms, especially mobile devices.
Lead Feature, presented by Gainesway: Bloodstock editor Joe Nevills makes five fearless predictions for the bloodstock market in 2022 in his “Making Claims” column.
Stallion Spotlight, presented by New York Thoroughbred Breeders, Inc.: The New York Thoroughbred Breeders, Inc. Stallion Season Auction is a crucial fundraiser for the breed organization each year, but the 2022 renewal reaches even further to help those recovering from the December tornadoes in Kentucky.
Ask Your Veterinarian, presented by Kentucky Performance Products: Dr. Craig Lesser of Rood and Riddle Equine Hospital explains what horse owners should take into consideration to protect hooves during the winter months.
Pennsylvania Leaderboard, presented by Pennsylvania Horse Breeders Association: How Li'lbito'charm, a daughter of Smarty Jones, brought in six figures worth of Pennsylvania incentive earnings for her connections in 2021 without entering a single stakes race.
First-Crop Sire Watch: Stallions whose first crops of yearlings are represented in the Keeneland January Sale, including the number of horses cataloged and the farm where the stallion is currently advertised.
Veterinarians at Rood and Riddle Equine Hospital answer your questions about sales and healthcare of Thoroughbred auction yearlings, weanlings, 2-year-olds and breeding stock.
Question: Why are broodmares so prone to colic, and what colic causes are most common for them?
Dr. Katy Dern, Rood and Riddle Equine Hospital: According to the Centers for Disease Control, 1.4 percent of human delivery hospitalizations in the United States in the year 2014 developed what are characterized as severe maternal morbidities. This means that, even in closely supervised and intensively managed births, 1.4 in every 100 women developed potentially life-threatening complications. Parturition (birth) has potential consequences for the mother, and broodmares are no exception to this biologic reality.
Dr. Kathryn Dern
When we discuss colic (abdominal pain) in the broodmare, the cause of the pain can be broadly divided into two categories: pain originating from the gastrointestinal tract and pain originating from the reproductive tract.
Colic signs attributable to the gastrointestinal tract are a common phenomenon in the broodmare, and can be further subdivided into those conditions seen prior to foaling and those seen in the post-parturient time period (after foaling). Prior to foaling, causes of colic include mild discomfort due to expanding uterine size and fetal movements, as well as displacements or abnormal motility of the large colon, cecum, or small intestine. Mares exhibiting colic secondary to fetal movements or impingement of the gravid uterus on the gastrointestinal tract will usually not have dramatic changes in their vital parameters (heart rate, respiratory rate, mucous membrane color), and will respond to analgesics (pain management). If the mare's colic signs do not respond to pain management or increase in severity, she may have a gastrointestinal issue which can be life threatening to her and/or the foal. In either case, veterinary evaluation is important to differentiate between mild and more severe forms of colic, and to ensure that more aggressive medical and surgical interventions can be instituted if necessary.
After foaling (and sometimes before foaling), gastrointestinal causes of colic can include large colon volvulus (twist) or displacement, cecal dysmotility or rupture, small intestinal incarceration, mesenteric tears leading to loss of intestinal viability, or rectal prolapse. Of these the most discussed and by far most common cause of colic is large colon volvulus. Broodmares are largely overrepresented in the large colon volvulus (LCV) caseload: one study evaluating the distribution of surgical LCV cases at a large referral hospital in California found that half of the admissions were broodmares that had foaled less than 60 days prior to admission. This association between foaling and subsequent development of colonic displacement or LCV has been mirrored in multiple studies across various geographic areas and additional risk factors such as increased hours of stabling, increased feeding of concentrates, decreased dry matter intake, or a recent change in pasture have also been discovered.
Although our research has clearly shown that post-foaling broodmares are likely to develop large colon volvulus, we unfortunately have not yet determined exactly why they are prone to this disease. Common sense dictates that the presence of additional “room” in the abdomen post foaling must play a role, but this unfortunately does not account for the LCV cases we see in geldings, show horses, or preparturient [pregnant] mares.
Recent investigations into the role of intestinal microbiota in the development of colic suggest that significant changes in the fecal microbiota precede the development of colic. The changes in the bacterial population observed in the fecal samples of mares that developed colic are consistent with changes seen in both dysbiosis (imbalance in gastrointestinal bacteria) and inflammatory intestinal disease in other species, including humans. Further investigation into the role of intestinal microbiota in the development of large colon volvulus will hopefully allow us to not only fully characterize the disease process, but eventually identify at-risk mares and intervene prior to development of colonic displacement or volvulus.
Other gastrointestinal causes of post-foaling colic are usually more directly linked to the parturition itself. Cecal bruising or rupture can occur when the foal traumatizes the base of the cecum. These mares commonly present with abdominal discomfort within the first few days of foaling and then progress to signs of septic peritonitis (abdominal infection) if the wall of the cecum becomes devitalized to the point of rupture. Tears in the mesentery of the small colon or small intestine can subsequently trap segments of the small intestine, causing pain from the entrapment itself and, if prompt surgical intervention is not undertaken, these small intestinal segments can become devitalized, endangering the mare's life, necessitating resection (removal of the devitalized area). If the small colon mesentery is affected, the tear itself can often affect the blood supply to the small colon, causing a gradual necrosis (death) of a segment of the small colon requiring surgery.
Reproductive causes of colic are also common in the broodmare, and determining whether colic signs are gastrointestinal or reproductive in nature is one of the primary goals of the colic exam. In the pregnant mare, colic signs attributable to the reproductive tract can range from mild, medically manageable colics due to fetal shifting and increased fetal size, or abdominal discomfort can be a sign of more life threatening conditions such as uterine torsion or preparturient uterine artery hemorrhage. As with all signs of colic, evaluation by your veterinarian is indicated if your mare's colic signs do not resolve or increase in severity. On the farm, your veterinarian may perform a physical, rectal, and/or ultrasonographic exam to determine if referral is indicated.
In the post foaling broodmare, causes of colic signs attributable to the reproductive tract include mild colic signs due to normal uterine contraction and involution, or more severe colic signs secondary to uterine artery rupture, uterine tears, invagination of a uterine horn or uterine prolapse. In the case of uterine artery rupture, the mare will often show signs of abdominal pain if the hemorrhage is limited to the broad ligament (soft tissue structure which suspends the uterus within the abdomen), as the hematoma dissects through the ligament itself. If she is bleeding freely into her abdomen however, she may not show signs of colic, rather exhibiting a high heart rate, anxiety, and increased respiratory rate consistent with blood loss. In these cases, a thorough physical exam, rectal palpation, abdominal ultrasonography, and abdominocentesis (analysis of a sample of the abdominal fluid) can be critical in determining whether or not the mare is actively hemorrhaging.
Uterine tears can present a diagnostic challenge, as they occur during foaling but do not necessarily cause signs of abdominal pain until the leakage of uterine fluid into abdomen causes signs of abdominal infection (septic peritonitis). In these cases, the mare often presents within the first few days after foaling for dullness and depression, fever, and high heart rate. The diagnosis of septic peritonitis is made using abdominal ultrasonography and abdominocentesis. Prompt surgical repair of these tears, often found at the tip of the uterine horn, limits the continued contamination of the abdomen and allows for intraoperative lavage of the abdomen with drain placement for post-operative lavages. Cases of invagination of the uterine horn are often diagnosed and treated on farm, but if they progress to uterine prolapse may necessitate referral for replacement under general anesthesia.
Lacerating or tearing the cervix during foaling is usually not painful and is commonly found later when the mare is spec'ed or when she is cultured. Manual examination of the cervix is required to definitively diagnose a cervical tear, which are usually repaired after the initial swelling from foaling has subsided (approximately three weeks after parturition).
It is important to note that just because a mare had an uneventful foaling does not mean that the foal didn't damage segments of the reproductive or gastrointestinal tract during parturition. In all cases of broodmare colic, evaluation by a veterinarian experienced in broodmare disorders and timely referral, if necessary, are critical to survival of both mare and foal.
Dr. Katy Dern is originally from Colorado and Montana. She attended Washington State University for her undergraduate work, and Colorado State University for her veterinary degree. Following graduation from CSU in 2012, she completed an internship at Peterson and Smith Equine Hospital in Ocala, followed by an internship at Rood and Riddle Equine Hospital. After her internships, Dr. Dern completed a three-year surgical residency at The Ohio State University, while also earning a Master's of Science Degree. She became board certified in equine surgery in 2018 and has been the surgeon at Rood and Riddle's Saratoga hospital since 2017.
Veterinarians at Rood and Riddle Equine Hospital answer your questions about sales and healthcare of Thoroughbred auction yearlings, weanlings, 2-year-olds and breeding stock.
Question: Why and when might a veterinarian decide to perform a C-section on a pregnant mare?
Dr. Rolf Embertson, Rood and Riddle Equine Hospital: Most C-sections are performed as an emergency procedure in the horse. The procedure is usually performed when other methods to deliver a foal have failed. C-sections are infrequently performed during colic surgery on a term broodmare and infrequently performed as an elective procedure in the mare. Indications for the latter would include a compromised birth canal due to a previous pelvic fracture or soft tissue trauma, a compromised cervix, previous episodes of postpartum hemorrhage, and previous difficult dystocias.
Dr. Rolf Embertson
Before discussing success rates, a basic understanding of dystocia in the mare is warranted. Dystocia means difficult birth. In the mare, once the chorioallantoic membrane ruptures (the mare breaks water), a foal is usually delivered in about 20 minutes. If a foal is not delivered within about 45 minutes, the probability of foal survival starts to rapidly decrease. Thus, this can become a true emergency where minutes can make the difference in survival of the foal. Although less of an emergency for the mare, her reproductive future and even her life may also be at risk. The goal should be to deliver a live foal in a manner resulting in a live, reproductively sound mare.
There are essentially four procedures used to resolve dystocia in a mare. Assisted vaginal delivery (AVD) is when the mare is awake, possibly sedated, and is assisted in vaginal delivery of an intact foal. This is done primarily on the farm. Controlled vaginal delivery (CVD) is when the mare is anesthetized and the clinician is in complete control of delivering an intact foal vaginally. This is usually done in a hospital environment. Fetotomy is when a dead foal is reduced to more than one part to remove the foal vaginally from an awake or anesthetized mare. This can be done at the farm or in a hospital. C-section is when the foal is removed through an abdominal and uterine incision. This is best performed in a hospital. These procedures are used as needed to produce the most favorable result.
The success rate for live foals and live mares that go through a dystocia is significantly better when the farms are close to a hospital that can perform these procedures. This is primarily due to the duration of the dystocia prior to resolution, although this can be influenced by other factors. Realistic example: A mare breaks water and 15 to 20 minutes later, the foaling attendants realize they can't correct the head back posture of the foal. Within five to 10 minutes (now 20 to 30 minutes since the water broke) the mare is loaded on the trailer, the mare arrives at the hospital in 15 to 40 minutes (now 35 to 70 minutes into the foaling attempt). A brief exam, IV catheter placement, anesthetic induction within five to 10 minutes (now 40 to 80 minutes overall), attempt CVD for five to 15 minutes (now 45 to 95 minutes). If the attempt is not successful, the team will perform C-section, foal is delivered in 15 to 20 minutes from when the decision was made (now 60 to 115 minutes from when water broke).
Dystocia mares that are sent to our hospital go directly to a dedicated induction stall. The mare is anesthetized, her hind limbs hoisted so her pelvis is about three feet off the floor. The foal is examined, repositioned, the mare dropped to the floor, and the foal pulled out of the mare. This CVD procedure is successful in resolving about 75 percent of hospital dystocias. About 25 percent of the hospital dystocias are resolved by C-section.
Following CVD, about 39 percent of those foals survive to discharge from our hospital and about 94 percent of those mares survive to discharge from our hospital. Following C-section about 30 percent of those foals survive to discharge from our hospital and about 85 pecent of the mares survive to discharge from our hospital.
Elective C-sections have a better success rate. There is about a 95 percent survival to discharge rate for foals and about a 95 percent survival to discharge rate for mares.
Dr. Rolf Embertson graduated from Michigan State University with a Bachelor of Science in Zoology in 1976. He also attended Michigan State where he graduated from Veterinary School in 1979 followed by an internship at Illinois Equine Hospital. Dr. Embertson completed a Large Animal Surgery Residency at the University of Florida, followed by an Equine Surgery Residency at The Ohio State University. In 1986, he became a Diplomate of the American College of Veterinary Surgeons. Dr. Embertson is a surgeon and shareholder at Rood & Riddle.
