August 2019 - Equine Nutrition
With so many supplements and grain options, how should you know what to feed? Join us this month as our expert, Dr. Alison Cornwall answers your questions concerning equine nutrition.
Click here to read this month's questions and answers.
Sport Horse Injuries: Preparing for Rehabilitation
- My veterinarian advised placing Nanric ultimate wedges on my laminitic mare with no radiographs or a plan of action discussed. The veterinarian abandoned treatment with no follow-up only advising me to keep the horse on stall rest 24-7. After a month, the smell coming from the wedges made obtain expertise from another veterinarian. The wedges were removed only to reveal both front hooves had small holes in the soles at tips of frogs. Radiographs were taken that same day, which showed minor rotation. We are now into month two, treating these holes at great expense. Were the wedges used properly? (View Answer)
First of all, I am sorry that your horse has developed laminitis, it is a painful, frustrating and complicated disease to treat. Without seeing the initial visit summary from the veterinarian, it would be hard for me to evaluate whether the pads were used in the manner that they are meant to be used or not. NANRIC Ultimates are a heel wedge shoe that can be either glued or bandaged onto the horse’s foot when they first begin to exhibit signs of laminitis. They are not intended to be used to manage chronic laminitis. The NANRIC Ultimate is designed to be used at the first sign of laminitis to help prevent the pedal bone from rotating or sinking. It does this by improving blood flow within the foot. The design of the shoe effectively moves the loading of the foot further back to the heel and relieves pressure on the front of the foot. This lessens the tension on the Deep Digital Flexor Tendon, the tendon that attaches to the bottom of the pedal bone. It is the tension on this tendon coupled with inflammation and separation of the laminae (the tissue that connects the pedal bone with the hoof wall) that allows the pedal bone to either rotate and tip toward the ground or to sink within the hoof capsule.
Not all horses are candidates for simple application of the NANRIC Ultimates and the manufacturer provides excellent guidelines for their use. Prior to application, radiographs should be taken to determine the position of the pedal bone within the hoof capsule. If the horse has a Palmar Angle (PA) greater than 5 degrees the foot must first be balanced differently prior to using the shoe or application can result in increased pressure on the front of the foot, the area we are trying to unload. A very simplistic explanation of the Palmar Angle is that it is the angle made from the back of the pedal bone to the ground. It is also important to look at the conformation of the horse’s foot prior to application. Foot conformation has a huge impact on the effect of applying wedges, so applying a wedge to a foot improperly can have harmful consequences secondary to altered load bearing. If your horse has thin soles, crushed heels, long toes or a negative palmar angle, the NANRIC would need to be altered to change the weight bearing dynamics of the wedge. NANRICs should not be used on horses that have a pedal bone, which is sinking.
I am going to give you a quick rundown on laminitis, assuming this was the first time your horse has experienced this problem. In an acute episode of laminitis, the horse will be noticeably painful on the front feet (this can happen in the hind feet although it is not as common) and reluctant to move, even to the point of not wanting to walk for food or water. She may stand to shift weight off the front feet by rocking back or leaning his rump on a solid object. Often horses will shift weight back and forth between each front foot continuously. In very severe cases, horses will spend a lot of time laying down. When the veterinarian comes out he or she will check for elevated heart rate, check the quality of the digital pulses on all of the legs, assess pain status by trying to move the horse, as well as evaluating the overall health status of the horse as part of the normal physical examination. Once a diagnosis of laminitis has been made, the horse will be given a Non-Steroidal anti-inflammatory medication IV such as phenylbutazone or flunixin meglumine, radiographs of each foot with be taken to assess the placement of the pedal within the hoof capsule and the alignment of the distal bones of the leg, some type of heel elevation method will be used based on the radiographs (NANRICs), and the veterinarian may add additional medications for the horse on a case by case basis. The owner will likely be left with oral anti-inflammatory medications like phenylbutazone or flunixin meglumine and gastroprotectants like Ulcergard to give daily, and the horse will be placed on strict stall rest with heavy bedding. Food and water should be placed in easy reach of the horse. The horse will need careful monitoring and radiographs are often taken weekly until the veterinarian feels the horse has stabilized. A common sequela of laminitis is the development of abscesses in the foot or in the case of a severe laminitis, prolapse of the pedal bone through the sole at the front of the foot. By your explanation of the foot and the radiographs, I am guessing that your horse developed abscesses in both front feet secondary to the laminitis. If this is not the case, then pedal bone prolapse should be suspected and addressed. Abscesses should clear up over time with proper management and foot balance. Pedal bone prolapse is much more complicated to manage and may require consultation with a specialist. To give your horse the best chance at a positive outcome, it will be important to continue to monitor the balance of your horse’s pedal bone within the hoof capsule and come up with a regular hoof trimming/shoeing program to make sure that you keep the foot balanced. Additionally, you should speak to your veterinarian to try to determine why your horse experienced this episode of laminitis and address any underlying health issues present. Continued thoughtful monitoring of your horse’s progression and a good working relationship with your veterinarian will be critical for her success. I wish you and your horse all the best for a positive outcome. Terri Van Wambeke, DVM, Oregon City, OR
- We had a fairly major carriage accident Sunday. Injury to our 11-year-old Holsteiner gelding sustained an injury to his SDF tendon - subluxating and luxating just above and over the hock. After two days, the tendon seems to be staying in the "luxated" position. I understand this type of injury is fairly uncommon and our local veterinarians have little information. They have recommended 4-6 months stall rest with a "fair" prognosis for return to a competitive driving (CDE) career. Can you provide more information on this type of injury and the courses of action and prognosis? (View Answer)
I am sorry to hear about the carriage accident and injury to your horse, I wish him an incident free rehabilitation. Although the injury you are describing is uncommon, subluxation of the superficial digital flexor tendon (SDFT) over the calcaneus (point of the hock) generally occurs following some type of trauma. Occasionally, horses will also present with SDFT subluxation following something seemingly benign like a bucking episode or exuberant play. You didn’t state to which side the tendon has subluxated so I will guess that it is the more common lateral or outside of the hock. I will give you a brief overview of the injury with some options for diagnostics.
The SDFT originates on Femur in the upper leg, then runs over the back of the calcaneus (the point of the hock/tarsus) and inserts below the fetlock on the bones of the pastern. It functions in flexion of the lower leg and extension of the hock joint. As the SDFT runs over the point of the hock it forms a fibrocartilage cap. It is in this area that the SDFT forms strong connections on either side of the tendon. These connections stabilize the tendon and prevent it from slipping on and off the calcaneus during movement. Think of these as anchors holding the tendon in place as it runs over the point of the hock. Injury to these connections and/or the fibrocartilage cap allows the SDFT to slip to one side or the other. Imagine removing or weakening the hold of one of those anchors, the other would still be strong and therefore pull the tendon over to that side, resulting in subluxation. Most frequently, the tendon will fall to the outside of the point of the hock but occasionally, a subluxation to the inside will occur.
Because SDFT subluxation is usually caused by injury to the hock, radiographs should be taken to rule out fracture of the underlying bone. Once radiographs have been completed, a thorough ultrasound examination of the SDFT and its associated structures, including the calcaneal bursa, is very important to formulate a treatment plan. Initially, there will be significant swelling at the point of the hock, mimicking a capped hock, and significant lameness. As the swelling recedes, it will be easy to palpate the displacement of the tendon. Often the tendon can be manually replaced in the correct position but flexion of the limb will often cause it to move off to the side again. The most important deciding factor for future prognosis is the stability of the subluxation and damage to the underlying structures. Horses with stable subluxations usually have injuries at the SDFT insertion sites, and have a better chance at returning to full work after time off than those with unstable subluxations. Horses with unstable subluxations, those in which the tendon moves back and forth over the calcaneus, do not have as favorable a prognosis for return to work. These horses often exhibit anxiety due to the constant slippage of the tendon and tend to have more damage to the fibrocartilage. Although surgery has had mixed outcomes, these horses are candidates for surgical evaluation and possibly repair. All horses should be placed on stall rest for 4-6 months.
If not already performed, I would recommend a complete set of radiographs of the hock, followed by a thorough ultrasound examination. Pending the results of the exam, your veterinarian can decide if a surgical consultation is warranted. It sounds like your horse has a stable subluxation, which carries a more favorable prognosis, but in the absence of a complete set of diagnostics it is difficult to predict your horse’s future athletic potential. You are on the right track already by committing him to stall rest and I wish him a speedy rehabilitation. Terri Van Wambeke, DVM, Oregon City, OR
- I have an off-the-track Thoroughbred that bowed a tendon in his last race. I would like to train him as a jumper after the bowed tendon has healed. What can I do to help the tendon heal properly? What should I use and how long should I give the tendon to heal? (View Answer)
This is a great question as tendon and ligament injuries are probably the most common injuries causing horses to need protracted lay-up and rehabilitation. My first recommendation would be to find a good equine ultrasonographer in your area and get an ultrasound examination of the injured tendon. This examination will serve as the baseline from which your veterinarian will determine how to proceed with rehabilitation and treatment. The length of rehabilitation, additional treatments and future prognosis will depend on the amount of damage to the tendon fibers and the way they are reorganizing and repairing.
Tendons are made up of bundles of fibrous connective tissue strands organized parallel to the leg. Imagine tendons like ropes made of individual fibers that form a very small bundle, then those bundles create another bundle, this goes on increasing in size until a very strong single bundle made of many bundles of fibers is created. Tendons connect muscles to bones and function much like a spring, storing energy during loading then releasing energy, like a spring recoiling, during unloading. During injury, damage occurs to either individual fibers or to bundles of fibers as they pull apart much like a rope begins to look frayed in the middle as it becomes overstrained. With a new injury, one will see pain, heat and swelling, the hallmark signs of inflammation, and varied degrees of lameness. In a chronic injury, lameness may or may not be present, and the tendon will be thickened without much pain or heat. Unfortunately, during repair of tendons and ligaments, the original organization and strength of the repaired fibers is often not a good as prior to the injury. This can leave the horse with a weak link at the site of injury. Careful rehabilitation, monitoring, and possible adjunct treatments can help increase the odds of full return to a successful career.
Initially, horses will need strict stall rest and oral anti-inflammatory treatment (such as phenylbutazone or flunixin meglumine) to minimize loading on the damaged tendon. Controlling the environment this way allows the body to create more organized repair tissue and minimizes adhesion formation. The worst thing for a damaged tendon is exposure to high loads during heavy exercise or exuberant play. Your veterinarian my also recommend icing, wrapping, topical anti-inflammatory agents and in-hand mobilization exercises to benefit range of motion of the leg. Generally, a few weeks after the injury has quieted down your veterinarian will recommend to begin hand-walking for a specified period each day. The length of time of hand walking will increase every few weeks depending on how your horse’s tendon is looking. Trot work usually begins 3-4 months after an injury and canter work around the 5-6 month range. Turnout is contraindicated until the horse is back to full work and ultrasound examinations are looking stable. It is important to make sure you have good footing for the horse during this period, not too deep, not uneven or hard, not slippery. If the horse becomes too fractious you may need to speak to your veterinarian about how to safely continue with rehabilitation. It takes about 6-9 months to get a horse back to full work after a tendon injury. Throughout this entire rehabilitation, it is critical that period ultrasound examinations be performed every 30-60 days, depending on the severity of the injury. Additional ultrasound examinations are warranted if there is any change in the appearance of the tendon or lameness. It is important that you palpate the leg daily to closely monitor any changes in pain, heat or swelling at the injury site. If you notice any changes you should contact your veterinarian immediately. I’m not sure how long it has been since your horses’ injury but there are biological therapies that are helpful to promote more organized tendon healing. These include the use of platelet-rich plasma (PRP) or stem cells. These therapies utilize the body’s own healing properties, with the help of science. Tissues are collected and incubated to increase the healing properties present, then they are injected, using ultrasound guidance, directly into the lesion(s) in the tendon. They help the body create a better healing environment and improve tendon organization and strength. You would need to consult with your veterinarian to determine if a biological would be of benefit to the horse. If so, these are a great adjunct to the traditional rest and rehabilitation program.
There are some great options out there to assist with rehabilitation. Underwater treadmill is a great tool for allowing the horse to begin heavier work without a huge increase in load on the tendon. These treadmills offer a wonderful way to maintain fitness and allow the horse to more safely burn off some energy in the process. Eurociser type horse walkers, that have individual moving stalls instead of head ties, are a good tool to gradually increase exercise time and type. They are safer for the handler when you have a horse that is becoming dangerous to walk in hand for lengthy periods of time or for beginning trot work if the horse is unsafe to ride.
Make sure that you keep the horse in healthy weight and avoid allowing him to become overweight, generally not an issue for an OTTB.
There are some shoeing changes that you can speak to your farrier and veterinarian about. You can place different shoes on the horse during rehabilitation that help support its specific injury. At a minimum makes sure that you remove any racing plates and have correct balanced shoeing.
Some modalities that I have had success with and regularly use in the treatment of tendon injuries include the use of extracorporeal shockwave therapy, therapeutic ultrasound and low level laser therapy (LLLT). You will need to work with your vet or a rehabilitation person for protocols should you decide to pursue any of these additional therapies.
Not to be overlooked is the role of proper nutrition. There is some anecdotal evidence in the human literature that amino acids (leucine, arginine and glutamine and for the horse Lysine), Vitamin C, copper, manganese and zinc may improve tendon healing. Make sure that the horse is on a balanced diet and speak with an equine nutritionist if you are unsure about how to accomplish this.
There is so much information I could write forever on this topic! I hope this has helped answer any questions. Terri Van Wambeke, DVM, Oregon City, OR
- I have a two-year-old Standardbred filly that took a fall, which resulted in a bone chip in her hock. The chip was removed with no damage to the joint. She was rested for 30 days and then light exercise for 30 days. Her results now include hiking her leg that harbored the bone chip. With more testing, an inflamed ACL joint. Both injuries happened at the same time. Now my question is how much more time to rehabilitate? (View Answer)
I am very sorry to hear about your horse’s accident and hope that she is in her way to a complete recovery. Injuries to cruciate ligaments in horses commonly occur secondary to traumatic incidents like you have described. Given your description of the injury I am assuming that the stifle joint itself is still very stable which improves her prognosis. If the anterior (cranial) cruciate ligament is enlarged and inflamed (desmitis) but does not have any large lesions, you can expect pain to subside after instituting strict rest followed by controlled exercise. It sounds like she has already had a complete set of radiographs and a comprehensive ultrasound exam of her stifle combined with arthroscopic exam, but if not, make sure that she has the medial collateral ligament of the stifle ultrasounded at her next exam. These two (CCL and MCL) ligaments are often injured at the same time. The management of tendon and ligament injuries, including repair and healing, is essentially the same process regardless of where in the body it is located. Please read August 2017 Question #3 for information on rehabilitation and healing of tendon and ligament injuries. Depending on the severity of the lesion you should expect your mare to be back to work in 6-9 months. I tend to be more conservative with stifle injuries because they are traditionally more difficult to deal with than injuries in other joints. In addition to committing to stall rest with a controlled exercise program, it will be important to diagnose and treat any underlying inflammation in the stifle joint. This may involve the use of intra-articular injections or topical medication.
You mentioned that she was “hiking” the injured leg. If this was referring to her lameness on that leg, hopefully that will resolve over time with appropriate rehabilitation. If she has developed a change in her gait where she is suddenly bringing the injured leg swiftly upwards during the swing phase of her gait (as the leg moves forward underneath her), you should alert your veterinarian, this could mean she is developing stringhalt. Stringhalt can occur following injury to the hind limb.
Good luck to you and your mare! Terri Van Wambeke, DVM, Oregon City, OR
- We have a client's horse that is exhibiting back soreness. The X-rays for the Prob. spinosi are good, but he is really sore. The clients have a treadmill and a vibraplate. We planed to treat the horse in an initial phase with Methocarbamol and NSAID's, but I would like to integrate the treadmill and the vibraplate in the rehabilitation plan. Do you have suggestions ? (View Answer)
Great Question! Both vertical plate vibration and treadmill would be a super addition to this horse’s rehabilitation plan. Most manufactures of vibration plates have protocols for their systems. You might want to contact the manufacturer to see if they have a protocol for back pain that they recommend. If they do not, I recommend setting the plate at 30 (this is on an Equivibe) or at approximately the 10 O’Clock mark on the dial assuming the off position is at the 7 O’Clock mark. Leave the horse on the plate for 20 minutes 2-3 times each day. Use your treadmill to condition the horse without the weight of the rider or tack exacerbating back pain. Start by gentle conditioning at the walk on the flat then over the course of a few weeks increase the incline until the horse is comfortable walking on moderate incline. This will help build up the muscles of the lower back and hind end. Before beginning trot on the treadmill have your veterinarian evaluate the status of the horses back. If the pain and spasms have diminished, and the veterinarian gives you the go ahead, you can start adding in trot work on the treadmill. After a few months of treadmill and before beginning work under tack, make sure to have another veterinary exam to check for back pain and spasm.
Causes of back pain in the horse are many and it sounds like you have eliminated kissing spines as one cause. A through lameness exam with flexions can help eliminate an underlying lameness as a cause of back pain. Any lameness will need to be treated for secondary back pain to resolve. Ultrasound examination is an important tool to evaluate the joints of the horses back and treat if necessary. Another common cause of back pain is a poor fitting saddle. I have a trained saddle fitter evaluate all horse’s saddles who present with recurrent or severe back pain. I can’t stress the importance of a properly fitting saddle for recovery from chronic back pain. A poor fitting saddle damages the muscles and nerves along the horses back, and unless that cycle of pain is broke, it will be very difficult if not impossible to resolve the back-pain issue. There are also other systemic diseases that can present as back pain that your veterinarian can rule out.
You may want to speak to your veterinarian about adding some extracorporeal shockwave therapy, mesotherapy or trigger point therapy in addition to the oral medications for this horse. Good luck with the rehabilitation program for your client’s horse. Terri Van Wambeke, DVM, Oregon City, OR
- My horse came up lame in his right hind after a night in a safe pasture. There is some heat in the fetlock and I supported the leg for a week with Professional Choice leg and fetlock boot. The swelling has come down but he is still favoring the leg after eight months. I have had hoof testers on the hoof with no reactions except for the inside bulb of the heel. He has now been adjusted twice by a chiropractor for a downward flexion of the right hip. I have administered bute after the adjustments and he seems better but not quite 100%. What can I do for him? (View Answer)
It sounds like you have a long-term undiagnosed lameness going on. Unfortunately, without a diagnosis I am unable to offer much advice. What I can recommend is that you have a veterinarian come out and do a thorough lameness evaluation on your horse. Most mild injuries should have resolved after 8 months so it concerns me that your horse is still lame this far out from the original injury. In the meantime, it would be a good idea to place your horse on stall rest with short walks in hand until you can have your veterinarian out. Hopefully your veterinarian can assist you with getting your horse diagnosed and back to work. Terri Van Wambeke, DVM, Oregon City, OR
- I have a 27-year-old Appaloosa/Quarter horse that has stayed remarkably sound. However, he recently developed a shoe boil and the barn I have him boarded turns him out at night during the summer so a shoe boil boot can't be worn. I use Pro Choice padded bell boots to help some. It is more cosmetic. My dilemma is to take off shoes or not. He is still ridden four times a week and healthy. Will it hurt his tendons to remove shoes when he has had them on for over twenty years? I am a bit paranoid as I am inexperienced with bare footed horses. I could put shoes back on when we start stabling at night? (View Answer)
Great job keeping your older horse comfortable and sound! A shoe boil, swelling over the point of the elbow, also referred to as a capped elbow, is inflammation of the synovial structure that protects the point of the elbow from trauma. These need to be watched closely for heat and pain because they can become infected if punctured or seriously irritated. Your veterinarian may recommend cold hosing and some topical anti-inflammatory agents to help bring the swelling down for a simple shoe boil. I don’t recommend trying to drain the area to decrease the size of the swelling. The point of the elbow is a great area for bacteria to live and you don’t want to invite an infection. The best thing you can do is to decrease the pressure and irritation to that area. Most often the cause of the shoe boil is pressure from the back of the horse’s shoe (the shoe usually extends beyond the length of the hoof) as the horse lies down with the feet tucked underneath the body. That said, shoe boils are not always caused by a shoe pressing on the elbow. Other possibilities include laying down on a hard surface (un-bedded stall, hard packed dry lot or pasture) or a horse laying down for longer than normal periods of time. If you have ruled out other causes like these, you should check with your farrier to see if he or she has made any changes to the shoeing recently. If so explain the problem your horse is having and see if the shoes can be changed back to the way they were before the shoe boil. If not, you can ask the farrier to bring the back of the shoe further under the foot (shorten the length of the shoe so that less shoe is sticking out behind the foot) and see if that helps with the pressure. It sounds like the bell boots are not solving your problem so here are some other options. If your horse is in a situation where he can tolerate a wrap during turn out, you can place a foot wrap on for the evening with extra padding over the back of the shoe. Another option is to get a firm wearable boot for turn out that goes over the foot (with the shoe on) and see if that dissipates the pressure by covering the extended part of the shoe. I would not recommend removing your horse’s shoes unless both your farrier and veterinarian agree that your horse would do well in that situation. Your horse is doing well as a 27 year old so I wouldn’t want to make any drastic changes. Terri Van Wambeke, DVM, Oregon City, OR
- Recently, I started my two geldings, 23-year-old Quarter horse and 17-year-old Lipizzan in Working Equitation. After a few weeks, both had developed soreness in their hocks. Both boys receive monthly injections of Adequan and Legend. I had their hocks injected and then started hand walking them up and down hills, along with walking, lateral work, long trotting and then cantering. Both have greatly improved their movement (prior to hock injections, no unsoundness, but soreness), of which I gradually reintroduced some pattern work. Thus far, all is going well. Are there other things I can do to keep them moving freely without pain? We do 30-minutes up and down hills 3x weekly. After each ride, we then do a few minutes of hill hand walking for 10 to 15 minutes. I use grazing muzzles when needed to control their weight. Our riding time is much more frequent in the summer months than the winter months. Any advice is appreciated, they are both very willing, and seem to enjoy the obstacles. (View Answer)
I will try to provide some helpful information. Good job with recognizing that your horses were uncomfortable and addressing the issue. It sounds like you backed off on the heavy work and have taken the time to slowly bring them back into condition focusing on strengthening which is great. I would recommend keeping both horses on Adequan and Legend and consider looking at the feeding program making sure neither horse is overweight (the grazing muzzle is a super idea) and that you are providing a balanced diet. Make sure they have enough protein and that it is balanced with lysine, methionine and threonine (the first three limiting amino acids for horses). This will help your horses maintain muscle mass, which becomes more difficult as animals age. Ration balancers can be a great way to provide balanced protein without adding unnecessary calories. Adding some anti-oxidants and some Omega fatty acids (Omega-3 are the good anti-inflammatory essential fatty acids) will help the body repair the daily tissue damage that occurs with work. Fatty acids are also a good way to provide calories without adding carbohydrates that can be a problem for aging horses.
One of the best ways to avoid pain and injury in any athlete is to maintain a strong balanced body. In a horse, keeping their back and core strong helps decrease uneven loading patterns, and lowers strain on the rest of the body. This is best accomplished through a regular conditioning and strengthening program. To help build and maintain core and back strength consider working your horses over trotting poles a few days each week. Start with the poles on the ground and as their strength increases you can slowly raise them until you reach cavaletti height. Your trainer should be able to help you determine the right distance between the poles, remembering to always use an even number of poles. I start with two poles and work up to a line of 4 or 6 poles. When hill work is not an option, work using The Equiband System can help maintain abdominal and hind end strength, even more so when combined with pole work. A veterinarian experienced with rehabilitation or a skilled trainer can help you introduce these to your horses. There are some publications that provide excellent equine core strengthening exercises that you can do un-mounted daily (Activate Your Horse's Core: Unmounted Exercises for Dynamic Mobility, Strength and Balance, Stubbs and Clayton). They are quick and easy to incorporate into your daily routine and are a great addition to a regular conditioning program. Hill work is fantastic and I encourage you to continue with that if the weather permits. As you advance up the training schedule in Working Equitation it would be a good idea to have your vet do a quick lameness exam on your horses every 6 months. As speed and complexity of obstacles and patterns increase, there will be more physical demands on your horses. Bi-annual veterinary exams will allow you to be proactive with your horse’s care, catching issues early, and hopefully extend their longevity as performance horses. I admire your commitment to the health and happiness of your horses. Good luck in your new adventure with Working Equitation! Terri Van Wambeke, DVM, Oregon City, OR