Hi there, I was wondering what supplement would be best for a Thoroughbred gelding that has luxation of his hind left stifle. And if a joint supplement alone will help his stifle locking issue. JS

Answer 1:
Dear JS,

I’m going to assume your horse has upward fixation of the patella, not patellar luxation, as this condition is uncommon in adult horses and usually only seen in foals (especially miniature foals) at birth.

It is generally accepted that horses who “lock” their patellas, that is, whose medial patellar ligament gets hooked over the medial trochlea of the femur, improve with conditioning or fitness training. Since it is the quadriceps, or the muscles on the front of the horse’s legs that most need to be strengthened, hill work is particularly recommended, as is driving, or pulling.

If your horse improves with additional, controlled exercise, then no more treatment may be necessary. However, if there is little to no improvement, your veterinarian may suggest other treatments to help your horse. These include corrective shoeing, estrogen therapy, infusion of a counterirritant or “blister,” or, as a last resort, medial patellar desmotomy surgery, where the ligament that gets hooked over the femur is cut.

I have been asked before if a supplement containing silica and collagen would be appropriate for a horse with upward fixation of the patella and my answer is: I don’t know. On the one hand, part of the conditioning or fitness training is to develop stronger tissues, and having the building blocks of strong ligaments available during this time would make sense. On the other hand, if the ligament develops without corresponding muscle development, would the problem get worse? I do think that supplementing with anti-inflammatories may be indicated, but ask your veterinarian before starting your horse on one.

I have a 10yo quarter horse who’s never had any soundness issues. We do a lot of hacking out and he gets ridden 6 days a week, 2 are serious training days about one to two hours each. We are moving up to Novice eventing this season. Would you suggest any joint supplements? I have heard feed through joint supplements are a waste of money. I am considering Adequan injections. SS

Dear SS,

Congratulations on your success in eventing and on having such a happy, healthy partner! You sound like an intelligent, caring horsewoman, so I took the time to actually look up some research papers for you to read yourself and make an intelligent, informed decision about the benefits of oral joint supplements.

The following papers have all been presented at the American Association of Equine Practitioners Annual Convention, meaning they have been peer-reviewed by other veterinarians and scientists for quality of research:

Effects of an Oral Nutraceutical on Clinical Aspects of Joint Disease in a Blinded, Controlled Clinical Trial: 39 Horses (2007)
Keegan and others from the College of Veterinary Medicine at the University of Missouri concluded that oral administration of a product containing cetyl myristoleate, glucosamine HCl, MSM, hydrolyzed collagen and other ingredients had beneficial clinical effects on horses with naturally occurring osteoarthritis.

Review of Glucosamine-Containing Oral Joint Supplements: Are They Effective in the Horse? (2006)
In this paper, Weese reports on a number of studies in both humans and horses that conflict regarding the efficacy of glucosamine (some say they work, some say they don’t). He concludes that veterinarians and horse owners who would like to give glucosamine joint supplements should familiarize themselves with nutraceutical products with proven quality and give therapeutic doses (10g orally per day) by carefully reading the label guidelines and ingredients.

Effect of Glucosamine and Chondroitin Sulfate on Mediators of Osteoarthritis (2006)
A study by Neil and others showed that glucosamine significantly reduced a number of mediators of osteoarthritis but chondroitin sulfate did not (at the concentration tested). They mention other studies that showed glucosamine and chondroitin sulfate in combination seem to be more effective than either compound alone.

Double-Blind Study of the Effects of an Oral Supplement Intended to Support Joint Health in Horses with Tarsal Degenerative Joint Disease (2002)
Dr. Hilary Clayton’s group at the College of Veterinary Medicine at Michigan State University demonstrated that horses with hock arthritis showed a significant reduction in gait asymmetry after receiving an oral joint supplement for just two weeks as compared with placebo.

Evidence of the Oral Absorption of Chondroitin Sulfate as Determined by Total Disaccharide Content After Oral and Intravenous Administration to Horses (2001)
Eddington and her co-authors provided the first proof of the bioavailability of chondroitin sulfate in this paper. Their work suggests that the molecule is absorbed after oral administration.

The conclusion I draw from these and other research papers is that there is some evidence that some ingredients in some joint supplements are effective. I recommend working with your veterinarian to develop an overall wellness plan to maintain your horse’s health and soundness as long as possible. This may include FDA-approved pharmaceuticals like the Adequan that you mentioned, and it may also include over-the-counter nutraceuticals as you see fit.

My horse is 3, TB and grew quickly. She has clicking in her joints. She clicks every time she steps in both her back fetlocks. Can you suggest a good supplement for her joints? Is EquinylCM a good one? Any others that you can think of that might be helpful or HARMFUL to a young horse, I don't want to do any damage either! AV, Connecticut

Dear AV:
"Clicking of the joints" is one of the more common questions we get and is a frequent cause for horses to visit our clinic. In most cases it is related to immaturity, lack of conditioning and sometimes size. It is also (rarely) associated with OCD, but not usually. The mechanism of the sounds is the subject of a lot of speculation and some research. Think of the people you know who can crack their knuckles! It's the same thing. If you cause a closed hydraulic system to suddenly expand by stretching the membrane, there isn't enough fluid to fill the space, so oxygen will actually form bubbles and come out of solution and form an air interface with the joint. This is the sound you hear in most cases. It is harmless. One of the other sounds you hear is the cartilages slipping over each other and then falling back into place.

So what to do? Usually, after we've ascertained that there is no cartilage damage, lameness or inflammation, we recommend lots of turn out, conditioning and steady regular work. Any lameness should be explored, but the sounds themselves almost never correlate with injury. Most horses grow out of it, but many continue to click their entire lives.

Jay Merriam DVM
Massachusetts Equine Clinic

We are pleased to have a guest veterinarian provide an answer today. At SmartPak, we realize the importance of staying on top of the latest research, nutritional products and horse health issues, while helping to promote increased involvement of veterinarians in the nutritional management of horses. We have four distinguished members of our SmartPak Equine Veterinary Advisory Council and one of them is Dr. Jay Merriam, DVM. Dr. Merriam was kind enough to answer this entry for us.

I have a horse that had a severe infection in his left hind leg (hock to hoof) back in May, it was doubled in size, we thought we where going to have to put him down, but he pulled out of it. My issue that I have is his leg is still really big (hock to hoof), it does go down some when he is ridden, but it usually stays pretty big must of the time. My vet says it is because the skin stretched so much when it was swollen, so it will always be big from now on. I am just concerned that this is going to cause some issues latter on. Right now my horse is having the winter off, to have some down time, and it is bigger than ever. I was wondering if you have any suggestions or if you think I should have someone else look at it. EC, Vermont

Dear EC,
This sort of injury is a constant source of discomfort to the animal and must be managed in the early stages to prevent long term lameness. There are a lot of things you can do still, depending on a specific diagnosis and treatment plan.

First, think of exercise as "physical therapy" and set out a plan. I think that we need to minimize the scarring and increase the circulation to the area. The best way is a combination of regular exercise (other than turn out which is also good), therapeutic wrapping and support and, if available, Dynamic Compression. We often use and prescribe a Game Ready unit which is a therapeutic wrap with a compression/cold therapy bandage that operates with a pump and bandage system that has been adapted from human athletic therapy. We also in some cases use Regional Limb Perfusion to shrink the swelling and couple that with anti-inflammatories. Every case is different, but we encourage aggressive intervention early on to minimize long term scarring. Good Luck,

Jay Merriam, DVM
Massachusetts Equine Clinic

My horse was just diagnosed with Equine Polysaccharide Storage Myopathy, he is now on Poulin Grain Carb Safe. Can you explain more about this, and how to keep the total carbohydrate level at 12% or below. Thank you. SK, Vermont

Dear SK,

I’m so glad someone finally asked a question about Polysaccharide Storage Myopathy (PSSM or EPSM, depending on whose research you read). Because my own horse has this, I’ve done quite a bit of research on it, and might be able to shed some light on this relatively new disorder in horses for you.

So that everyone knows what we’re talking about, let’s start from the beginning! PSSM is a form of “tying up,” or, exertional rhabdomyolysis, which means “muscle breakdown with exercise.” Some classic examples of this are the working draft horse that gets Sunday off then develops “Monday morning sickness,” the thoroughbred who “ties up” after a race or three-day event, and the Arabian who develops this painful cramping of muscles during an endurance competition. While PSSM is related to these other forms of “tying up,” it is a unique, inherited condition in quarter horses, draft horses and warmbloods that has to do with how sugar (glucose) is taken up and stored in the muscles for energy.

Here’s the current theory: First, PSSM horses are very efficient at pulling glucose out of the bloodstream and putting it into muscles because of heightened insulin sensitivity. Second, because of a mutated gene, the enzyme that transforms glucose into glycogen (the storage form of glucose) is faulty and instead transforms glucose into a different polysaccharide, one that is abnormal and unusable. Therefore managing a PSSM horse involves 1) limiting the amount of sugars and starches he eats, 2) providing fat for energy instead, and 3) keeping the horse’s muscles moving so abnormal polysaccharides don’t build up.

As you’re finding out, performing these three tasks well is not easy! Current recommendations for the maximum amount of sugars and starches range from 10 to 20% of the total daily calories. To achieve this, you’ll probably need to have your hay analyzed (www.DairyOne.com and www.Equi-Analytical.com are good choices), then stick with that one hay source, if possible. If not, you may want to purchase hay cubes in bags, which have a more predictable composition. You’ll also have to be careful allowing your horse access to pasture, as there are certain times when the sugars and starches in grass are very high. Visit www.safergrass.org to learn when grazing is safe and when it’s not. I’m glad to see you’ve pulled your horse off grain (sweet feed, corn, oats, etc.) and are using a low-starch alternative. That’s important, because these horses still need a complete and balanced diet—not just forage—especially if they are being asked to perform. For people who can’t find a low-starch grain in their area, I recommend feeding a ration/forage balancer or multi-vitamin/mineral supplement.

You don’t mention if you’re providing your horse with extra fat, but this is the next step in managing a PSSM horse. Because you’ve taken away much of the sugar and starch they had been using for energy, you need to replace it with another source of energy: fat. Some commercial feeds have added fat, other companies make high-fat products to go along with their feeds, or you can use vegetable fat in a powder or oil to supply these calories. Note: additional Vitamin E (an anti-oxidant) should be fed to horses receiving high fat diets as the increased aerobic metabolism associated with such diets may result in oxidative stress (free radicals). Some experts recommend feeding up to 1 pound of fat a day, but I’ve found a half pound works just fine in my own horse. I feed him four ounces of Cool Calories AM and PM, with SmartE in the morning and MSM in the evening.

Finally, it’s important to provide lots of exercise to PSSM horses. The worst thing you can do is put them in stall! Twelve hours max is the rule. In addition to as much turnout as possible, these horses do best if worked (lunged, ridden, driven) every day. In fact, some experts recommend two shorter bouts of exercise per day! Take your time warming up and cooling down, and if your horse has an extended layoff for any reason, start back very very slowly with him, adding on just a few minutes of additional exercise a day until he’s back at the former level of work.

For those of you reading this who are concerned your horse might have PSSM, here is a list of the other, more subtle signs PSSM horses can have, besides full-blown episodes of “tying up,” which can be as mild as shortened strides or as severe as an inability to move:

• Gait abnormalities
• Mild colic (pawing, rolling, sweating, not eating)
• Muscle wasting or atrophy
• Decrease in level of performance
• Painful and firm back muscles
• Reluctance to collect and engage the hindquarters
• Poor rounding over fences
• Tucked up abdomen
• Difficulty backing
• Difficulty holding up limbs for the farrier
• Muscle trembling
• Muscle weakness
• A “shivers”-like gait

To learn more, visit the University of Minnesota College of Veterinary Medicine Neuromuscular Diagnostic Laboratory website: www.cvm.umn.edu/umec/lab/home.html.