Our American Quarterhorse has HYPP + / -, therefore we monitor her potassium intake. We were wondering if it is safe to use Cocosoya oil as a supplement to her present diet which consists of Oats and Hay. She is also on a diuretic. Prior to our discovery of her being HYPP positive, we did use Cocosoya oil but have eliminated supplements in an attempt to prevent attacks. TC, New York

I have a filly that is 3 years old that I have started riding for about 20-30 minutes a day, not too harsh riding, She is HYPP N/H symptomatic. She has turnout everyday and I exercise her also. My question is she is such a hard keeper I worm her regularly and she gets 2lbs of Equi fuel with 2 scoops of water along with beet pulp and water and she doesn't seem to be gaining weight. She is on the lean side but not showing her ribs. Since she is HYPP I have her on a strict diet since her potassium can not exceed 2%. Can you recommend something? SW, California

Dear TC and SW,

Lucky for you guys I recently attended the North American Veterinary Conference in Orlando, Florida, and spent a whole day in lectures about muscle conditions in horses! In order to devote more time to specific nutritional and management recommendations, I recommend that anyone not familiar with HYPP, or, Hyperkalemic Periodic Paralysis, first read my article: www.smartpakequine.com/hypp.aspx.

At the end of the article, there are specific recommendations from Dr. Sharon Spier, the premier researcher of the disorder:

Avoid high potassium feeds like electrolytes and alfalfa hay

Use low potassium feeds such as grass pasture and whole grains

Feed regular, multiple small meals less than 33g potassium each

Feed a diet between 0.6 – 1.5% total potassium concentration

Provide exercise and/or turnout

Be aware of trigger factors such as fasting or abrupt changes in diet, anesthesia or heavy sedation, trailer rides, stress and others

Medicate with diuretics such as Acetazolamide if necessary

Dr. Spier created the following chart that divides common feedstuffs into high, medium and low potassium feeds. If you have a question about a feed that does not appear on this chart, visit www.equi-analytical.com and click on “Common Feed Profiles.” There you’ll find exact amounts of potassium in almost every hay, forage and grain available. The comparison charts at www.SmartPakEquine.com make comparing levels of potassium in various supplements easy.


High Potassium Feeds

Electrolyte supplements

Molasses

Kelp supplements

Alfalfa hay

Canary grass hay

Orchard grass hay

Soybean meal

Medium Potassium Feeds

Fescue hay

Rice bran

Timothy hay

Coastal Bermuda hay

Kentucky bluegrass hay

Oat hay

Low Potassium Feeds

Pure fats and oils

Beet pulp

Corn, oats or barley

Pasture grass

Wheat

Wheat bran

Soybean hulls

TC, you specifically asked if Cocosoya oil is safe to use in your HYPP mare. According to Dr. Spier, although pure fats and oils fall into the “low potassium feed” category, soybean oil and canola oil do contain enough potassium to be risky. Therefore, since Cocosoya is made with soybean oil, you may want to turn to another source of fat for energy. We did some homework here at SmartPak and discovered that flax is also relatively high in potassium, so you may also want to avoid supplements that contain flax or are flax-based.

I’d like to make one more recommendation to you, TC. If you are struggling to prevent episodes even while she’s on the diuretic Acetazolamide, you may want to switch from oats and hay—which can vary in potassium content with each batch—to a commercial feed with a guaranteed analysis. That way, you always know how much potassium your horse is getting.

Another tip for both of you: while electrolytes must be avoided because of their high potassium content, your horse still needs plain, loose salt, and you can easily provide this in SmartPaks during the summer to replace sweat losses and during the winter to stimulate drinking.

Now for the question from SW: how to put weight on her HYPP filly. One trick to encourage horses to eat more and therefore gain weight is to feed them multiple small meals throughout the day. This works especially well for horses with HYPP, because no one meal should exceed 33grams of potassium (the entire diet should contain between 0.6 – 1.5% total potassium). Pasture also works well for horses with HYPP, because its high water content makes it unlikely horses will consume large amounts of potassium in a short time. And pasture is great for putting weight on horses! Fat (or oil) is another excellent method of getting calories into horses, just be sure to avoid soybeans, canola and flax as sources.

SW, you say you deworm your filly regularly. Have you considered a daily dewormer? When these products first came out, there were claims of 40% increased feed utilization (and therefore weight gain) because worms were killed before they had a chance to penetrate the GI wall and cause inflammation and damage.

I hope these suggestions help. For more information, go to the University of California-Davis website and read articles by Dr. Spier herself: www.vgl.ucdavis.edu/services/hypp.php.

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.

I have a 10 year old 1/2 Percheron 1/2 Quarter Horse mare, and we live in the Midwest outside of Chicago. My mare suffers from severe seasonal allergies - she is the worst in spring/fall. She will cough, have a runny nose & eyes, sometimes has hives, and becomes a little lethargic. I keep her on Cough Free year round. I've tried Tri-Hist to no avail (she will not eat it, and I board, so force-feeding it 2x days is not feasible). Dex works great, but is not show legal - any suggestions on other supplements/medications I can try that are show legal? She does get all day turnout in grass pasture, is inside at night on shavings. She eats alfalfa mix hay and Safe-Choice pellets, along with her SmartPak which includes MVP 4-in-1, Cough Free, and Stress-Dex.

Shame on me for jumping to conclusions, but I’m going to assume from your description that your mare has been diagnosed with “heaves,” or, as it’s being called now, Recurrent Airway Obstruction (RAO). For years the scientific name of heaves was Chronic Obstructive Pulmonary Disease or, COPD, but the name was changed recently because COPD in humans is nonreversible and associated with smoking. RAO, on the other hand, IS reversible, and not generally caused by horses using cigarettes (horses have their vices, but smoking usually isn’t one of them!)

You’ve already mentioned some of the signs of RAO and I’d like to add to your list:

• Coughing (can be dry or productive)
• Labored breathing (can make a horse anxious and sweaty)
• Flared nostrils at rest
• Nasal discharge
• Depression and/or inappetance
• Elevated respiratory rate at rest
• Exercise intolerance or poor performance
• Increased movement of abdomen during breathing (causing the “heave line”)

Veterinarians are able to diagnose heaves without too much trouble using just the history owners give them, a physical examination and bloodwork. However, it’s important to rule out other diseases with similar signs, so specific tests may need to be performed, such as blood gas measurements, endoscopy, chest X-rays, bronchoalveolar lavage (BAL), lung biopsy and lung function testing. And having a baseline or beginning value can help determine if the horse is responding to treatment.

Unfortunately, there is no cure for RAO, but it can be successfully managed. Have you tried taking your mare off hay completely? Organic dust in hay is the main trigger for episodes of “heaves.” If this is not practical—or you can’t find a suitable alternative to replace the fiber in her diet—try soaking the hay for two hours before feeding it.

I’m glad to see that your mare spends at least some time outside on pasture. Is there any way she could be kept outside 24/7? The dust in barns from bedding, traffic in the aisles and even hay that other horses are eating nearby can also trigger episodes. If she must be stalled, avoid straw.

You mention that you have not had any success using antihistamines to treat your mare. This is fairly common. The two categories of medication that DO work are corticosteroids (for example dexamethasone) and bronchodilators (for example clenbuterol). These two drug classes work well together as corticosteroids relieve airway inflammation and bronchodilators relieve airway obstruction. However, they are to be used to treat episodes of RAO, tapering off as improvement is noticed and dietary and environmental management changes are instituted. They are not to be used year-round or in place of removing hay or keeping the horse outside. Ask your veterinarian if the combination of corticosteroids and bronchodilators might be right for your horse, and if giving them through a special equine inhaler would be helpful.

From speaking to other horse owners struggling with RAO, it seems as if the over-the-counter supplements intended to help horses with heaves work in some but not in others. If Cough-Free works for your mare, that’s great! Other choices are plant adaptogens, which restore the body’s natural equilibrium; botanical preparations combining the extracts of several medicinal herbs; and antioxidants, like Vitamin C especially, which may neutralize the oxidative stress associated with RAO.

Dr. Gray,

If a horse is treated for a mild case of EPM, and the treatment is "successful", can the horse make a full recovery or will it always be in their systems to where a possible reoccurrence could happen in the future. Thank you, MLS

Dear M.L.S.,

Equine Protozoal Myeloencephalitis (EPM) is a disease near and dear to my heart, as not one but BOTH my horses developed it. My thoroughbred was treated, made a near 100% recovery, and hasn’t had a single relapse. My quarter horse was treated, did not quite recover his ability to canter, and has relapsed so many times I’ve lost count.

According to Dr. Stephen Reed from The Ohio State University College of Veterinary Medicine, the prognosis for horses with EPM seems to be similar regardless of the treatment used: 60 – 75% of horses improve on standard therapy. Unfortunately, less than 25% of affected horses return to their original function. Standard therapy includes:

Pyrimethamine and a sulfonamide
Ponazuril (commonly known as Marquis)
Nitazoxanide (commonly known as Navigator)

The growing concern, however, is the percentage of horses that relapse days, weeks or even months after treatment. Exactly why horses relapse is unclear, but there are three possible reasons: 1) the parasite that causes the disease, Sarcocystis neurona, came out of a form of hibernation within the horse’s body, 2) a small but persistent focus of infection was never completely killed off, or 3) the horse was re-exposed to the parasite.

To ensure your horse’s chances for success, I recommend a three-pronged approach. First, in addition to the standard therapy listed above, work with your veterinarian to determine if anti-inflammatories such as phenylbutazone (“bute”) or flunixin meglumine (“Banamine”) should be used, if an antioxidant such as Vitamin E might support nervous tissue, and if the B-vitamin folic acid may prevent the deficiency sometimes created with treatment.

Second, continue treatment for as long as your veterinarian advises or until tests on CSF (cerebrospinal fluid) come back negative. Third, follow the currently recommended suggestions for preventing EPM in your horse. There are a number of universities currently studying this disease, including:

University of Kentucky College of Agriculture Department of Veterinary Science Gluck Equine Research Center www.ca.uky.edu/gluck

The Ohio State University College of Veterinary Medicine http://vet.osu.edu/462.htm

The University of California—Davis www.vetmed.ucdavis.edu/ceh

Virginia-Maryland Regional College of Veterinary Medicine www.vetmed.vt.edu

Michigan State University College of Veterinary Medicine www.cvm.msu.edu

Another way to keep up with the latest research on EPM or any other animal health issue is to register with the International Veterinary Information Service (IVIS) found at www.ivis.org. This is a not-for-profit organization established to provide information to veterinarians, veterinary students and animal health professionals worldwide using Internet technology. The IVIS website provides free access to original, up-to-date publications organized in electronic books each edited by highly qualified editors, proceedings of veterinary meetings, short courses, continuing education, and more.

Finally, a site that I visit regularly is the online version of The Horse magazine at www.thehorse.com. Like the veterinary research site above you must register, but registration is free and provides you access to over 10,000 articles on horse health. The Horse is an educational partner of the American Association of Equine Practitioners and has an Advisory Board made up of AAEP members.