Learn how nutrition, supplements, exercise and other management practices can help with Tying Up, PSSM and HYPP in horses.

1. Understanding Equine
Muscle Disorders
Lydia F. Gray, DVM, MA
Medical Director/Staff Veterinarian
Jessica Normand
Senior Director – SmartSupplements™
May 16, 2012

2. Your Presenters
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3. Agenda
• Overview of Muscle Disorders
• Tying Up
• PSSM
• HYPP
• Questions & Answers
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4. Overview of Muscle Disorders
• According to the AAEP, as of February 2012 tests for mutations in
single genes are currently available for 12 diseases in horses.
Three of them are muscle-related:
1. HYPP
2. Type I PSSM
3. Malignant Hyperthermia (not discussed in this webinar)
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5. Exertional Rhabdomyolysis aka “Tying Up”
What Is It?
• Muscle stiffness and pain after exercise
• Two types:
o Sporadic Tying Up
 Due to a temporary problem in muscle cells caused by fatigue, heat
exhaustion or electrolyte imbalance
 Can occur in any breed
o Recurrent Tying Up
 An inherited problem with the way muscle cells use calcium
 Is mainly seen in Thoroughbreds, Arabians and Standardbreds
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6. Tying Up:
Sporadic Exertional Rhabdomyolysis (SER)
What Is It?
• First-time or occasional episodes of tying up
• No age, breed, gender or discipline predilection
• Temporary imbalance, no intrinsic muscle defect
• Triggers include:
o Exercise beyond fitness level
o Injury from repetitive motion
o Heat exhaustion
o Dietary imbalances
o Electrolyte imbalances
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7. Tying Up:
Sporadic Exertional Rhabdomyolysis (SER)
What does it look like?
• Signs:
• Muscle stiffness
• Short strides
• Shifting hind limb lameness
• Elevated heart and respiratory rates
• Sweating
• Firm & painful hindquarter muscles
• Reluctance to move that lasts for several hours
• Diagnosis:
o History, risk factors, classic signs
o Blood work
o Urinalysis
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8. Tying Up:
Sporadic Exertional Rhabdomyolysis (SER)
How is it treated/managed?
• Medical Treatment:
o DO NOT MOVE HORSE!
o Pain relievers: bute, Banamine®
o Tranquilizers (for anxiety)
o Fluids: oral or intravenous
o Dantrolene for muscle relaxant, methocarbamol
o Do not administer diuretics (i.e. Lasix)
• Management:
o Stall rest and hay only for a few days
o Gradually increase time and size of turnout, add hand walking
o Resume training when blood work is within normal limits
o Ensure diet is complete and balanced
o Consider supplements: Electrolytes, Vitamin E, possibly Selenium
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9. Tying Up:
Recurrent Exertional Rhabdomyolysis (RER)
What is it?
• Tying up that occurs repeatedly
• Primarily seen in Thoroughbreds, Standardbreds and Arabians
o Classic example is two-year-old nervous filly in race training
• Caused by inherited abnormal regulation of intracellular calcium
• Can be triggered by exercise, stress or combination of both
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10. Tying Up:
Recurrent Exertional Rhabdomyolysis (RER)
What does it look like?
• Signs:
o Muscle stiffness
o Short strides
o Shifting hind limb lameness
o Elevated heart and respiratory rates
o Sweating
o Firm & painful hindquarter muscles
o Reluctance to move that lasts for several hours
• Diagnosis: • Additional tests
o History, risk factors, classic clinical signs • Exercise challenge test
o Blood work • Muscle biopsy
o Urinalysis
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11. Tying Up:
Recurrent Exertional Rhabdomyolysis (RER)
How is it treated/managed?
• Medical Treatment:
o DO NOT MOVE HORSE!
o Pain relievers: bute, Banamine®
o Tranquilizers (for anxiety)
o Fluids: oral or intravenous
o Dantrolene for muscle relaxant, methocarbamol
o DO NOT ADMINISTER DIURETICS (i.e. Lasix)
• Management:
o Resume training gradually but immediately (no stall rest)
o Diet change: decrease sugars/starches and increase fat
o Consider supplements: Electrolytes, Vitamin E, Chromium, possibly Selenium
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12. Tying Up:
Recurrent Exertional Rhabdomyolysis (RER)
• Additional Management Strategies for Racing Thoroughbreds
o Avoid excess stress, if possible
 Stall in quiet area of barn
 Train when facility least busy
 Avoid “exciting” training regimens
 Tranquilize before training
 Give dantrolene before exercise
o Consistent exercise program
 Provide daily turnout
 Exercise daily (no days off)
 Avoid stall rest and lay-ups
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13. Supplements to Consider for Tying Up
Electrolytes
Specialty Muscle
Formulas
Chromium Vitamin E, Selenium,
Magnesium
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14. Polysaccharide Storage Myopathy (PSSM)
What is it?
• aka EPSM or EPSSM (Equine Polysaccharide Storage Myopathy)
• A dysfunction in the way muscles store glycogen, the storage form of glucose
(sugar)
• An inherited condition found primarily in Quarter Horses, draft horses,
warmbloods and warmblood crosses
• Two types now recognized (Type I and Type II)
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15. Polysaccharide Storage Myopathy (PSSM)
What does it look like?
In Quarter Horses (usually Type I)
Typically occur a few minutes after the onset of exercise:
•Stiffness, reluctance to move
•Firm, painful muscles
•Elevated heart and respiratory rates
•Anxiety and excessive sweating
•Posturing to urinate, stretching out
•Muscle twitches
•Pawing, rolling
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16. Polysaccharide Storage Myopathy (PSSM)
What does it look like?
In draft horses and warmbloods (usually Type II):
•Difficulty picking up feet, holding up limbs and backing
•A “shivers-like” gait
•Loss of muscle mass
•Tucked up abdomen
•Difficulty collecting
•Reluctance to engage the hindquarters
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17. Polysaccharide Storage Myopathy (PSSM)
How is it treated/managed?
• Treat the acute episode as exertional rhabdomyolysis then:
o Diet:
 Reduce sugars and starches
 Increase fat
 Provide appropriate Vitamin E and possibly Selenium
o Exercise:
 Turnout as much as possible – no more than 12 hours in stall
 Provide daily, controlled exercise
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18. Polysaccharide Storage Myopathy (PSSM)
Credit: University of Minnesota Equine Center, College of Veterinary
Medicine, Neuromuscular Diagnostic Laboratory
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19. Supplements to Consider for PSSM
Pure Fat Vitamin E, Selenium,
Magnesium
Adaptogens
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20. Hyperkalemic Periodic Paralysis (HYPP)
What is it?
• Dominant inherited trait affecting Quarter Horses, Paints, Appaloosas and
Quarter Horse crosses worldwide
• Caused by a defect in the skeletal muscle sodium channel
• 1992: It was publicly linked to a popular Quarter Horse sire named
Impressive
• 1996: AQHA officially recognized HYPP as a genetic defect or undesirable
trait
• 1998: Mandatory testing began for foals descending from Impressive
• 2007: Foals born this year or later that test homozygous will not be eligible
for registration
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21. Hyperkalemic Periodic Paralysis (HYPP)
What does it look like?
• Intermittent signs first appear at 2-3 years of age
• Episodes begin with muscle rigidity and possible third eyelid prolapse
• Horse then develops sweating and muscle tremors, especially in the flanks,
neck and shoulders; may spread throughout body
• Horse may develop severe cramping or muscular weakness
• Horses generally remain standing during mild attacks
• During severe attacks, horse may sway, stagger, dog sit or lie down
• Horse may have elevated heart and respiratory rates, anxiety
• Episodes usually last between 15-60 minutes
• Death may occur due to respiratory distress
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22. Hyperkalemic Periodic Paralysis (HYPP)
How is it managed?
• Limit Potassium (K) in the diet!
o Aim for 0.6-1.5% of total diet
o No more than 33g of K per meal
• Dietary triggers to avoid:
o Alfalfa
o Molasses
o Electrolyte supplements
o Kelp supplements
• Pasture turnout is ideal because of high water content in grass (and exercise)
• Feed later cuts of Timothy or Coastal Bermuda Hay (least amount of potassium)
• Beet pulp and cereal grains like oats are also a good choice
• Have grass and hay analyzed for potassium content
• Or, provide a commercially available complete feed
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23. Hyperkalemic Periodic Paralysis (HYPP)
High Potassium Feeds Medium Potassium Feeds Low Potassium Feeds
(>2% K) (1-2% K) (<1% K)
Electrolyte Supplements Rice Bran Pure Fats, Oils
Molasses Timothy Hay Beet Pulp
Kelp Supplements Coastal Bermuda Hay Corn, Oats, Barley
Alfalfa Hay Kentucky Bluegrass Hay Wheat
Canary Grass Hay Oat Hay Wheat Bran
Orchard Grass Hay Fescue Hay Soybean Hulls
Soybean Meal -- (Flax Seed)
Credit: Dr. Sharon Spier, AAEP Annual Convention 23

24. Hyperkalemic Periodic Paralysis (HYPP)
How is it treated?
• Administer acetazolamide orally every 8-12 hours as a
preventative
• Immediate treatment during an episode may include:
o Owner Options:
 Light exercise
 Grain or corn syrup
o Veterinary Options:
 Acetazolamide
 Calcium Gluconate
 Dextrose
 Epinephrine
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25. Supplements to Consider for HYPP
Pure Salt Antioxidants
Adaptogens Appropriate Muscle
Formulas
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26. Questions & Answers
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27. Questions
1. What type of feed/supplements are good for horses with PSSM?
2. What are the breeding concerns when contemplating breeding a EPSM horse?
3. A client believes these to be signs of PSSM in her horse: Droopy lip, glazed
eyes, frequent urination. These are new signs to me. Can you please confirm?
No other typical weakness is evident. Thank you!
4. My QH gelding is HYPP N/H. What is the best feed and exercise regimen to
keep him healthy?
5. Can you please suggest management best practices for horses with PSSM that
are also overweight?
6. I've been using DMG for my HYPP N/H mare for a few months. I've seen a
significant difference in her comfort, especially in her sensitivity to
touch/being cold backed. Is it safe to give my mare DMG long-term?
7. Is SmartBug Off safe to use for my HYPP horse? Currently he is on MSM,
Cosequin, SmartGut & Quietex. Thanks!
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28. Questions
1. Are muscle disorders genetic? What supplements support good muscle
development if a horse has developed a problem around age 7?
2. Are certain horse stretches helpful for horses with PSSM? Is there harm in
feeding a PSSM horse a high protein diet? How does a diagnosis of mild PSSM
(in 5 year old warmblood) affect the horse's life expectancy/quality of life if
managed well? Is there any long-term damage?
3. My recently purchased Arabian horse just tied up for the first time the other
day. I didn't really know of this condition until it happened. I saw 5
supplements to help this. Wondering what's best to help prevent this from
happening again?
4. Is tying up chronic? or random?
5. My horse tied up this past spring. I am still trying to determine why. She is
not the nervous type. I feed Omolene 100. I do not use supplements. Could it
come from the extra protein in the spring grass? Bloodwork showed enzyme
level of 6000.
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29. Questions
1. Could you please explain any muscle changes that occur in older horses and
how to work with those changes in my riding? My horse is 19 years old.
2. Can you please talk about EPSM and feeding to keep those horses safe that
haven't been tested but are prone to developing symptoms of this disease?
3. Can you explain why an illness, particularly with a fever, causes PSSM which is
otherwise well controlled, to flare up?
4. How does the age of a horse relate to muscle disorder possibilities?
5. My horse has a lack of muscle tone on either side of his hip in the thigh area.
Can this be due purely from a lack of work? He moves great and isn't lame
but lacks muscle tone in this area.
6. Is there a way to determine in advance if a horse is prone to a muscle
disorder?
7. I have a 9 yr old mare that ties up (seems to be more stress related). She has
been tested for PSSM and was negative. I have changed her diet to no alfalfa,
low carb/sugar, I add vit e and se, but still see this happening. Any advice?
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30. Questions
20. I have 4 yo Perch/Paint cross that is 17hh. He has developed a upward fixating
patella. Is this a result of his large size and a growing spurt? or is it an early sign
of PSSM (since he is a draftx). Should I change his diet?
21. How to treat a horse that is tying up on the road. How long do you need to
keep the horse stalled after the incident?
22. Does PSSM have significant varying degrees of severity and does it wax and
wane in an individual horse?
23. How does this correlate with Cushings?
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31. Thank you for attending our Webinar!
Have additional questions?
Please visit us at SmartPak.com
Call us at 1-800-461-8898
or
Email us at CustomerCare@SmartPak.com
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