• Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph
  • Bailey photograph

Bailey's Polysaccharide Storage Myopathy

Bailey is a 7-year-old AQHA Quarter horse gelding from Helsingborg, Sweden. Bailey was diagnosed with Polysaccharide Storage Myopathy Type 1 (PSSM1) when he was a little over 4 years old. Bailey was bred, born, and broken at a small breeding farm and boarding stable in Sweden. Linn (Bailey’s current owner) was even present the day he was born. She was at the stable grooming another horse when she heard strange noises coming from Bailey’s mom, who was outside in the paddock. Linn went to check on what was wrong and realized that she was giving birth to Bailey. Bailey actually fell into Linn’s arms (his mom refused to lay down to give birth), and a few minutes later the veterinarian and owner arrived. Since that day, Bailey has always been very special to Linn, even before she purchased him from the owner.

When Bailey got older, Linn regular rode Bailey in lessons, she still treated him as if she did—regularly grooming him, spending time letting him graze, and sneaking him treats from time to time. However, although Bailey was safe and compliant while getting ridden, he was not the easiest horse to handle on the ground. Bailey was very stubborn, moody, and sometimes dangerously aggressively towards humans. His moody behavior started when a one and a half years of age, so he was castrated fairly young. However, this didn’t seem to help.

When trying to handle him out of the saddle, Bailey would threaten people by showing his teeth, and sometimes even bite and kicked at them (including his owner at the time). Although Bailey had been fairly easy to break, he hated being saddled, lifting up his hooves for the farrier to put on horseshoes or to clean his feet, getting his hind legs touched, or anyone entering his personal space while he was in his stall. Despite Bailey’s bad behavior and moodiness, Linn really liked him. When Bailey was 6-years old, for various reasons, his owner gave him to Linn, or technically, she “bought” him for 1 dollar.

Bailey’s First Muscle Attack

The first time PSSM symptoms showed was an early summer evening in the paddock while Linn was exercising Bailey. It was the first exercise he’d had in quite some time. Just 3 weeks prior, Bailey was switched from half day turnout to full-time out in the pasture, where he had access to lush green grass. For the first 10-20 minutes of exercise, Bailey acted as he normally would.

Suddenly, just after Linn asked Bailey to canter, it was as if all of Bailey’s energy had been drained---and he refused to take one step further. At first, Linn just assumed he was being lazy. But after leaning forward in her saddle, she realized that his entire body was soaked in sweat. Not like normal sweat, but pouring and dripping sweat from every part of his body. Linn knew that something had to be wrong and decided to try to get him to walk back to the stable, however, she had trouble getting him to move at all and it took her several persistent tries to eventually get him back to the stable.

Linn brought Bailey into the wash stall and gave him a cold bath to try to cool him down. She told her trainer what had occurred, and she immediately called the veterinarian who recommended they bring him into the equine hospital.

Bailey’s Emergency Visit to the Equine Hospital

Bailey was trailered to Evidensia Equine Hospital in Helsingborg, Sweden, which was fortunately only a 10 km (6.2 mile) distance from the stable where Bailey lived. Upon arrival at the hospital, the doctors asked Linn and her trainer questions about his history, performed a physical exam, and took a sample of his blood to run some tests. Bailey had experienced acute exertional rhabdomyolysis (tying-up).

Due to his breed (Quarter Horse), history and clinical signs, the doctors suspected Bailey had PSSM, however they needed to do a muscle biopsy to confirm. The biopsy was sent to the Equine Neuromuscular Diagnostic Laboratory at Michigan State University’s College of Veterinary Medicine. The doctors recommended that Bailey stay at the hospital for observation for the next 5-7 days. Bailey was discharged from the hospital before the results were reported back from the laboratory (which usually takes up to 10 days).

Management of Bailey’s PSSM

Once back at the stable, Linn was advised by her doctor that she needed to start gradually making changes to Bailey’s diet, by adding additional oil and soaking his hay. In two weeks, once Bailey adjusted to the new diet, Linn could start exercising him again. Within the first week of starting Bailey’s new diet, Evidensia Equine Hospital called with the results from Bailey’s muscle biopsy, which came back positive—Bailey had PSSM Type 1. One of the doctors also came out to the farm to check on how Bailey was recovering and to discuss long-term management strategies with Linn for Bailey’s PSSM. Bailey needed a combination of diet, exercise, and management changes to his routine.

  • Feed: Bailey was switched to a high-fat diet, consisting of supplemental corn oil (gradually working up to 5 tablespoons a day), and a pelleted feed with additional protein (Protein Plus).
  • Hay: Bailey needed to receive lots of hay (6-8 kg) that was low on sugar but high on protein. To achieve this, Linn tried soaking Bailey’s hay in water (since this decreases the sugar content), however he stopped eating it. So, Linn and other people at the boarding stable decided to get a hay analysis done on their hay, so that they could find out the exact nutritional content. Once this information was known, Linn was able to control Bailey's sugar intake without needing to soak the hay.
  • Initial Exercise After Tying Up: Once Bailey adjusted to his new diet, Linn could begin reintroducing him back into exercise. His initial exercise schedule consisted of 2-3 weeks of 20-minute hand-walking, followed by 3-5 minutes of walk and trot under saddle. After completing the 3 weeks of under saddle work at the walk and trot, then they could start cantering.
  • Daily Exercise: Once back in regular exercise, Linn was advised that maintaining regular exercise was a really important aspect of managing Bailey’s PSSM. She would need to regularly ride Bailey 6-7 days a week. On days where Linn isn’t able to ride, she’ll exercise Bailey for 5-10 minutes by either letting him run loose in a 30m x 60m paddock (which sometimes may require some “encouragement” through pretending to threaten him with a long whip) or work him on the lunge line. During each of her exercise sessions with Bailey, Linn always tries to be consistent about controlling the duration of Bailey’s exercise, rather than the intensity.
Management: Bailey needed to be constantly moving, and ideally should be on 24/7 turnout in the pasture. However, since it gets very cold in Sweden during the winter months, Bailey is only in the pasture 24/7 during the warm summer months (May through October).

Protein Lumps

So far, with the new diet and management changes, Bailey has not suffered another muscle attack, which has been a little over a year. However, recently over the summer, Linn noticed some irregular lumps underneath Bailey’s belly, in the area where the saddle girth is placed. The lumps appeared almost like insect bites, and at first Linn assumed Baily may had rolled over a fallen bee’s nest somehow while out in the pasture. She called her veterinarian, who consulted with her over the phone, and recommended taking Bailey off the extra protein pellets he received in his diet. Once taking Bailey off of the feed, Linn noticed the lumps getting smaller in just a few days duration. After a week, all of the lumps were gone except for the biggest one, which had reduced to half its original size. Her vet suspected that what Bailey had developed were protein knots, resulting from receiving too much protein in his diet.

About Bailey

Follow Bailey on Instagram at @quarterbailey!

About Evidensia Equine Hospital

Evidensia Equine Hospital is located in Helsingborg, Sweden. In the 1950s the hospital specialized in horses since there was a military cavalry based nearby. In the 60s’ it became a full-service regional hospital for both small and large animals. In 2012, the hospital was bought by Evidensia, who brought in more veterinary specialists from a wide range of veterinary fields.

About the Equine Neuromuscular Diagnostic Laboratory (NMDL)

The Equine Neuromuscular Diagnostic Laboratory (NMDL) is located at Michigan State University’s College of Veterinary Medicine. NMDL specializes in the diagnosis and treatment of muscle disorders in horses, and is the only facility which offers muscle biopsy testing for horses with muscle disorders. The lab has specific procedures for how veterinarians obtain the muscle sample for the biopsy, and require detailed information on the horse’s history and clinical signs to be answered within the submission form. In addition, they also have specific guidelines for how the samples are packaged and shipped to the laboratory.