The unused glucose stored in the liver cell and muscle cells as glycogen (a polymer of glucose). .hs-submit{display: inline-block; color: white;} PSSM: Polysaccharide Storage Myopathy Disorder An autosomal dominant disease caused by mutation in the glycogen synthase 1 (GYS1) gene. To help breeders make informed decisions, AQHA offers a panel test for five genetic diseases: When the test is ordered, AQHA will send a testkit, and the owner will mail the hair sample directlyto the Veterinary Genetics Laboratory at the University of California-Davis for testing. Valberg SJ. More Quarter Horses are affected by PSSM than any other breed, but they are less likely to suffer from muscle atrophy. There are two types of EPSSM: The most common signs of PSSM in horses are tying up like symptoms due to excessive deposition of glycogen in the muscle cells. While Quarter Horses have a higher incidence of exertional rhabdomyolysis, they are less likely to suffer from muscle atrophy than Draught or Warmblood horses. Insulin can further worsen PSSM because it causes the GYS1 gene to produce even more glycogen. Horses with Type 1 PSSM can be identified by genetic testing. Treatment of polysaccharide storage myopathy. PSSM is caused by a build-up of glycogen in the muscles, which can be caused by a genetic mutation. 2009 Jul;41(6):597-601. If necessary, caloric intake should be reduced by using a grazing muzzle during turn-out, feeding hay with a low nonstructural carbohydrate content (NSC) at 1 to 1.5% of body weight, providing a low calorie ration balancer and gradually introducing daily exercise. The urine in such horses is often coffee coloured, due to muscle proteins being released into the bloodstream and passed into the urine. Some horses make and store abnormal muscle glycogen (a form of energy) and cannot tolerate dietary starches and sugars. Since many horses with PSSM are easy keepers, the first dietary criterion is to remove high starch ingredients. 784 Wilson Road, D202 Thousands of horses have been identified with tying-up associated with polysaccharide accumulation in muscles. Some weanlings and yearlings can develop muscle stiffness with daily activities and difficulty standing. Shortened stride. .hs-error-msg{color: #29353d} PSSM is a muscle disorder that affects horses. In contrast, a 4% NSC Blue Grama hay would provide 13.5 MCal/day which would allow a reasonable addition of 4.5 MCal of fat per day (538 ml of vegetable oil). . Quarter Horse Bloodlines to Avoid. Here they can perform DNA blood or hair tests. Genetic testing There is no cure for PSSM, but there are treatments that can help manage the disease and improve the horses quality of life. AQHA Stallions An Obvious Kid - HYPP N/H n/n for HERDA, GBED, PSSM, MH http://www.allbreedpedigree.com/an+obvious+kid2 A Spark of Sunshine - n/n for 5-panel 2009 Mar;179(3):336-47. Equine Vet J. Some horses will try pawing and rolling immediately after exercise. Sections of muscle are evaluated with a number of special stains. The mutation in the GYS1 gene causes unregulated synthesis of glycogen, which results in excessive sugar in muscle cells. Michigan State University Continued research into PSSM in Quarter Horses resulted in the discovery of a genetic mutation in the glycogen synthase 1 gene in this herd of research horses. HYPP was seen in Impressives sons and daughters because to be expressed, the disease does not require two copies of the defective gene. Equine Vet J. Once cool, the horse may have free access to water. The effects of these genetic diseases are wide-ranging, from mild and manageable to severe and terminal. For assistance in formulating a diet appropriate for your horse with PSSM, contact our team of equine nutritionists to receive customized recommendations. Authors: Molly McCue, DVM,Nichol Schultz, DVM formerly with the University of Minnesota,Stephanie Valberg, DVM, former professor, U of MN College of Veterinary Science. Commercial genetic testing for type 2 polysaccharide storage myopathy and myofibrillar myopathy does not correspond to a histopathological diagnosis. At this time, aside from PSSM1, there is not a genetic test for other forms of PSSM. Few, In the typical system, excess glucose stirred in the liver cell and muscle cell as glycogen. CanStockPhoto/LByst. When proper diet and exercise routines are followed, researchers found that all horses improved, and more than 75 percent of horses stopped tying-up. Description: The mutation results in a malfunctioning calcium-release channel of the sarcoplasmic reticulum in skeletal muscle. 2007 Nov;39(6):567-75. The disease is characterized by muscular weakness, lethargy, reluctant to rise, muscle damage, increase serum creatinine, and reduced performance.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[468,60],'thevetexpert_com-box-3','ezslot_8',112,'0','0'])};__ez_fad_position('div-gpt-ad-thevetexpert_com-box-3-0'); In the typical system, excess glucose stirred in the liver cell and muscle cell as glycogen. Annandale EJ, Valberg SJ, Essen Gustavsson B The effect of submaximal exercise on adenine nucleotide concentrations in skeletal muscle fibers of horses with polysaccharide storage Myopathy Am J Vet Res 2005;66:839-845. Equine Veterinary Journal Suppl.36 2006:340-344. At least three weeks of walk and trot should precede work at a canter. Electrolytes are minerals that play an important role in muscle function. Neuromuscular Disorders. .hs-main-font-element{color: #29353d} Rest: For chronic cases, prolonged rest after an episode appears to be counterproductive and predisposes PSSM1 horses to further episodes of muscle pain. Breeds Affected: Animal Genetics offers DNA testing and detection for markers identifying horses that could suffer from PSSM in American Paint horses, Appaloosas, Draft Breeds, Quarter horses (horse with quarter horse blood) and Warmbloods. Diagnosis of the GYS1 gene by in some reputed Equine Laboratory in the United States and Europe like Michigan University Equine Neuromuscular Diagnostic Laboratory, University of California, Laboklin in Europe. Once inside the cell the muscles of PSSM horses make much more glycogen than a normal horse due to a mutated (overactive) enzyme called glycogen synthase. It was first recognized in horses with Quarter Horse bloodlines such as Quarter Horses, American Paint Horses and Appaloosas and in draft and warmblood breeds with continental European bloodlines (Belgian and Percheron, for example). PSSM occurs primarily in horses with Quarter Horse bloodlines, but can also occur in Warmbloods and Draft breeds. When horses stop moving they may stretch out as if to urinate. Equine Vet J 1999;31:43-47. The mutation in the PPIB gene results in defective collagen that causes the outer layer of the skin to split from the layer underneath. DeLaCorte FD, Valberg SJ, MacLeay JM and Mickelson JR. Developmental onset of polysaccharide storage myopathy in 4 Quarter Horse foals. The risk of producing an affected offspring when breeding a horse with PSSM1 is much higher because it is a dominant disease. Ribeiro W, Valberg SJ, Pagan JD and Essen Gustavsson B. The muscle biopsy technique identified an apparent glycogen storage disease and the terms PSSM or EPSM and EPSSM were used to describe the condition. Learn more about the five equine diseases it covers HYPP, PSSM1, MH, GBED and HERDA. In an easy keeping horse, when you add fat the cheapest way to do so is to add oil or a solid fat supplement onto a pelleted ration balancer that provides enough energy. Stephanie Valberg, DVM, PhD, DACVIMMary Anne McPhail Dressage Chair in Equine Sports Medicine, Department of Large Animal Clinical Sciences Type 2 polysaccharide storage myopathy in Quarter Horses is a novel glycogen storage disease causing exertional rhabdomyolysis. Fat can be a great alternative. Weanlings can be fed 6.5 lbs of Re-Leve and mixed grass/alfalfa hay (8 lbs/day). Rules The mutation causes this glycogen synthase enzyme to be overactive, increased in activity especially in the presence of insulin resulting in constant production of glycogen. Research conducted at the University of Minnesota has identified two types of PSSM. Genomics 2008 May;91(5):458-66. This can cause episodes of muscle stiffness and pain after exercise, also known as tying up or exertional rhabdomyolysis. Feeding a low NSC hay of 4% provides room to add an adequate amount of fat to the diet of easy keepers without exceeding the daily caloric requirement and inducing excessive weight gain. Type 1 PSSM is the form of PSSM caused by the genetic mutation in the glycogen synthase 1 () gene. J Vet Int Med 1998;12:173-177. The management of Equine Polysaccharide Storage Myopathy includes the combination of diet, exercise, and metabolism of carbohydrates within the cells. These areas are slow to heal, and many horses with HERDA are euthanized due to slow-healing injuries. Related:The Not-So-Fab Four: Diseases Resulting in Hind Limb Gait Deficits. Some horses will try pawing and rolling immediately after exercise. For chronic cases, prolonged rest after an episode appears to be counterproductive and predisposes PSSM horses to further episodes of muscle pain. This enhances glucose utilization, and improves energy metabolism in skeletal muscle. Valberg SJ. She is an established authority in the pet blogging community, and her blog, "Paws and Claws," has been featured in numerous publications. If only the diet is changed, we found that approximately 50% of horses improve. Inheritance of PSSM1: Each horse has two copies of every gene (genotype), one inherited from the dam and one from the sire. PSSM is caused by an abnormal build-up of glycogen in the muscle cells. You should consider a muscle biopsy for horses with muscle pain if they test negative for PSSM 1. The NSC component of rice bran can vary if the manufacturing process is not careful to exclude the white rice grain. When designing a feeding program for horses with PSSM, it is important to limit energy sources containing high starch ingredients such as sweet feed, corn, wheat, oats, barley, and molasses. Rarely, episodes of muscle pain and stiffness can be quite severe, resulting in a horse being unable to stand and being uncomfortable even when lying down. Most PSSM1 horses are calm and not easily stressed, however, if stress is a precipitating fact, stressful environmental elements should be minimized. This is also a good diet for young growing horses with PSSM1. Collapse. Horses should begin small paddock turnout as soon as reluctance to move has stopped. Valberg SJ, MacLeay JM, Billstrom JA, Hower-Moritz MA and Mickelson JR. Skeletal muscle metabolic response to exercise in horses with polysaccharide storage myopathy. Its likely an old genetic mutation that occurred prior to the foundation of most modern horse breeds. Quarter Horse-related breeds with type 2 PSSM also have abnormal glycogen storage, and, although the cause of this myopathy is unknown, they are fed similarly. There is no cure for PSSM, but it can often be managed successfully. Genetic testing is also part of the AQHA 5 panel genetic test and is performed at the Veterinary genetics Laboratory at the University of California Davis. Polysaccharide Storage Myopathy, or PSSM, is a type of muscle disease that affects horses with Quarter Horse bloodlines. You can manage PSSM in your horse by providing an alternate energy source to sugar. 2020. Breeding and foal care, , CanStockPhoto/Vanell. You must avoid the complete rest of your horse. The University of Minnesota is an equal opportunity educator and employer. If you feed a product like ReLeve or Ultium you usually need at least 4 lbs to achieve a balanced diet and this may be too many calories in lightly worked overweight horses. This is because diet, exercise regimes and the many interactions between genes can vary from breed to breed. Your veterinarian can help you to select the best diet for your horse. Over 60% of Percherons and 90% of Belgian Draft horses are affected. Concurrent Gastrointestinal or respiratory infections. Am J Vet Res 2003;64:1319-1327. Many of his offspring followed in his success, with 36 becoming AQHA champions. He was powerful and fast, which led him to be a champion in the show ring. 2011 Dec;95(6):798-807. This is different from diseases such as HERDA and GBED, which are inherited in a recessive fashion, where 2 copies of the mutant gene are required for disease. Many horses with this condition are happy trail horses, successful pleasure horses, and useful ranch horses. Hunt LM, Valberg SJ, Steffenhagen K and McCue ME. Dranchak, PK, Leiper FC, Valberg SJ, Piercy RP, Carling DC, Molly E. McCue, ME Mickelson JR. Biochemical and genetic evaluation of the role of AMP activated protein kinase in polysaccharide storage myopathy in Quarter Horses. Two types of PSSM have been identified, PSSM1 and PSSM2. J Am Vet Med 2009 Jan 1;234(1):120-5. Rather than provide dietary fat to an overweight horse, fasting for 6 h prior to exercise can be used to elevate plasma free fatty acids prior to exercise and alleviate any restrictions in energy metabolism in muscle. There are currently no scientifically verified DNA tests for PSSM2, but a muscle biopsy can be performed for diagnosis. A glycogen synthase 1 mutation associated with equine polysaccharide storage myopathy and exertional rhabdomyolysis occurs in a variety of UK breeds. Researchers have not yet determined what causes PSSM Type 2. PSSM horses, however, will always be predisposed to this condition if their diet or exercise schedule is disrupted. Tying-up also occurs in other breeds of horses such as Thoroughbreds and Standardbreds, but this form of tying-up has a different cause. When there is an imbalance of electrolytes, it can disrupt muscle function and lead to tying-up. Genetic testing determined that some horses with PSSM had a specific mutation in GYS1 (PSSM Type 1), while others did not have the mutation in the GYS1 gene (PSSM Type 2). PSSM also occurs in other breeds including Drafts, Draft crossbreeds, and Warmbloods. Note the lack of a uniform texture in the PSSM1 biopsy. Since it is an autosomal dominant trait, only one copy of the mutation is needed for a horse to be affected. 2008 Sep-Oct;22(5):1228-33. The Releve Concentrate works well for PSSM1 in moderate to heavy work that require at least 4 lbs of concentrate a day. , Polysaccharide Storage Myopathy (PSSM) is a chronic muscular condition in horses that comes under the broader heading of "tying up," or exertional rhabdomyolysis. Get the monthly horse newsletter by email. Description: The mutation in the sodium channel gene causes dysfunction in a specific type of sodium ion channel. Who Are the Members of My Animal's Veterinary Health Team? PSSM is a disease that causes an abnormal accumulation of glycogen, the form of sugar stored in the muscle. The GYS1 gene carries the instruction for the enzyme glycogen synthase. Suitable oils include soybean, corn, safflower, canola, flaxseed, linseed, fish, peanut and coconut. Both tests are done at the University of Minnesota. Photo: Wikimedia Commons. Feed only hay until symptoms subside. Stanley RL, McCue ME, Valberg SJ, Mickelson JR , Mayhew IG, McGowan C, Hahn CN ,. Pinched skin will normally spring back and saliva should be wet, not tacky. An old theory about tying-up is that it is due to too much lactic acid in the muscle. This excess sugar causes mild to severe muscle cramps, sore muscles and/or muscle weakness. International Conference on Equine Exercise Physiology Equine Vet J Suppl. However, with proper management and care, horses with PSSM can live long and healthy lives. 1995;228-230. PSSM also affects many other breeds. Turn out is very beneficial for PSSM1 horses as they get regular exercise during turn out, however consider the sugar content of the pasture when designing a diet. Insulin is a hormone that controls a horses blood sugar level. Polysaccharide storage myopathy or PSSM is a muscle disease that occurs primarily in horses with Quarter Horse bloodlines such as Quarter Horses, Paint Horses, and Appaloosas. Description: The mutation of the GBE1 gene reduces the function of the glycogen branching enzyme so that cardiac and skeletal muscle, the liver and the brain cannot store and mobilize glycogen. formId: "d01f22bb-5b4c-4eb3-9a24-219a6869b198" It's likely an old genetic mutation that occurred prior to the foundation of most modern horse breeds. Horses that test positive for P2, P3, P4, P8, or K1 should receive dietary supplementation with complete . In Vivo Evaluation of Lag Screw Fixation of Sacroiliac Luxation/Fracture, Use of a Novel Imaging System as a Non-Invasive Diagnostic Tool for Evaluating Feline Iris Melanocytic Tumors, Instinct: New Electronic Medical Records System. The routine exercise includes walk, lunging, riding, and turnout. This build-up of glycogen interferes with the muscle cells ability to contract and relax, which can lead to muscle stiffness, cramping, and weakness. Under saddle, affected horses may be reluctant to go forward or collect. If they become ill from other causes, they may again develop clinical signs again. Enhanced glucose uptake in horses with polysaccharide storage myopathy (PSSM1). PSSM in horses or Polysaccharide storage myopathy is a severe and inheritable glycogen storage disease characterized by muscle damage, stiffness, reluctance to move, and severe colic. Muscle glycogen concentrations in affected horses are up to four times greater than in normal horses. Even 10 min of exercise has been shown to be extremely beneficial in reducing muscle damage with exercise. Because of the pain and stiffness, horses are reluctant to move. The clinical signs of a PSSM episode are typically associated with tying-up. The condition is known as exertional Rhabdomyolysis. Thus, sugar from a horses diet can stimulate an insulin response. This occurs more often if they have a simultaneous infection such as pneumonia or diarrhea. In some cases, sedatives, analgesics, muscle relaxants, and non-steroidal anti-inflammatory drugs (NSAIDs) may be used to provide pain relief, especially for short periods after active episodes of tying up.