Topics

Breeding and Reproduction

Horse breeding from planning through foal care

Hoof Care

Prevention and treatment for problems of the equine foot

Nutrition

Proper feeding practices for foals, adult horses, and older horses

Welfare and Industry

Discussions about the welfare of our equine friends

Diseases and Conditions

Horse-heath-problem risk factors, prevention, diagnosis, and treatment

Horse Care

How to care for the basic health needs of horses

Sports Medicine

All aspects of caring for performance horses

All Topics

Farm and Barn

Design and maintain a healthy horse operation

Lameness

Prevention, diagnosis, and treatment of leg lameness

Vet and Professional

News and issues for equine health professionals
Magazine
Cover Story

Supporting Your Horse's Immune System

What does it take to optimize the equine immune response and fight off disease?

Also in this Issue

Rhodococcus equi Pneumonia: Rethinking Treatment to Fight Resistance
Skill, Science, and Sensitivity: Unpacking Horse Training Misconceptions
Rehabilitating the Neurologic EPM Horse
Building a Balanced Diet for Your Mare and Foal
Joint Health Matters: Top Therapies for a Successful Season
The Abscess Ruptured, But My Horse is Still Lame. Now What?
Understanding Horse Aggression
Digital Edition

Give a Gift

Subscribe

Manage My Subscription
News

Latest News

Large Colon Volvulus in the Postpartum Mare

Equine Innovators: Improving Joint Health in Horses With Orthobiologics

A Case of Persistent Pastern Dermatitis

Deciphering Multilimb Lameness in Horses

Equine Hoof Care Teams at Work

Smart Manure Management for Small Horse Farms

More News

Disease Alerts

EDCC Health Watch

Event Coverage

2024 AAEP Convention
2024 EquiSUMMIT
2024 Olympics
Features

Latest Features

Managing Your Performance Horse’s Joints

April 9, 2025

Understanding, Recognizing, and Managing Pain in Horses

March 20, 2025

Additional Features

How Much Does It Cost to Own a Horse?

Dealing With Equine Colic: Here are 33 Do’s and Don’ts

Promoting Longevity in Performance Horses

Everything You Need to Know About Laminitis in Horses

How to Feed Your Horse

All Features
Q&As

Latest Q&A

Smart Manure Management for Small Horse Farms

April 15, 2025

Equine Nutrition FAQ Series

Sponsored by Purina Animal Nutrition

Learn More

Q&As

Equine Behavior

Our animal behavior experts field your questions about why your horse does XYZ.

Horse Nutrition

Equine nutritionists respond to queries about forage, grain, supplements, and other related topics.

Performance Horse Health

Veterinarians and researchers tackle questions about equine athletes.
Visuals

Featured Media:

Wound Care Strategies for Healing Wounds in Horses

Tips for Feeding Senior Horses

Quick Links

Webcasts

Infographics

Slideshows
Podcasts

Featured Podcasts

Equine Innovators: Improving Joint Health in Horses With Orthobiologics

Keeping Horses With Joint Disease Fit

Podcasts

Ask 'TheHorse' Live

The Horse’s experts answer your questions during a monthly live audio event.

Equine Innovators

Join us as we interview leading equine researchers from the University of Kentucky.

All Podcasts
Free Reports

Fact Sheet: Pituitary Pars Intermedia Dysfunction (PPID)

Fact Sheet: Equine Protozoal Myeloencephalitis (EPM) in Horses

Free Reports:

View All Free Reports

Quick referenced of horse conditions, diseases and health topics

Forms

Checklists and identification forms for horse owners
Tools

Normal Horse Vital Signs and Health Indicators

Mare Gestation Calculator

Adult Horse Weight Calculator

Additional Resources

Event Calendar
Horse Health Glossary
Get-A-DVM
New Products
Polls
TheHorse.com en Español
StableManagement.com

Polysaccharide Storage Myopathy (PSSM)

Subcategories:

None

Managing Equine Genetic Disorders with Nutrition

Erica Larson June 6, 2012

Managing diet can help alleviate signs of some equine genetic disorders, such as PSSM and HYPP.

AQHA Offers Genetic Disease Panel Test

Erica Larson February 6, 2012

The test will screen for five potentially fatal genetic diseases often found in Quarter Horses.

feeding weanling horses; feeding weanlings

What’s In Your Horse’s DNA?

Marie Rosenthal, MS December 1, 2010

Geneticists have created tools and tests that help horse breeders select for healthy foals. Furthermore, access to the equine genome means scientists can examine common diseases and conditions and find ways to prevent (and one day treat) them.

Fatty Acid Triheptanoin Comes Up Short for Horses with PSSM

Stacey Oke, DVM, MSc April 3, 2010

Triheptanoin does not appear to be a good fat supplement for polysaccharide storage myopathy (PSSM) horses.

PSSM Genetic Mutation Reported in Some UK Horse Breeds

Stacey Oke, DVM, MSc June 18, 2009

Collaborative efforts between researchers on both sides of the Atlantic have identified that a genetic mutation in enzyme glycogen synthase 1 (GYS1) is an important cause of polysaccharide storage myopathy (PSSM, a form of

Effects of Hay Carbs on PSSM Horses Examined

Kathryn Watts, BS June 8, 2009

The study group’s objectives were to determine if there is a difference in blood glucose and insulin response to feeding hay types with varying water soluble sugar and starch (NSC) content between horses with PSSM and control horses.

UK Incidence of Polysaccharide Storage Myopathy Reported

Stacey Oke, DVM, MSc May 21, 2009

Not only is polysaccharide storage myopathy (PSSM) a common and important muscular disorder in various horse breeds in the United States, but according to a recent research report, it is also a common diagnosis in horses in the Unite

Polysaccharide Storage Myopathy (PSSM): A Genetic Diagnosis, AAEP 2008

Nancy S. Loving, DVM March 13, 2009

Polysaccharide storage myopathy (PSSM) is a metabolic muscle problem found in at least 20 breeds, including Quarter Horses, Paints, Appaloosas, and drafts. An affected horse suffers bouts of exertional rhabdomyolysis (tying-up), muscle tremors

Polysaccharide Storage Myopathy (PSSM): Search for Underlying Causes Continues

Stacey Oke, DVM, MSc October 6, 2008

Despite having recently identified a genetic defect that results in polysaccharide storage myopathy (PSSM) in many horses, the underlying cause of PSSM remains to be determined in others.

Genetic Mutation for Polysaccharide Storage Myopathy Widespread

Stacey Oke, DVM, MSc September 20, 2008

Veterinary researchers from the University of Minnesota have identified a gene potentially responsible for polysaccharide storage myopathy (PSSM) in Quarter Horses and, in doing so, they uncovered a number of research leads to pursue. In a

Diagnosing Muscle Soreness

Molly E. McCue, DVM, MS, PhD, Dipl. ACVIM June 1, 2008

Last year my 18-year-old Quarter Horse mare became very sensitive to touch on her back and hindquarters.

Muscle Disorders in Warmbloods Easily Diagnosed through Biopsy

Stacey Oke, DVM, MSc April 16, 2008

Owners of Warmbloods with debilitating–or sometimes just plain baffling–muscle disorders can get useful and reliable answers about their horses’ conditions through a relatively simple muscle biopsy. So say University of Minnesota researchers,

Polysaccharide Storage Myopathy: Blame It on the Genes

Stacey Oke, DVM, MSc April 11, 2008

A genetic mutation in an enzyme called muscle glycogen synthase might be responsible for polysaccharide storage myopathy (PSSM)–a debilitating and life-threatening disease in horses characterized by abnormally high glycogen (the storage form of

2007 Morris Animal Foundation Equine Research Wrap-Up

Edited Press Release December 14, 2007

The results of equine research funded by the Morris Animal Foundation (MAF) in 2007 added to scientists’ understanding of foal pneumonia, hereditary muscle disorders, laminitis, and pharmacology.

New Research on PSSM Prevalence, Heritability in Progress

Erin Ryder October 4, 2007

Researchers with the University of Minnesota have identified polysaccharide storage myopathy (PSSM) in 6-12% of overtly healthy Quarter Horses on six farms involved in a new study. They also said the disease could be more common within certain

Morris Animal Foundation Funding 11 Equine Studies in 2008

Press Release September 25, 2007

In 2008, the Morris Animal Foundation (MAF) will fund about 120 animal health studies, including 11 new and continuing studies for horses. Equine enthusiasts are invited to sponsor or co-sponsor one of these studies with a total gift of $3,000 o