Your horse did not inherit the PSSM1 mutation and is considered normal. They cannot pass on the mutation to offspring themselves.

• Muscle cramps and tremors. Often is mistaken as a horse who is colicking or tying up.
• Sweating/anxiety.
• Lameness.
• Poor performance.
• These horses are often described as lazy.
• Some horses may not want to collect when being ridden.
• Horses may stand camped out or stretched out more than normal.
• Horses with severe episodes may have urine that is coffee colored. If this occurs, an immediate call to the vet is necessary.

For horses with PSSM1, a diet high in carbohydrates and/or lack of exercise appear to exacerbate PSSM1. Reducing the amount of glucose in a horse’s diet, coupled with a consistent exercise routine, will likely reduce episodes.

Stress can also trigger an episode in a PSSM1 horse. This includes radical changes in diet and/or exercise. Horses with PSSM are more likely to have an episode when they have been stalled for extended periods of time then followed by intense exercise. Keeping them turned out and ensuring regular exercise is important to preventing an episode.

Managing PSSM1 with diet and exercise is vital to reducing the number and severity of episodes.

Horses with PSSM1 should have minimal starch and sugar in their diets. If a horse is not an easy keeper and has higher caloric needs, a fat supplement may be added. Several feed companies make low starch high fat feeds that are a good option for PSSM1 management. Pasture grasses and hay should be tested to ensure sugar levels are acceptable. A grazing muzzle may be required if levels are too high.

Exercise should be done regularly. If a prolonged break is necessary, gradually reintroduce exercise. PSSM1 horses should be turned out and not stalled for long periods of time. Many horses that are managed properly can have successful performance careers.

If your horse is experiencing an episode, call your veterinarian immediately. Your veterinarian may administer a sedative and/or banamine to relieve anxiety and/or pain.

If you are riding the horse when the episode happens, stop exercising immediately. Do not force the horse to walk. Do your best to make the horse calm and comfortable.

Give your horse small, frequent sips of water. You may add electrolytes to a bucket of water but have plain water available as well. Remove all grain, and only allow your horse access to hay until symptoms subside.

Once your horse’s symptoms subside, they may have free access to water, as well as a small turnout area. Consult your veterinarian or nutritionist to formulate a feeding plan moving forward to better meet your horse’s needs.

When breeding any horse, probability of offspring inheriting genetic mutations should always be a factor to consider.

Expected breeding outcomes are shown below. A normal PSSM gene is indicated by "N". A mutated PSSM gene is indicated by "PSSM1".

100% chance of a foal who does not carry a copy of PSSM1 and is considered normal. They cannot pass on the mutation to offspring themselves.

50% chance of a foal who does not carry a copy of PSSM1 and is considered normal. They cannot pass on the mutation to offspring themselves.

50% chance of a foal who inherits one copy and is likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

100% chance of a foal who inherits one copy and likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

• MSU-PSSM1
• UCDAVIS-PSSM1
• UMN-PSSM1
• VGL-PSSM1

Your horse inherited one copy of PSSM1. Your horse may have episodes of PSSM but could be mild to moderate, though severe is possible. Your horse can pass PSSM on to offspring.

• Muscle cramps and tremors. Often is mistaken as a horse who is colicking or tying up.
• Sweating/anxiety.
• Lameness.
• Poor performance.
• These horses are often described as lazy.
• Some horses may not want to collect when being ridden.
• Horses may stand camped out or stretched out more than normal.
• Horses with severe episodes may have urine that is coffee colored. If this occurs, an immediate call to the vet is necessary.

For horses with PSSM1, a diet high in carbohydrates and/or lack of exercise appear to exacerbate PSSM1. Reducing the amount of glucose in a horse’s diet, coupled with a consistent exercise routine, will likely reduce episodes.

Stress can also trigger an episode in a PSSM1 horse. This includes radical changes in diet and/or exercise. Horses with PSSM are more likely to have an episode when they have been stalled for extended periods of time then followed by intense exercise. Keeping them turned out and ensuring regular exercise is important to preventing an episode.

Managing PSSM1 with diet and exercise is vital to reducing the number and severity of episodes.

Horses with PSSM1 should have minimal starch and sugar in their diets. If a horse is not an easy keeper and has higher caloric needs, a fat supplement may be added. Several feed companies make low starch high fat feeds that are a good option for PSSM1 management. Pasture grasses and hay should be tested to ensure sugar levels are acceptable. A grazing muzzle may be required if levels are too high.

Exercise should be done regularly. If a prolonged break is necessary, gradually reintroduce exercise. PSSM1 horses should be turned out and not stalled for long periods of time. Many horses that are managed properly can have successful performance careers.

If your horse is experiencing an episode, call your veterinarian immediately. Your veterinarian may administer a sedative and/or banamine to relieve anxiety and/or pain.

If you are riding the horse when the episode happens, stop exercising immediately. Do not force the horse to walk. Do your best to make the horse calm and comfortable.

Give your horse small, frequent sips of water. You may add electrolytes to a bucket of water but have plain water available as well. Remove all grain, and only allow your horse access to hay until symptoms subside.

Once your horse’s symptoms subside, they may have free access to water, as well as a small turnout area. Consult your veterinarian or nutritionist to formulate a feeding plan moving forward to better meet your horse’s needs.

When breeding any horse, probability of offspring inheriting genetic mutations should always be a factor to consider.

Expected breeding outcomes are shown below. A normal PSSM gene is indicated by "N". A mutated PSSM gene is indicated by "PSSM1".

50% chance of a foal who does not carry a copy of PSSM1 and is considered normal. They cannot pass on the mutation to offspring themselves.

50% chance of a foal who inherits one copy and is likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

25% chance of a foal who does not carry a copy and is considered normal. They cannot pass on the mutation to offspring themselves.

50% chance of a foal who inherits one copy and is likely to experience mild/moderate symptoms, with severe symptoms possible. This horse can pass PSSM1 on to offspring.

25% chance of a foal who inherits two copies and will likely experience severe symptoms. This horse will pass it on to offspring 100% of the time regardless of the other parent’s PSSM1 status.

50% chance of a foal who inherits one copy and likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

50% chance a foal who inherits two copies and will likely experience severe symptoms. This horse will pass it on to offspring 100% of the time regardless of the other parent’s PSSM1 status.

• MSU-PSSM1
• UCDAVIS-PSSM1
• UMN-PSSM1
• VGL-PSSM1

Your horse inherited two copies of PSSM1 and is homozygous for the mutation. They are likely to have episodes that are more severe than carriers of PSSM1. This horse will pass it on 100% of the time regardless of the other parent’s PSSM status.

• Muscle cramps and tremors - Often is mistaken as a horse who is colicking or tying up.
• Sweating/anxiety.
• Lameness.
• Poor performance.
• These horses are often described as "lazy".
• Some horses may not want to collect when being ridden.
• Horses may stand "camped out" or stretched out more than normal.
• Horses with severe episodes may have urine that is coffee colored. If this occurs, an immediate call to the vet is necessary.

For horses with PSSM1, a diet high in carbohydrates and/or lack of exercise appear to exacerbate PSSM1. Reducing the amount of glucose in a horse’s diet, coupled with a consistent exercise routine, will likely reduce episodes.

Stress can also trigger an episode in a PSSM1 horse. This includes radical changes in diet and/or exercise. Horses with PSSM are more likely to have an episode when they have been stalled for extended periods of time then followed by intense exercise. Keeping them turned out and ensuring regular exercise is important to preventing an episode.

Managing PSSM1 with diet and exercise is vital to reducing the number and severity of episodes.

Horses with PSSM1 should have minimal starch and sugar in their diets. If a horse is not an easy keeper and has higher caloric needs, a fat supplement may be added. Several feed companies make low starch high fat feeds that are a good option for PSSM1 management. Pasture grasses and hay should be tested to ensure sugar levels are acceptable. A grazing muzzle may be required if levels are too high.

Exercise should be done regularly. If a prolonged break is necessary, gradually reintroduce exercise. PSSM1 horses should be turned out and not stalled for long periods of time. Many horses that are managed properly can have successful performance careers.

If your horse is experiencing an episode, call your veterinarian immediately. Your veterinarian may administer a sedative and/or banamine to relieve anxiety and/or pain.

If you are riding the horse when the episode happens, stop exercising immediately. Do not force the horse to walk. Do your best to make the horse calm and comfortable.

Give your horse small, frequent sips of water. You may add electrolytes to a bucket of water but have plain water available as well. Remove all grain, and only allow your horse access to hay until symptoms subside.

Once your horse’s symptoms subside, they may have free access to water, as well as a small turnout area. Consult your veterinarian or nutritionist to formulate a feeding plan moving forward to better meet your horse’s needs.

When breeding any horse, probability of offspring inheriting genetic mutations should always be a factor to consider.

Expected breeding outcomes are shown below. A normal PSSM gene is indicated by "N". A mutated PSSM gene is indicated by "PSSM1".

100% chance of a foal who inherits one copy and likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

50% chance of a foal who inherits one copy of PSSM1 and likely to experience mild/moderate symptoms with severe symptoms possible. This horse can pass PSSM1 on to offspring.

50% chance of a foal who inherits two copies of PSSM1 and will likely experience severe symptoms. This horse will pass it on to offspring 100% of the time regardless of the other parent’s PSSM1 status.

100% chance a foal who inherits two copies and will likely experience severe symptoms. This horse will pass it on to offspring 100% of the time regardless of the other parent’s PSSM1 status.

• MSU-PSSM1
• UCDAVIS-PSSM1
• UMN-PSSM1
• VGL-PSSM1