negative for type 1 PSSM - now what? (short of $500 muscle biopsy)

[LDavis104]

Waiting for vet to call me back... in the meantime...

Long story short, Peppy's muscle enzymes were way up, coupled with an episode of extreme stiffness (we attributed stiffness to Ehrlichiosis, seems tying up and Ehrlichiosis happened at the same time). Vet had me send a hair sample off for type 1 PSSM, test came back negative.

Vet originally said if this came back negative, we'd need to do a muscle biopsy for type 2 PSSM, which she said would be about $500. Hubby and checkbook say no to the $500 muscle biopsy.

Peppy is not regularly having tying up episodes, the stiffness we saw during the Ehrlichiosis was the 1st I'd ever seen in the year and a half I've owned him. I don't notice any discomfort.

So without doing a biopsy, I think the next thing would be to do bloodwork to check muscle enzyme levels again, right? Or are they only raised after a tying up episode? It's also been suggested I test for Selenium and Vit E levels?

Just wanting to get some ideas before speaking with the vet. I'm sure she'll be guiding me on what to do next, but want to get some more info in the meantime.

Also, could stiffness from Ehrlichiosis be the cause of elevated muscle enzymes? Vet didn't associate the two together.

[Melyni]

Waiting for vet to call me back... in the meantime...

Long story short, Peppy's muscle enzymes were way up, coupled with an episode of extreme stiffness (we attributed stiffness to Ehrlichiosis, seems tying up and Ehrlichiosis happened at the same time). Vet had me send a hair sample off for type 1 PSSM, test came back negative.

Vet originally said if this came back negative, we'd need to do a muscle biopsy for type 2 PSSM, which she said would be about $500. Hubby and checkbook say no to the $500 muscle biopsy.

Peppy is not regularly having tying up episodes, the stiffness we saw during the Ehrlichiosis was the 1st I'd ever seen in the year and a half I've owned him. I don't notice any discomfort.

So without doing a biopsy, I think the next thing would be to do bloodwork to check muscle enzyme levels again, right? Or are they only raised after a tying up episode? It's also been suggested I test for Selenium and Vit E levels?

Just wanting to get some ideas before speaking with the vet. I'm sure she'll be guiding me on what to do next, but want to get some more info in the meantime.

Also, could stiffness from Ehrlichiosis be the cause of elevated muscle enzymes? Vet didn't associate the two together.

The muscle enzyme levels should only be raised following a bout of tieing up or other significant muscle injury which could include a bout of Ehrlichcosis.

If he is doing okay I would leave it, and see how he does. Only if he gets stiff again would do a follow up.

Make sure his diet has enough magnesium in it (magnesium is involved in muscle relaxation) and that he is not getting too high a sugar or carb intake and then go on, and wait and see if you get another episode.

Good Luck.
Yours
MW

[Tegan]

I haven't personally dealt with PSSM, but I thought I'd point you toward this article. It has a lot of good information.
http://www.morgandressage.org/articles/pssm.html

I would try a feed change and see what happens.

[Fharoah]

I guess I would want to know. Best Wishes!

[M. O'Connor]

It's more usual that any symptoms you would notice as far as the muscle related metabolic disorders (RER/PSSM/EPSM) would follow an unusually stressful workout.

While it's possible that a horse with erlichiosis (a tick-borne disease) might be stressed in some way, the ones I've had who have experienced it are hardly in shape to exercise themselves into a tying up episode--on the contrary, they are miserable, feverish, depressed, and very passive. They improve quickly with antibiotic treatment, but I couldn't imagine subjecting them to exercise and work until they had fully recovered, and then some.

While the enzyme levels shoot up during a tying up 'episode,' some horses that tie up regularly, or are borderline as far as showing symptoms might have a higher baseline level that could still be in the normal range.

Generally, you would not look at the enzyme levels only once; you would do it twice, the first time when your horse is experiencing the onset of stiffness, and the second a number of days later to extrapolate the rate of recovery, and to determine when the horse will be back to "normal."

FWIW, I have a confirmed RER horse whose disorder led to my association with KER; he is also uniquely sensitive to allergens (every time he gets a shot he reacts, for instance), so I've never sent tissue for biopsy because of this. He's been on a specialized diet (ReLeve) and hasn't tied up in years.

Research has improved the knowledge of what causes these disorders (genetic predisposition, dietary factors, and inappropriate workload) and how to manage them (careful management of stress reduction, diet, and exercise levels).

I would think that you would want to wait until your horse has recovered fully from the erlichiosis before assessing the necessity of further testing for muscle stiffness.

[LDavis104]

It's more usual that any symptoms you would notice as far as the muscle related metabolic disorders (RER/PSSM/EPSM) would follow an unusually stressful workout.

While it's possible that a horse with erlichiosis (a tick-borne disease) might be stressed in some way, the ones I've had who have experienced it are hardly in shape to exercise themselves into a tying up episode--on the contrary, they are miserable, feverish, depressed, and very passive. They improve quickly with antibiotic treatment, but I couldn't imagine subjecting them to exercise and work until they had fully recovered, and then some.

While the enzyme levels shoot up during a tying up 'episode,' some horses that tie up regularly, or are borderline as far as showing symptoms might have a higher baseline level that could still be in the normal range.

Generally, you would not look at the enzyme levels only once; you would do it twice, the first time when your horse is experiencing the onset of stiffness, and the second a number of days later to extrapolate the rate of recovery, and to determine when the horse will be back to "normal."

FWIW, I have a confirmed RER horse whose disorder led to my association with KER; he is also uniquely sensitive to allergens (every time he gets a shot he reacts, for instance), so I've never sent tissue for biopsy because of this. He's been on a specialized diet (ReLeve) and hasn't tied up in years.

Research has improved the knowledge of what causes these disorders (genetic predisposition, dietary factors, and inappropriate workload) and how to manage them (careful management of stress reduction, diet, and exercise levels).

I would think that you would want to wait until your horse has recovered fully from the erlichiosis before assessing the necessity of further testing for muscle stiffness.

Some additional info - Peppy had been recovered from Ehrlichiosis fully for about a week prior to his bloodwork. The bloodwork was taken to check his liver, as he had a mysterious face "crud", and the vet said sometimes this can be a clue to liver problems.

As far as work, Peppy hadn't been ridden for about 24 hrs prior to the blood draw, and it was a very light workout. He didn't show any soreness or stiffness during or after our ride, and hadn't been sore or stiff at all for a week.

He wasn't getting turnout because of his paddock being too icy. His tying up definitely didn't come after a hard workout. His occurred while he was on stall rest. The only stiffness I saw was while he was on rest for Ehrlichiosis, we assumed it was ALL from the Ehrlichiosis, but muscle enzymes were really high about a week after his stiffness was gone. Unless he had a tying up episode overnight in his stall that I didn't see...

Not sure if any of this means anything, but I think you are confirming the need for additional bloowork.

[M. O'Connor]

Any work following a period of rest could theoretically cause an episode of tying up. In fact, that's actually the most likely time for it to occur; what was once known as "Monday-morning disease" would strike work horses after they returned to work on a Monday following Sunday, traditionally a day of rest when they might be stall bound.

I would think that in light of your horse's bout with illness, it could be more likely that he would be stressed by less work than you might expect otherwise. The symptoms of erlichiosis can be really acute; depending on the severity, I would think that a period of weeks would have to pass before I'd attempt putting a horse back in any sort of work.

Keep in mind that ANY exercise counts toward your horse's safe exertion threshold total; for instance, if your horse had been turned out and played vigorously prior to your work session (even by a day or so earlier) this could have resulted in his getting a quantity of exercise you hadn't realized he'd had. And possibly even his having an episode that you wouldn't have seen, particularly if you weren't even there!

So you should monitor his exercise and fitness level carefully as you return him to work. Observation will help you and your vet determine whether your horse is having trouble returning to work and figure out if further bloodwork is necessary.

But if it is, it will need to be done at intervals to figure out what is really going on and decide whether measures like dietary modification could help.

[Dalemma]

I have not heard of PSSM/ESPM referred to as type 1 verses type 2.

80% of horses with PSSM have a gene that can now be identifed by doing a blood test.........but there is another gene out there that they have not been able to identify......20% of horses have this type of gene and the only way you can diagnosis it is with a muscle biopsy as it does not show up in blood work.

Emma

[M. O'Connor]

The bloodwork shows the effects (abnormal blood enzymes), rather than the cause of these disorders.

Regardless of the the specific genetic abnormality that causes symptoms to appear, a similar treatment protocol is recommended (managed exercise, together with a low starch/ high fat diet) and has been shown to be effective.

I need to study up, but it's my impression that as the research is developing, there is a trend toward more precisely placing a diagnosis within a genetic category.

At this point, whether to test or not seems to be a question of deciding whether the existence of a test is an indication of its necessity, and whether undergoing the expense of testing will make a meaningful contribution to the outcome.

[Dalemma]

Testing for me gave me some answers that I would not have been able get had I not tested.......my guy falls in the 20% that does not show up in blood work..........he was not doing well even on the diet and a regular exercise program......he still was not rideable.......doing the test confirmed that there was too much muscle involvement too make him a rideable horse.......so it made the decision to retire him at the age of 6 easier to do.....for me the muscle biopsy ended a long battle of trying.

Dalemma

[M. O'Connor]

That's a shame, D--what diet and exercise program were you following? What breed is your horse? I have known some who did not come around (and others who weren't worth the considerable effort it takes to try).

Blood tests, at intervals, are used simply to determine the severity of an accute episode and help in determining when work can be resumed. They won't tell you why the episode occured, or how to prevent another from happening. You are correct about that--yours is an example of the extra testing being worthwhile, in more or less 'ruling out' a successful return to work.

[Dalemma]

Thanks.........it was sad........he is a 16 hand, dun appendix with a great personality and great conformation....my vet really likes him.

Dr. Valberg did the biopsy and I followed her diet and exercise plan.........plus I did the oil.........so it was a low sugar diet, no grain what so ever.........a low selenium aggravated the soreness issue but that has been addressed and he is fine as a companion........he definitely has some sore days.....kinda depends on how much running around he does with his buddy. His pasture time must also be strictly monitored as his heart rate sky rockets to 60 bpm if he gets too much......I will see if I can find a picture to attach.

http://i149.photobucket.com/albums/s77/DalEmma2002/Dennystanding.jpg

Dalemma

[LDavis104]

At this point, whether to test or not seems to be a question of deciding whether the existence of a test is an indication of its necessity, and whether undergoing the expense of testing will make a meaningful contribution to the outcome.

That's what I was thinking - if the muscle biopsy did come back positive, we would just change his diet and exercise program... Although it would be nice to know for sure, is it a good use of my funds to spend $500 to confirm a needed diet change?

Too bad I can't do a muscle biopsy myself, as the same place that checked his hair sample charges $95 to test the muscle ;)

Vet was out last week and drew more blood to check levels again... I'll probably hear something from her Monday or Tuesday.

Oh and the "type 1" and "type 2" termonology was from the Univeristy of Minnesota Vet Diagnostic Lab website (they did the type 1 testing) http://www.cvm.umn.edu/umec/lab/PSSM/home.html

[LDavis104]

Testing for me gave me some answers that I would not have been able get had I not tested.......my guy falls in the 20% that does not show up in blood work..........he was not doing well even on the diet and a regular exercise program......he still was not rideable.......doing the test confirmed that there was too much muscle involvement too make him a rideable horse.......so it made the decision to retire him at the age of 6 easier to do.....for me the muscle biopsy ended a long battle of trying.

Dalemma

Wow sounds like he had a really bad case :( Mine is 5 yrs old.

[Dalemma]

Yup his case is pretty bad.....Dr. Valberg actually thought that he may carry two copies of the gene due to the fact that his heart seems to be affected by sugars as well.......but we do not know if it is directly or indirectly affected........but the testing proved he only had one copy of type 2 the gene that has not been identified. According to Dr. Valberg........horses with type two generally do better but guess that is not the case with my guy.

Dalemma

PS Thanks for the link....I have been to that site but had not noticed the description of type one verse type two......is this a fairly new information?

[Dalemma]

That's what I was thinking - if the muscle biopsy did come back positive, we would just change his diet and exercise program... Although it would be nice to know for sure, is it a good use of my funds to spend $500 to confirm a needed diet change?

Too bad I can't do a muscle biopsy myself, as the same place that checked his hair sample charges $95 to test the muscle ;)

Vet was out last week and drew more blood to check levels again... I'll probably hear something from her Monday or Tuesday.

Oh and the "type 1" and "type 2" termonology was from the Univeristy of Minnesota Vet Diagnostic Lab website (they did the type 1 testing) http://www.cvm.umn.edu/umec/lab/PSSM/home.html

Well for me another reason why I went ahead with the muscle biopsy is I did the diet switch and had been on the oil and low sugar diet for at least 6 months to 8 months and was still not able to ride him.........while the muscles over his rump softened with the addition of oil....his back and hind end were still sore......the reason was not so much to confirm the disease but to confirm the involvement of the disease and whether he held two copies of the gene......having two copies of the gene would pretty much have meant the end for my guy.

My guy has never actually tied up due to exercise he was just plain sore.......and more on one side than the other as he would cross canter to the right.......but cantered fine to the left......it was actually the cross canter that got me thinking something wasn't quite right and then things from there just went from bad to worse.

Dalemma

[draftgirl01]

My mare tied up terribly after eye surgery this summer. After her surgery I noticed something was terribly wrong with her when she came home and my vet came and pulled blood. Her creatine kinase level was at 48386 and other levels were sky high. Vet hospital suspected she had underlying EPSM or PSSM because of her breeding that caused a problem. We sent blood to Dr. Valberg and it came back negative. She was tested for Type 1 PSSM characterized by a mutation in the GYS1 gene.

At that point, I contacted Dr. Valentine again and removed my mare from all grain. She is now on beet pulp with Accel vitamins and gets cocosoya oil. She has always been on a low starch/carb diet but with how bad she was and discussing it with my vet, doing a muscle biopsy was an option, but both also recommended the change in her diet.

It has been a very long road to get her back, we were pulling blood a couple times a week to make sure the levels would going down and not up anymore.

So, for me, I just leave her on this diet at this point and she likes it. All levels have returned to normal, except her BUN level which it a bit above normal but vet believes will be her new "normal" level with everything she went threw.