Elevated Muscle Enzymes

[Cor]

Hi all - my senior mare has been a bit stiff and sore recently so I have decided to bring the vet who has done some blood tests on her. During his checkup he has also detected some muscle issues which were also evident in the blood tests as the muscle enzymes LDH, CPK and AST values were quite elevated. He has recommended additional supplements and intramuscular joint supplements to help her. Does Anyone else have experience with these kind of issues and if yes what have you done to help your horse?

 

[flintfootfilly]

Only just seen this thread. Yes, all my five (formerly 6) ponies have raised muscle enzymes and work intolerance.

Will respond fully when I am at my computer later today.

What is your mare likein her work? Has she had any foals? Did she retain her placenta? What part of the uk are you in?

Sarah

 

[flintfootfilly]

OK, am up and about, and on my laptop now, so can type a fuller reply.

With my gang, I have been battling for 2 years to get to the bottom of their problems. Having considered as many causes of muscle problems as I can, I believe that the problem in my gang is due to long term dietary selenium deficiency.

Take a look at this useful summary of equine muscle problems by Monica Aleman to see the range of possible causes of muscle disease: http://www.respe.net/system/files/documents_equine_muscle_disorders.pdf For my gang, I just felt that because all the ponies were affected to varying degrees, there had to be an environmental factor involved, so started to look into selenium deficiency as the possible cause.

Unfortunately, blood selenium reference ranges are poorly established in the UK. One lab which carries out the test does not offer a reference range, and some other labs who report that lab's results come up with their own reference range. However, the long and short is I believe the reference ranges are not appropriate and therefore I've not found blood selenium (or glutathione peroxidase, GSHPX, as an indicator of selenium) to be helpful at all.

Also unfortunately, I've not come across any vet who recognises chronic selenium deficiency in horses causing muscle problems. This is despite it being well documented in other species. As far as I've found, vets only seem to recognise selenium deficiency in horses if they pretty much can't stand, or if their symptoms are very very pronounced.

First port of call, I'd suggest you check out this map showing soil selenium levels for England and Wales: http://www.bgs.ac.uk/nercsoilportal/maps.html It was produced by NERC following a detailed survey of England and Wales. Dark blue and mid blue areas are deficient in selenium. Turquoise, green, yellow/orange/red are adequate or high.

Selenium levels can vary from field to field, but the map above should give some idea of whether you should consider selenium deficiency as a possible cause of your horse's problems.

It's also worth having hay/grass tested for selenium levels, so you know exactly what the status of the forage is. I use Sciantec in Cawood, Selby for this, and they have always been great to deal with, and very speedy with results. However, some people choose to use a company like Forageplus who will not only arrange for the analysis to be done, but will also (For a fee) interpret the result. You do need to be able to interpret the results correctly, because unfortunately many forage analysis reports are extremely misleading, commenting on levels as "low", "average" or "high", when these comments relate only to the samples they have tested, and not to whether the levels are adequate or not.

Forage selenium levels need to be 0.1mg/kg DM or above to be adequate. Mine are 0.03-0.05mg/kg DM.

Check what levels of selenium are being given in the rest of the diet. Manufacturers don't always quote them on labels, so do check direct with the manufacturer what the level is, and also what type of selenium it is.

NRC's recommendation is for a minimum of 1mg of selenium/day/500kg horse in total (ie including hay, grass and all other feeds/supplements).

Through monitoring my gang's blood regularly over a 2 year period, I have built up a bit of a pattern in terms of what may be helping bring the muscle enzymes down. After 10 months on a balancer with only inorganic selenium (sodium selenite), their AST, CK and LDH either levelled off or started to rise. Whereas, after 4-5 months on a balancer with organic selenium (selenium yeast), CK dropped significantly. This has happened on two separate occasions, and I'm hoping the next few months will see further improvements.

So my belief is that it's only organic selenium (selenium yeast) which can make a difference to my gang. Selenium yeast is known to be more bioavailable than sodium selenite, and this certainly rings true with my gang's many blood results (about 74 blood tests in all, so around a 12-14 tests per pony).

So my recommendation would be to switch to a balancer that provides around 1mg of selenium in the form of selenium yeast/500kg horse/day. For me, this means either Blue Chip or Dengie Alfa A balancers. Some people use Pro Hoof, and others use Forageplus, but for me I don't see any scientific justification for using the high copper/zinc levels that are included in Forageplus.

Another aspect to consider is EPSM (also known as PSSM). My gang's signs of work intolerance are very similar to those found in EPSM horses (Beth Valentine, a leading EPSM vet has watched video of them and says they appear exactly as she sees in EPSM horses). It is quick, easy and cheap to have a horse's hair sample tested for the genetic form of EPSM (through Animal Genetics in Cornwall. No need to involve your vet). It costs about £30 per sample.

There is another form of EPSM "type 2" whose cause isn't known, and this can only be tested for by biopsy which is more invasive and more expensive (mine was about £500 in all). So personally, I wouldn't go down that route again, but I think the type 1 hair test is worth having, because that will show conclusively if the EPSM gene mutation is causing the problems.

Other things to consider are if you've done anything different in terms of management recently. When did your mare's soreness first show up. Has she ever shown work intolerance of any form, or anything unusual that might indicate muscle problems over a longer period.

Take a look on youtube. Search for Flintfoot Dales ponies, and you should find 3 videos showing my gang's work intolerance. That'll give you an idea of some of the signs.

I have to say you will be very very unlikely to find much support from vets for anything you choose to look into on this score. My belief is that selenium deficiency is widespread in the UK, but that most horseowners get talked down by their vets so never get to the bottom of it. The only reason I've carried on and spent thousands of hours researching causes is because I just don't believe that it's normal for 6 ponies to all show work intolerance and raised muscle enzymes without an underlying cause. However, I've had to just grit my teeth and learn to live with the ridiculous comments made by some professionals who either don't believe there's a problem, or who don't believe it's selenium deficiency but can't offer a better suggestion.

Do let us know how you get on.

Sarah