This is why I keep banging on about magnesium......

excess magnesium is not harmless. It can interfere with uptake of some other minerals and has been accused of CAUSING excitement in horses when used in excess. It also causes diarrhoea at high levels.
Of course, an excessive amount will depend on the current status of each individual horse's own levels, so some may be deficient even though they are kept with others that are not deficient.

I think mine is one of these cases. He had been moved to a new field with a magnesium lick in it for the cows - he was mental for two weeks until i caught him licking this and promptly removed it to be told it was magnesium.
 
To much magnesium actually makes the situation worse as it can stop the animals ability to use what is stored in the body so it actually becomes dependant on artificial sources to maintain its need. It is a known phenomena in dairy cows (an animal that has a huge need of magnesium) that over supplemented cows are more prone to staggers than those that are managed correctly . This is because the animal cannot use its reserves at the time of greatest need ie going onto lush spring or autumn grass.
s!!

I think you've confused calcium with magnesium here... Both of a risk around calving but magnesium you can supplement freely in the run to calving to prevent staggers as magnesium is not really stored to any great degree whereas if you supplement calcium you increase the risk of hypocalcemia as the cow can't then mobilize its calcium as you explained above.
The mechanism of calcium storage and metabolism is quite complex and you actually want to restrict it in cattle before calving to get the cow mobilizing her calcium supplies before calving and lactation. Magnesium is more straight forward with most cows just receive a magnesium supplement as part of their daily ration to compensate for the deficit in their diet which usually has been formulated with consideration of mineral balance .
 
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I think you've confused calcium with magnesium here... Both of a risk around calving but magnesium you can supplement freely in the run to calving to prevent staggers as magnesium is not really stored to any great degree whereas if you supplement calcium you increase the risk of hypocalcemia as the cow can't then mobilize its calcium as you explained above.
The mechanism of calcium storage and metabolism is quite complex and you actually want to restrict it in cattle before calving to get the cow mobilizing her calcium supplies before calving and lactation. Magnesium is more straight forward with most cows just receive a magnesium supplement as part of their daily ration to compensate for the deficit in their diet which usually has been formulated with consideration of mineral balance .

Sorry I am not confusing the two . I know only too well the metabolism of both minerals and was using the example of pre turnout in spring and on lush autumn grass which is the time most high yielding cows are prone to staggers not at calving.
The cow can store very little magnesium in her body however over supplementing at the wrong time depletes her ability to mobilise what she does store., Calcium is a totally different ball game as indeed is phosphorus deficiency .

The only true way to tell if your horse is deficient rather than guessing is to run a metabolic profile,very rarely will you see horses on grazing that may be deemed to be likely to cause staggers in cows and indeed most risk in cows will be in heavy milking cows.
 
Still can't find anything, only stuff about animals with compromised renal function and when it's used in high doses (magnesium sulphate) to treat impaction colic, but that's due to other factors too, dehydration and electrolyte imbalances etc.

Can't find anything which confirms that feeding Mg can lead to hypermagnesemia, only that it's a very rare condition in otherwise healthy animals.
Maybe I'm looking in the wrong place, it's past my bedtime, I'm up at 4:30 every day (bread baker), gotta sleep now..

I think hypermagnesaemia may be the wrong search term to use. I agree that it occurs with over treatment of magnesium in situations like impaction {http://www.library.hverf.org/eve/j.2042-3292.2006.tb00461.x.pdf} , but blood Mg levels are not considered a good indicator of what is going on in the rest of the body (e.g. Mg can out-compete Ca at some of calciums binding sites).
I also agree that many problems will be related to underlying factors (otherwise problems would be a lot more common if most horses didn't cope with the extra Mg). For example, Mg is excreted through the kidney and kidney probs will reduce excretion. But kidney damage itself doesn't show until there is a lot of damage (so some horses could have unknown issues) and when you think that many cases of colic have dehydration as the main factor (shaky memory remembers reading a figure of at least half, but someone else might be able to clarify) then dehydration may be more common than many people realise (with snowball effect of not pee'ing out excess supplements sufficiently).

If high levels of phosphorus are also given, then high dietary magnesium can lead to urolithiasis (stones/gravel in urinary tract including kidneys) and there is always the possibility that this too could exacerbate the problem. [ref for urolithiasis horse/Mg/Ca = http://link.springer.com/chapter/10.1007/978-1-84628-483-0_31#page-1. Sorry can't access whole book]

Epsom salts are a laxative (osmotic) and although diarrhoea or loose droppings are not common with most Mg supplements, diarrhoea is only the visible effect seen at the end of the digestive tract whereas Mg (and Ca) are absorbed in the small intestine. Could the laxative effect even temporarily decrease blood magnesium levels (as there will still be the obligatory losses in the gut and kidney but with reduced absorption)? Of course, any diarrhoea that did occur would also for a short time interfere with absorption of other nutrients.

The interaction between magnesium and parathyroid hormone is also complex and not fully understood, which raises another set of possibilities that can only be clarified in the future by more research.

True magnesium deficiencies in equines are believed to be uncommon, so do all horses that are given magnesium need it? Many sources state that effects of long term doses of excess high levels of Mg have not been studied, and that the required normal levels are only an estimate (e.g. NRC).
This abstract is also interesting, not because of its title but because of the last sentence http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0396.2009.00921_11.x/abstract "Lastly over-supplementation of horses should be avoided to reduce the environmental impact of excess nutrients excreted in urine and faeces"

I can't find the info about the accusation that excess Mg causes excitement stored on my computer so i think it might be a printed of one that is one of the boxes in the garage. I will have a rummage on the weekend.
good luck with the bread baking! [mouth watering at the memory of the smell of freshly baked bread]
 
The element magnesium is a constituent of the chlorophyll molecule, so if the grass is green the horse will be ingesting it.
 
I think hypermagnesaemia may be the wrong search term to use. I agree that it occurs with over treatment of magnesium in situations like impaction {http://www.library.hverf.org/eve/j.2042-3292.2006.tb00461.x.pdf} , but blood Mg levels are not considered a good indicator of what is going on in the rest of the body (e.g. Mg can out-compete Ca at some of calciums binding sites).
I also agree that many problems will be related to underlying factors (otherwise problems would be a lot more common if most horses didn't cope with the extra Mg). For example, Mg is excreted through the kidney and kidney probs will reduce excretion. But kidney damage itself doesn't show until there is a lot of damage (so some horses could have unknown issues) and when you think that many cases of colic have dehydration as the main factor (shaky memory remembers reading a figure of at least half, but someone else might be able to clarify) then dehydration may be more common than many people realise (with snowball effect of not pee'ing out excess supplements sufficiently).

If high levels of phosphorus are also given, then high dietary magnesium can lead to urolithiasis (stones/gravel in urinary tract including kidneys) and there is always the possibility that this too could exacerbate the problem. [ref for urolithiasis horse/Mg/Ca = http://link.springer.com/chapter/10.1007/978-1-84628-483-0_31#page-1. Sorry can't access whole book]

Epsom salts are a laxative (osmotic) and although diarrhoea or loose droppings are not common with most Mg supplements, diarrhoea is only the visible effect seen at the end of the digestive tract whereas Mg (and Ca) are absorbed in the small intestine. Could the laxative effect even temporarily decrease blood magnesium levels (as there will still be the obligatory losses in the gut and kidney but with reduced absorption)? Of course, any diarrhoea that did occur would also for a short time interfere with absorption of other nutrients.

The interaction between magnesium and parathyroid hormone is also complex and not fully understood, which raises another set of possibilities that can only be clarified in the future by more research.

True magnesium deficiencies in equines are believed to be uncommon, so do all horses that are given magnesium need it? Many sources state that effects of long term doses of excess high levels of Mg have not been studied, and that the required normal levels are only an estimate (e.g. NRC).
This abstract is also interesting, not because of its title but because of the last sentence http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0396.2009.00921_11.x/abstract "Lastly over-supplementation of horses should be avoided to reduce the environmental impact of excess nutrients excreted in urine and faeces"

I can't find the info about the accusation that excess Mg causes excitement stored on my computer so i think it might be a printed of one that is one of the boxes in the garage. I will have a rummage on the weekend.
good luck with the bread baking! [mouth watering at the memory of the smell of freshly baked bread]

I am without a doubt ,the only person on the entire planet who would burgle your garage if that is the sort of stuff you keep there. "this is a very strange crime sergeant, the culprit left the van gogh and the family silver but stole an entire truck load of papers on equine metabolism. we are dealing with a sick mind here!"
 
I am without a doubt ,the only person on the entire planet who would burgle your garage if that is the sort of stuff you keep there. "this is a very strange crime sergeant, the culprit left the van gogh and the family silver but stole an entire truck load of papers on equine metabolism. we are dealing with a sick mind here!"

LOL!!! You would have to bring the Van Gogh ad any silver with you!!! I lodge in someone else's house and my bedroom is also my office, with overflow being stored in the garage. Mind you, I do have a lot more boxes of books and papers than other stuff: due to some unavoidable circumstances i lost a lot of my possessions and chose to keep that sort of stuff rather than things like clothes and housewares, so maybe i have a strange mind too! I always thought that there were few of us sane ones in the world.
If you would like the address for dropping off the silver (or any other valuables), then please pm me (she posts reply while chuckling...)
 
Well...I fed my horse mag ox for over a year a few years back now....any difference? Nope...just a fashion fad again..a bit like seaweed or clamping horses mouth shut with a flash.... I seriously didn't see any difference with him on it...put on due to ppid or cushings... Mayne some horses benefit more than others, and as for the grazing in this country, it can vary from field to field, county to county, one cannot be so broad ranging on the deficiency of the grass in a country...
 
Well...I fed my horse mag ox for over a year a few years back now....any difference? Nope...just a fashion fad again..a bit like seaweed or clamping horses mouth shut with a flash.... I seriously didn't see any difference with him on it...put on due to ppid or cushings... Mayne some horses benefit more than others, and as for the grazing in this country, it can vary from field to field, county to county, one cannot be so broad ranging on the deficiency of the grass in a country...

It is far from a fashion fad (did you read Dr Kellon's article??) - without it my horse was virtually unrideable, the only one of 12 home bred horses who responded differently to the normal breaking process, with it completely transformed, and friends have reported similar in their horse. I always suggest giving it a try for a couple of weeks will reveal whether their behaviour/health problems etc are due to a deficiency and is a fraction of the cost of all that testing. Diagnosis by therapy is an accepted form of working out what needs to be done, my vet has done it many times and saved me loadsamoney in the process. And seaweed is a useful form of iodine, the effects of a deficiency will be more long term.
I have never seen any ill effects from supplementing with it, I think you would have to give it in huge quantities to be even close.
 
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It is far from a fashion fad (did you read Dr Kellon's article??) - without it my horse was virtually unrideable, the only one of 12 home bred horses who responded differently to the normal breaking process, with it completely transformed, and friends have reported similar in their horse. I always suggest giving it a try for a couple of weeks will reveal whether their behaviour/health problems etc are due to a deficiency and is a fraction of the cost of all that testing. Diagnosis by therapy is an accepted form of working out what needs to be done, my vet has done it many times and saved me loadsamoney in the process. And seaweed is a useful form of iodine, the effects of a deficiency will be more long term.
I have never seen any ill effects from supplementing with it, I think you would have to give it in huge quantities to be even close.
You are entirely correct that some horses will respond while others won't, and that diagnosis by treatment is acceptable. However, although magnesium is one of the safest things you can give, it doesn't mean that in some horses it isn't having adverse effects (a lot of which would be sub-acute i.e. unseen). There are many many horses that will not be deficient, and many many that will not show effects if given lots anyway, but that doesn't mean that side effects don't occur in others whether seen or not so if there is no effect then prob best not to give unnecessarily. As you say, only 1 of your 12 horses had issues.

Just a note on iodine from seaweed; there were some issues in Australia and New Zealand with feeding seaweed to horses and resulting in neurological problems. This wasn't due to the iodine content, but the source of the seaweed (i.e. what else it contained). I can't remember off the top of my head what it was high in, or which one was safer, but there was a difference in content between the Australian and Norwegian sources that had effects when fed long-term.

PS - i don't mean that iodine is safe in excess either, because it isn't, just that seaweed can contain different levels of other ingredients that might also be a problem.
 
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excess magnesium is not harmless. It can interfere with uptake of some other minerals and has been accused of CAUSING excitement in horses when used in excess. It also causes diarrhoea at high levels.
Of course, an excessive amount will depend on the current status of each individual horse's own levels, so some may be deficient even though they are kept with others that are not deficient.

The only'study' I know of was on five horses, conducted by the man who was promoting a calcium based calmer. It's rubbish.
 
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I think mine is one of these cases. He had been moved to a new field with a magnesium lick in it for the cows - he was mental for two weeks until i caught him licking this and promptly removed it to be told it was magnesium.

And made water resistant with molasses?

Moved to new grass?

It's unlike a horse to take a free access mineral it doesn't need if it's not laced with sugar. Magnesium doesn't taste very nice.
 
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The only'study' I know of was on five horses, conducted by the man who was promoting a calcium based calmer. It's rubbish.
Have you got the link? I remember a review article published comparing more than one study
 
Whilst the information might be perfectly sound, I make a point of taking with a pinch of salt any 'scientific' information presented to me by someone selling something.
Come back when it has been scientifically tested, repeated and peer reviewed by an independent credible body.

(I admit to being a cynic - In my household we routinely refer to the 'scientific sounding' ingredient in commercials for shampoo etc. as "gullibleine".)

Me too.

There are other reasons to promote oneself than selling something. And if she is "writes, teaches, runs online courses", she has an interest in self promotion and getting talked about, as on this thread.

I am the cynic of all cynics. Mine get a cattle salt block in the field so they can help themselves and excrete what they don't need.

Is there truly no scientific based research on this? Difficult to believe when scientists seem to come up with more and more research into totally irrelevant things every day. I heard this morning that goats are apparently a good substitute as a companion animal for humans than dogs, the only downside being that they need a field! And where is the commercial incentive in that gem of wisdom?
 
According to some research I read in the last year ( where I cannot remember it will be linked to ppid, ems and laminitis somewhere) seaweed can be over done as again, not all horses need that much iodine...and it can have adverse effects on the horse...yes I read the article, as I have read several by her as she is linked to ppid ems and laminitis studies...I have read and seen good reports on mag ox with helping to remove fatty pads on obese/poorly horses and working on few horses that are highly strung but other benefits I'm yet to be convinced...however whatever floats your boat and works for you...it's a bit like religion, you don't shout out that everyone should be using or believe it...
 
There is a truly failsafe way to know if you have given your horse too much. It's quite spectacular, advice given is to stand well back before shart's begin to pebbledash stable walls, doors and whatever happens to be in the way willy nilly.

Seen it at the vets. At least they have powerhose-able stables.

To completely kill a horse with Mg, best given IV. Complete renal failure should ensue thus getting rid of the beast. Quite an expensive way to do it since the hunt and other cheaper concoctions of poison exist.

Plus... so many types exist... I mean which one do you choose to effectively despatch a 500kg animal that readily excretes 'excess anything' you give it with flood-inducing waterfalls of wee.

Not an exact science chums. Not an exact science.
 
Clinical manifestation of hypermagnesium

"Hypermagnesemia suppresses the release of acetylcholine and
blocks transmission at the neuromuscular junction. This may cause
an absence of deep tendon reflexes and hypotension, with progression
to peripheral respiratory paralysis and heart block. "

DM, April1988 169

Ronald J. Elin, MD., Ph.D.,

Peer reviewed and been in print since 1988 ;)
 
There is a truly failsafe way to know if you have given your horse too much. It's quite spectacular, advice given is to stand well back before shart's begin to pebbledash stable walls, doors and whatever happens to be in the way willy nilly.

you might well be right, and I do on occasion supplement with magnesium. I do wonder at some of the amounts some people state they are feeding though and surely if a horse is having to excrete it out to that extent, you are putting organs under unnecessary pressure?
 
'Clinical manifestation of hypermagnesium

"Hypermagnesemia suppresses the release of acetylcholine and
blocks transmission at the neuromuscular junction. This may cause
an absence of deep tendon reflexes and hypotension, with progression
to peripheral respiratory paralysis and heart block. "

DM, April1988 169

Ronald J. Elin, MD., Ph.D.,

Peer reviewed and been in print since 1988 '

That assumes an increase in blood level magnesium though, which I don't think tends to occur because of excretion.


Equifeast are yet to produce anything with correct scientific back up as far as I am concerned and mostly uses pretty out of date references, while saying look this has been known for so long, and all the references they do use have issues from a scientific point of view with regards to methodology etc. Anyone that suggests that someone died because they were feeding their horse too much magnesuim when they have no idea of their diet also has no credibility in my book, in addition to the seemingly regular ASA issues...

Now let me find the reply to that assertion on the person dying..
 
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Stolen from David Marlin but with permission to post elsewhere at the time and made more sense than my ramblings.

HOW ABOUT SOME ACCURATE FACTS ON MAGNESIUM AND CALCIUM?
These are the points made in the article and my responses!
"1. EXCESS magnesium impairs brain function"
DAVID MARLIN > Where is the evidence? There is none! One study which fed VERY high amounts of magnesium showed a statistically significant but very small reduction in reaction time.
"2. EXCESS Magnesium from the diet builds up in the body over time"
DAVID MARLIN > Magnesium absorption in horses varies from around 5 to 60%. There is a linear increase between magnesium intake and magnesium excretion in faeces. The more you feed the more gets excreted in faeces. Increased magnesium intake also results in increased magnesium excretion in urine! The body carefully controls blood bone and muscle magnesium concentrations. High magnesium intake increases calcium absorption and vice versa. So strangely if you feed a calcium based calmer you are also INCREASING MAGNESIUM INTAKE! Blood magnesium levels are very tightly regulated. Increased intake does NOT equal increased build up in the body.
"3. This build up can reach levels that impair brain function""
DAVID MARLIN > Actaully, it is ONLY deficiency in magnesium that has been shown to impair brain function. There is no evidence that excess magnesium intake in horses impairs or improves brain function!
"4. Impaired brain function may lead to a sedated controllable horse but it may also lead to increased anxiety and poor decision making and judgement"
DAVID MARLIN > Yes. sedatives such as acepromazine lead to ataxia and are not indicated for horses that have to gallop and jump but are banned. But there is no evidence that high magnesium has this effect.
"5. How do we determine “too much magnesium”?"
DAVID MARLIN > by conducting total balance studies looking at all sources of intake (water, forage, feed, supplements) and by looking at all forms of excretion (faeces, urine, sweat, breath). NOT by measuring plasma (blood) concentrations! A simpler approach is to conduct a urinary creatinine clearance test (paired measurements of magnesium and other electrolytes in plasma and urine).
I will happily defend this position and I would be surprised if there is a single qualified equine nutritionist or experienced scientist that will disagree substantially with this position.

I feed quite a lot of mag ox based on high calcium forage, I have observed no detrimental effects behavioural or otherwise and I guess the pony is old enough that if it is trashing his organs it probably won't be the thing that limits his life.
 
Me too.

There are other reasons to promote oneself than selling something. And if she is "writes, teaches, runs online courses", she has an interest in self promotion and getting talked about, as on this thread.

I am the cynic of all cynics. Mine get a cattle salt block in the field so they can help themselves and excrete what they don't need.

Is there truly no scientific based research on this? Difficult to believe when scientists seem to come up with more and more research into totally irrelevant things every day. I heard this morning that goats are apparently a good substitute as a companion animal for humans than dogs, the only downside being that they need a field! And where is the commercial incentive in that gem of wisdom?

Dr Kellon, and others who agree with her have a much more robust history in science - with associated publications (before doing the courses online etc and being involved in a company selling products) than those who see magnesium as the devils work.
No science is perfect but from reading plenty on both sides I know which one I will stick with currently.
 
Clinical manifestation of hypermagnesium

"Hypermagnesemia suppresses the release of acetylcholine and
blocks transmission at the neuromuscular junction. This may cause
an absence of deep tendon reflexes and hypotension, wpith progression
to peripheral respiratory paralysis and heart block. "

DM, April1988 169

Ronald J. Elin, MD., Ph.D.,

Peer reviewed and been in print since 1988 ;)

I saw this when I was researching. Does it not also say that hypermagnesia is very rare in horses because they really excrete excess, or was that in another study?
 
I saw this when I was researching. Does it not also say that hypermagnesia is very rare in horses because they really excrete excess, or was that in another study?

I've not read that - they may excrete the excess but that assumes that kidney function is 100%. Eevn with 100% kidney function you are going to get some delay before excess is excreted so maybe transitory issues?
 
The thing is, that the clinical manisfestation stuff is also in not done in horses, I certainly haven't experienced any muscle weakness.
It is considered rare, and given the number of us which feed quite a bit the fact that is a rare phenomenon still seems to stand
http://www.merckvetmanual.com/mvm/m..._of_magnesium_metabolism/hypermagnesemia.html

And more is excreted fecally than in urine I think so you aren't entirely reliant on kidney function. But as I say, methodology issues doing anything on only 3 ponies ;)
http://equifeast-shop.com/content/1973_Magnesium_nutruition_research.pdf
 
Clinical manifestation of hypermagnesium

"Hypermagnesemia suppresses the release of acetylcholine and
blocks transmission at the neuromuscular junction. This may cause
an absence of deep tendon reflexes and hypotension, with progression
to peripheral respiratory paralysis and heart block. "

DM, April1988 169

Ronald J. Elin, MD., Ph.D.,

Peer reviewed and been in print since 1988 ;)

Can you give us more information on the demographics of the horses in the study, how magnesium was administered and in what form and also dose would be handy? Also the baseline level of Mg in the blood/serum and what the level was at the time of the adverse events.

It would be useful to know just in case we come across it, we know how to avoid it.
 
Can you give us more information on the demographics of the horses in the study, how magnesium was administered and in what form and also dose would be handy? Also the baseline level of Mg in the blood/serum and what the level was at the time of the adverse events.

It would be useful to know just in case we come across it, we know how to avoid it.

It's a book not a study - I included the full reference if anyone wants to check it out further.

Serum levels are pretty useless for magnesium unless there is renal compromise as most is quickly stored in the tissues or excreted. You would have to sample within 1 hour of giving the magnesium. Urine magnesium levels would be a good way of monitoring - if levels are pretty much zero it is being utilised, if levels rise you have reached an overdose.
 
Can you give us more information on the demographics of the horses in the study, how magnesium was administered and in what form and also dose would be handy? Also the baseline level of Mg in the blood/serum and what the level was at the time of the adverse events.

It would be useful to know just in case we come across it, we know how to avoid it.

Might be wrong but as Ronald J Elin is a MD and not a DVM, I don't think he was referring to horses.
 
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No I think that is a human manifestation of hypermagnesia study.

Equifeast continue with their dodgy adverts, there was one very recently which has been reported to them still making claims they are not, under UK advertising law, allowed to make.
 
No I think that is a human manifestation of hypermagnesia study.

Equifeast continue with their dodgy adverts, there was one very recently which has been reported to them still making claims they are not, under UK advertising law, allowed to make.

Some of the claims Mr Green makes are truly shocking. I remember a thread on here from a few years ago where he tried - and failed miserably - to convince that horses spook because they're insane and irrational and bad risk assessor a. He didn't believe the fight or flight response was a thing :eek:
 
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