Atypical sympathy - a new disease?

cptrayes

cptrayes

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I'm very confused about atypical myopathy it seems to have sprung out of nowhere and suddenly loads of horses are dying from it.

I am guessing that some cases of grass sickness were actually AM, but even so, there seem to be far more cases of AM than there ever were of grass sickness, or am I imagining that?


Have we changed something about the management of horses that is making them more prone to getting this terrible disease?

I'm wondering if, for example, it could have anything to do with is feeding such 'clean' food these days with preservatives in them that has caused an increase in horses that have no resistance to toxins?

Fingers crossed for the recovery of the latest case which has just been posted, caused they think by maple leaves.
 
I think it is more likely that it is just that AM cases are being more accurately diagnosed these days, and also being more widely publicised on social media. I have definitely heard of a few mysterious pasture deaths over the years which could have actually been AM. In the olden days if a horse collapsed and died in Yorkshire you were unlikely to hear about it in Kent, but now Such tragedies are shared daily on Facebook and forums. I do also think that the number of cases fluctuate year on year, depending on weather conditions. For example if conditions are right for the trees to produce a huge amount of seeds one year, and that coincides with stormy weather that brings a lot of seeds down in one go, then we are likely to see a lot more cases of AM than years when seed production is light and the weather is less stormy.
 
TGM said:
I think it is more likely that it is just that AM cases are being more accurately diagnosed these days, and also being more widely publicised on social media. I have definitely heard of a few mysterious pasture deaths over the years which could have actually been AM. In the olden days if a horse collapsed and died in Yorkshire you were unlikely to hear about it in Kent, but now Such tragedies are shared daily on Facebook and forums. I do also think that the number of cases fluctuate year on year, depending on weather conditions. For example if conditions are right for the trees to produce a huge amount of seeds one year, and that coincides with stormy weather that brings a lot of seeds down in one go, then we are likely to see a lot more cases of AM than years when seed production is light and the weather is less stormy.
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Ah, yes, that might fit. With climate change we seem to be seeing more weather extremes too. Judging by my tack, the current weather is perfect for mould and last week's severe wind would have been perfect for blowing down seeds.
 
I have had the same thoughts a friend and I were saying just the other day how common it has become, I have seen many of the seeds this year compared to the last few years could be that there is an increase?

Or have the trees changed have they become more toxic due to weather or something?

As you have mentioned maybe in previous years it was misdiagnosed?

It is every horse owners nightmare at the moment, My thoughts and sympathy goes out to anyone that has gone through it.
 
I've had people calling me about livery in the past few days and as I said on another thread, their responses were all the same. All were amazed that I am using such big fields and so much grazing, not splitting it into smaller paddocks. I've been around horses all of my walking life, almost 34 years now and I can't remember individual turnout paddocks or over grazed small fields from 20 + years ago. Horses were turned out on good grazing, never over grazed so always grass available, always had access to hedgerows for picking and never ran out of grass or hay.

I do wonder if livery yard owners need to start compensating for the current management trends by removing all Sycamore trees. It's just not fair to put horses into a management that can create ingestion of the seeds.

In addition to that, I have always let my horses pick at hedgerows. They have always loved it and I do wonder if they gain from that in terms of exposure to different things.

I agree with the comment about feed as well, in theory. It would be good to know if there was anything to back it up. Humans are becoming more susceptible to bugs because of over-sterilised environments and not enough exposure to dirt to build up their immune systems. It would be interesting to see how that could relate to horses.
 
I think TGM has pretty much summed it up. Also because it is seasonal & largely confined to a few weeks in Autumn & a few weeks in spring the incidences are highly concentrated & noticeable. Come January & June people who haven't experienced it will hardly give it a thought.
 
new diseases/conditions emerge all the time as bacteria/viruses mutate, environmental conditions change and this happens for human disease as well as animal diseases. Horse management has changed as well and no doubt the type of woodland and planted species has changed too. The first cases of AM were up here in Scotland in the 1970s apparently. It is possible that cases of GS and AM have been confused over the years and the both have similarities (and also important differences) but both seem to be toxin based and both multifactorial. I have been involved with GS for a long time and the cynical part of me thinks that many people didn't care about it because it was not that prevalent down south, although this has changed in recent years. Its been as prevalent up here as AM is now down there. Both diseases are horrendous and everyone should be aware of both and the risk factors for each.

The one important thing known to help protect from either is supplementary feeding. I feed hay all year round, even to my Exmoors, every day without fail whether they need it or not. I am lucky enough to have unfertilised (apart from muck) hill grazing and I am now fortunate that there are no sycamores where we are (although I previously lived their grazing was lined with them and it was a concern).
 
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As posters have already commented, there have been many changes in management. Stable I worked at in the early 80s, a sick horse would be monitored for 24hrs before considering a vet, if it died knackerman came & no- one even considered a pm. As I understand it 24hrs with untreated am, the horse would likely be dead.
Owner's & vets are much more knowledgeable now.
Also our climate, here in the southwest we barely had a frost last winter, its going to be 20 degrees today, sounds like ideal spore breeding & nothing to kill them off. Its bonfire party on Sunday in the village, I'd usually be looking forward to mulled wine warm soup & standing as close to the fire as possible, but night time temps are still around 15. Nothing like a few frosts to kill bugs & we're not getting them.
 
I live in the hills in the north and last winter we had almost no frost as well. There is fungus, mould, lichen and algae growing everywhere here at the moment. Thankfully I have no stables anywhere near, or any trees they can eat anything from. It's a frightening disease!
 
A friend in Southern Ireland lost his horse to it this week.

FWIW, I think GG has a made a very good point about the size and sterile type of grazing available now to some livery yards which is to the detriment of the horse.
 
There has been very recent research linking a particular type of sycamore with AM which has brought this topic to prominence. So it's not a new disease but a possible cause for a poorly understood and under diagnosed disease.

Having had a horse with degenerative muscle problems I can tell you that myopathies in general are poorly understood. This extends to humans - consider how little is known about MS.
 
My mare died three years ago next week. I first read about EAM about three weeks later, and all the symptoms matched, except she was the only one on the yard affected. I've since found out that this isn't unusual. I only knew about it because a couple of race yards in the south west had lost a lot of horses, and of course, they would have had PMs. We didn't know about the sycamore connection then either.

The weather conditions were similar then to how they are now, and though we don't have any sycamores on the yard, there were hundreds of seeds around. I swept them all up as best I could, but had to put them in the bin - I daren't put them on the muckheap because it gets spread and harrowed in during spring and nobody seems to know how long the toxins are volatile for.

I'm still completely paranoid though, and have a mild panic attack if my mare as much as looks in the general direction of her stomach.
 
I was thinking about this myself today.

About 8 years ago I was researching a symptom that my horse had (urine which stained the grass very dark - he's fine now!) and atypical myopathy was one of the conditions which turned up. Believed to be caused by damp, warm conditions, possibly spores in the soil and less likely to affect horses provided with supplementary forage. It didn't fit with my horse's issue and I'd never heard of it, so I moved on to something else. Having had horses for over 20 years and never coming across it, I didn't consider I'd hear of it again.

Within a few years, it's suddenly everywhere.
 
I do wonder if the wet weather we have had has had an effect too?? Are there more toxins present in the soil? At first it was though that it was due to leaf mould. There is a stud near us which has bred TB's for years, they have sycamore trees surrounding their fields and have never had a problem. Again these are big fields with plenty of grazing. Most of our fields have oak trees and one has a sycamore that it on the neighbouring farms land. I am going to approach them about removing it as it hangs over into our field. Needless to say that field is shut off at the moment.

There seems to be so many different things to worry about these days, gone it seems are the days when you just put your horse/pony in a field, fed it chaff and pony nuts in the winter with hay, wormed it, groomed it and were able to take it out for a hack without fear of being mown into.
 
I think is likely that warmer winters where prolonged frost is rare is contributing to the rise of these type of conditions as well as mud fever where fungal agents are contributing to the issue .
Good summer make for happy trees producing loads of seeds as well.
Then you add in the huge number of horses being managed on yards with insufficient over stressed never rested grazing .
Like grass sickness all you can do is keep managing the horses to keep the risk to a minimum and keep your horse in the best yard you can where grazing management is concerned .
 
Last year I did quite a lot of reading on AM. One of the things that turned up was a link with the use of certain wormers. I think it was ivermectin based but I'm not certain. I'm wondering if modern wormers are altering the bacteria in the horse's gut and inhibiting the breakdown of toxins before they can be absorbed.
 
cobgoblin said:
Last year I did quite a lot of reading on AM. One of the things that turned up was a link with the use of certain wormers. I think it was ivermectin based but I'm not certain. I'm wondering if modern wormers are altering the bacteria in the horse's gut and inhibiting the breakdown of toxins before they can be absorbed.
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Ooh, interesting one! I've heard of people resolving gut disease by deliberately infecting themselves with hook worm.




PS just noticed the typo in the heading, predictive text blooper :)
 
With regard to worming I have read it is more common in horses that have not been wormed or vaccinated, so it may be that if a horses is very wormy they do not have a strong enough immune system to cope with the poisons.

This year seems to be particularly bad. There have been about 20 cases in our area over the last two weeks, and the vets have now started issuing warnings however I imagine the number of cases will go down due to increased awareness and the end of the sycamore seed season.

One died on our yard and he was living out in a field with lots of grass so not linked to lack of good grazing. The vets know so little about why some horses get it and others do not. It maybe that some horses build up a resistance to it due to eating a low volume of seeds. Some questions that perhaps need to be asked are

1) Environmental factors
2) Weather
3) Age and condition of horse
4) Worming and vaccination status
5) Any supplementary feeds given
6) How long had the horse been on the pasture - does it only affect horses new to that grazing?

If the number of cases rise I think it will affect business as people will not want their horses on land with sycamore during spring and autumn. Sadly I felt I needed to move yards after a horse died on that yard, it was a long standing yard and horses had been grazed in the paddocks for many years and it had never happened before and hopefully never will again. The other liveries in the field felt that even after the horse died the level of risk was low and I was making a rash decision but I felt I needed to have my pony in a place with no sycamore. Of course I am going to miss my friends and new yard is not so near so pony will be on full livery, he will also be coming in at night when I would prefer him to live out but he will be safe and well cared for. I am though exceptionally lucky as I can afford to move my pony on to another yard out of the area and pay for full livery whereas I know a lot of people do not have so many choices.
 
With reference to the wormers, the research I found was referring to overuse. Not sure if they meant overdosing or too frequent or the use of combination wormers. Am trying to find the paper again!
 
Just seen there is an article in h&h this week about it saying that cases have increased and naming the toxin as hypoglycin-A
 
Yes, that's the nasty stuff. The biggest problem is the level varies between seeds even on the same tree & from year to year. You could have a dozen trees & only 1 branch of 1 tree carry the toxin. To me that suggests that it is something happening to the tree - virus/ fungus /parasite /? - that triggers production of the toxin, but I'm not a botanist & even they don't know. Until we understand the problem it is always going to be hard to know when/where to be concerned & how best to manage it. At least all the publicity makes an early diagnosis more likely & fast access to treatment is they key to survival & the survivors normally make a complete recovery.
 
cptrayes said:
Just seen there is an article in h&h this week about it saying that cases have increased and naming the toxin as hypoglycin-A
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Hypoglycin A is the causative toxin and was known about last year and possibly before.
As Hairycob says, the problem is that it is so variable from seed to seed and from tree to tree.
Hypoglycin A irreversibly blocks some of the enzymes required for normal energy production in muscles, which usually comes from fatty acids. These fatty acids then build up in the muscles. Energy production then has to switch to an anaerobic route, which means releasing glycogen stores. A by product of anaerobic energy production is lactic acid which further damages muscles including respiratory and cardiac muscle.

Eta. The release of large amounts of glycogen stores will result in a high blood sugar initially - which I believe has been found in affected horses. However as glycogen stores are depleted a profound hypoglyceamia will follow. The lactic acid released will upset the normal acid base balance of the body and make matters worse.
 
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cobgoblin said:
Hypoglycin A is the causative toxin and was known about last year and possibly before.
As Hairycob says, the problem is that it is so variable from seed to seed and from tree to tree.
Hypoglycin A irreversibly blocks some of the enzymes required for normal energy production in muscles, which usually comes from fatty acids. These fatty acids then build up in the muscles. Energy production then has to switch to an anaerobic route, which means releasing glycogen stores. A by product of anaerobic energy production is lactic acid which further damages muscles including respiratory and cardiac muscle.

Eta. The release of large amounts of glycogen stores will result in a high blood sugar initially - which I believe has been found in affected horses. However as glycogen stores are depleted a profound hypoglyceamia will follow. The lactic acid released will upset the normal acid base balance of the body and make matters worse.
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So is this toxin present in just the seeds or the leaves too? Is it in the soil that the tree grows in? There are so many questions about this. It is just terrible that there is another thing to try and protect our beloved equines from.
 
Falconers said:
So is this toxin present in just the seeds or the leaves too? Is it in the soil that the tree grows in? There are so many questions about this. It is just terrible that there is another thing to try and protect our beloved equines from.
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I can't find any information about the leaves, I wondered about them too. The toxin is present in the seeds and seedlings but I don't think its in the soil, I would suspect it is manufactured by the tree.
 
cobgoblin said:
I can't find any information about the leaves, I wondered about them too. The toxin is present in the seeds and seedlings but I don't think its in the soil, I would suspect it is manufactured by the tree.
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You seem to have done a bit of research so please excuse me picking at your brains. Have you found what the chemical composition of the toxin is? What does it need to be manufactured? I like to try and understand what goes on (if possible) if any of mine are ill or what causes it.

Sorry, I was being very lazy, I could have course gone and done a search myself!! Pootles off to do just that.............................
 
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Falconers - the big problem is there are a lot of questions & nobody knows the answers to most of them.

We know that hypoglycin A can be found in the seeds & the young seedlings of sycamore (probably the cotyledon leaves rather than the true leaves).
We know it isn't present in all seeds, just some & that huge variations can occur between the seeds on just one tree.
We don't know whether other acers are a risk.
We don't know whether the toxin can leach into the soil.
We don't know why some seeds produce the toxin & others don't.
We don't know why some horses on the same pasture are unaffected.
There isn't an established treatment protocol, just give fluids, monitor & support with a list of "this has worked for some horses" & "you could try this". Even the best painkillers & muscle relaxants to use are not established as they can lead to other problems with this condition e.g using muscle relaxants may help reduce the damage or reduce the ability of the horse to remain standing & what will happen is very much suck it & see. Pain killers can reduce temp & horses with AM tend to be hyperthermic so you want to warm them up.
There isn't an established rehab protocol - just advice to take things slowly & see how it goes. Maybe I have taken things slower than necessary, maybe not.

I have seen loads of things suggested as risk factors & too often the impression is given that only young or old, unfit, underweight horses on poor grazing are affected. There have been so many cases this year where that has not applied. My own 2 were both fit ( ridden 5 times per week - schooling, long hacks etc), 8 & 15, ideal weight, small additional feed of speedibeet + mineral supp & linseed, the 2nd was also being fed haylage. The grass was decent & growing fast (it was April), I was worried about them putting on weight. They were both on an FEC & targeted worming programme, so neither under or over wormed, they had a salt lick in the field & a self filling water container that had been cleaned before they went into the field. They had a field shelter as well as good shade from hedges & a large ash tree. Apart from being cobs they were the complete opposite of any risk profile I have seen. So many questions, so many what ifs.

There is little funding available for research. The University of Liege have an appeal on their website & I would urge those concerned to make a donation. I would also urge anybody who has suffered a case to log it on their website & get their vet to as well (different questions). I am trying to arrange a fund raiser for next year - hopefully a sponsored ride next September.

The absolute irony is that when we got the 2nd to the vet he commented on his condition & how nice it is to see a cob that isn't overweight but nice & muscly & then said "it's a shame is I think this is the one time it would help him to be fat".
 
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I saw that other horses on a yard where one horse had died had had blood tests - that implies there is possibly a level of poisoning without signs/ symptoms. If so wouldnt routine screening be worthwhile for horses at risk?

My mare is on a yard where every single paddock, and they are all small and well grazed, is surrounded by sycamores. Horses are in at night and well fed, but I am worried about her of course.

Might give the vets a call tomorrow but any thoughts now?
 
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