Spinoff: Cardio-pulmonary-aneurysm issues and eventing

[HorsesinHaiti]

Several people have suggested we need to split the discussion of cardio, pulmonary, and aneurysm issues off from the Kingpin thread so that thread can be about Kingpin. I'll get it started.

[deltawave]

There have been quite a lot of these in the past, but it's worth resuscitating the topic. Until the necropsy results are officially released, (not sure I've seen anything more than preliminary speculation, but I'm not right in the loop) we're sort of speculating.

It's very, very, very important to be precise when talking about these catastrophic events. I'm so glad the OP didn't say "heart attack"! I'm not sure "aneurysm" is the right term, either, but spontaneous rupture of the great vessels seems to happen often enough to bring the term up--it's a close enough description except it gives the impression that this sort of thing can be picked up ahead of time, like an aneurysm can. As far as I'm aware, that's very much NOT the case, although USEA is trying to get research off the ground to do some screening imaging on elite event horses to try and gather some prospective data.

The horses that have died suddenly in recent years seem to fall into 3 broad categories: EIPH, aortic rupture in the chest/near the heart, and abdominal vessel rupture. Three huge, broad, and possibly very distinct categories, and they all may have different "proximate causes".

I wish I could take 5 years off and work on this and nothing else.

[HorsesinHaiti]

Jump racing and steeplechasing have had similar issues over the years, correct? Best Mate (and perhaps but not sure Dawn Run??) are just two names that come to mind, though I know there have been many more. I'm just starting internet searches, but some of the research has been started. Who has info/links? Please post them here.

[HorsesinHaiti]

First threads I find on a COTH search:

http://www.chronicleforums.com/Forum...d.php?t=200019

http://www.chronicleforums.com/Forum...ight=anyeurism


The end of this thread has info on several research efforts: does anyone have more info on how these are going?

[Drvmb1ggl3]

Originally Posted by HorsesinHaiti

Jump racing and steeplechasing have had similar issues over the years, correct? Best Mate (and perhaps but not sure Dawn Run??) are just two names that come to mind, though I know there have been many more. I'm just starting internet searches, but some of the research has been started. Who has info/links? Please post them here.

Dawn Run broke her neck.

Best Mate did die from a heart attack, but it was post race, as was the recent case with Exotic Dancer.

[ideayoda]

Many aneurysms are weakening in the walls of the vessels because of (previous) worm damage made worse by the huge blood volumne being drawn on by a horses huge heart really pushing, but the particular place it blew out (with exertion of a jump) will be key. With so many deaths, it calls into question the extreme speed vs extreme fitness. With the long format the need for extreme fitness was a necessity, now there is extreme speed w/o that underpinning. Long distance horses go those long distances but at a slow speed, sprinters (even milers) have extreme speed but for a shorter time. Eventing requires jumping efforts at speed as well. Since horse deaths (in such a way) were far fewer at a top level in times past where pipe openers and more flat work were part of the program, it is just logical

[HorsesinHaiti]

Originally Posted by Drvmb1ggl3

Dawn Run broke her neck.

Best Mate did die from a heart attack, but it was post race, as was the recent case with Exotic Dancer.

Best mate was pulled up in his final race and died coming off fat the end of a big competition effort- kind of like a recent case discussed here. There was some stalk that Dawn Run fell due to a cardiovascular issue taking her down, but I'm not finding a definitive report yet though I'm googling for one.

Point is, we are discussing this issue yet again. COTHers can give us a long list of horses lost to cardiovascular and I'm sure they will. Eventers would all love to find a way to keep the list from growing.

So here's a space to hold that discussion. Please cross-link to anything relevant and discuss away.

[Bensmom]

Though it has been discussed in previous threads that are linked here -- deltawave, will you explain my statement on the other thread that horses do not have "heart attacks" the way that we use the term in people?

I know that is correct, but a cardiologist can explain it MUCH better than I can!

libby

[deltawave]

Gladly.

A heart attack is really a very specific and precise term (really we ought to say "myocardial infarction" but even I don't bother much of the time) that means one of the coronary arteries, which supply blood to the heart muscle itself, has become occluded. Usually this is because of a ruptured "plaque" with a blood clot forming on top of it, suddenly making blood flow downstream go to "zero". Since horses don't get the disease (atherosclerosis) that causes plaque or "blockages", they don't have "heart attacks". Using the term improperly or incorrectly is perfectly OK if you're a layperson, I suppose, but it's not that difficult to be precise, and it makes for a LOT less confusion.

The term "aneurysm" also is fairly precise, and means a weakness of an artery wall that causes ballooning or bulging. Everyone knows this. But what seems to happen to horses, as far as I'm aware, is that the artery just suddenly ruptures, and there is no indication beforehand that there has been a weak spot or a structural bulging. That doesn't mean they aren't there, but the literature doesn't really clarify it. Obviously if a performance horse had a big aneurysm sitting in their aorta, there would be a powerful recommendation for the horse to NOT compete. But it appears that these vessels can rupture without any pre-existing signs of weakness, which of course is scary and simply BEGS for us to be able to know more and identify these animals beforehand.

My own theory, supported by not much at all, is that like humans, horses can sometimes have connective tissue defects that predispose them to this sort of thing. Sort of like what John Ritter, the actor had--he didn't have an aneurysm per se, but died suddenly of an aortic dissection (a tear in the lining) which is CLOSE but not the same thing and might not have been detectable ahead of time.

[IBWmassage]

have there been any studies that involve digital imaging of horses' circulatory system when stressed/at work? Is it possible?

[deltawave]

Stress echo can be done and there is a fairly good body of research on that in racing, but it's an incomplete body of work. It would also be very difficult, if not impossible, to replicate the demands of XC on a treadmill. Extrapolating a steady gallop to the demands of XC is problematic.

[TampaBayEquine]

For those who are interested...
There is some research currently going on regarding EIPH . This is from the Grayson-Jockey Club Research Foundation...(You can also make a donation via their website.) Have not heard the specific cause of death of Kingpin yet, but since we are revisiting this issue, I thought this may be interesting for some folks.


http://www.grayson-jockeyclub.org/gr....asp?section=4



"Mapping Occlusion of Veins in EIPH
Dr. Fred Derksen, Michigan State University. Second year..

This is another approach in the series of attempts to understand fully why so many horses experience bleeding (Exercise Induced Pulmonary Hemorrhage: EIPH) in the lungs as a result of high exercise. In past research funded by the foundation, this research team discovered scarring around blood vessels, which obstructs the veins and causes back-up in the lungs and rupture of its small blood vessels. This new project is designed to determine the location and extent of vein scarring in the lungs and compare it to horses that have not raced, also relating the location of the scarring with the location of the bleeding. Another aspect will be investigating why vein scarring occurs by studying molecules in the vein walls that signal scarring to occur. This project has the potential to guide research in a new direction for effective prevention and/or treatment of a widespread occurrence. "

[Ghazzu]

Originally Posted by deltawave

My own theory, supported by not much at all, is that like humans, horses can sometimes have connective tissue defects that predispose them to this sort of thing. Sort of like what John Ritter, the actor had--he didn't have an aneurysm per se, but died suddenly of an aortic dissection (a tear in the lining) which is CLOSE but not the same thing and might not have been detectable ahead of time.

I expect you're right.
There has been some mention of a higher incidence than might be expected in one breed (since I can't put my hands on the citation at present I will forbear mentioning the breed), but the defect isn't caused by exertion.
Exertion stresses the defect, sometimes beyond its limit.

[LLDM]

Originally Posted by deltawave

My own theory, supported by not much at all, is that like humans, horses can sometimes have connective tissue defects that predispose them to this sort of thing. Sort of like what John Ritter, the actor had--he didn't have an aneurysm per se, but died suddenly of an aortic dissection (a tear in the lining) which is CLOSE but not the same thing and might not have been detectable ahead of time.

Originally Posted by Ghazzu

I expect you're right.
There has been some mention of a higher incidence than might be expected in one breed (since I can't put my hands on the citation at present I will forbear mentioning the breed), but the defect isn't caused by exertion.
Exertion stresses the defect, sometimes beyond its limit.

Not to argue with medical experts like you and Deltawave - but... If it was the case that there was an existing connective tissue defect, why/how can these horses compete at these levels for years before they have such an incident? I mean wouldn't that indicate that such a defect was developed over time, maybe through repeated stress (like the idea of a weakening frangible pin)? And yes, I am looking more at the physics of it, rather than the biology of it - as that is what I am more familiar with.

Also, if it is a process that develops, it is likely to be a process that is preventable or reversible once we understand it. Or maybe at least identifiable and manageable so that we might be able to retire these horses before they hit the wall so to speak.

Just thinking/pondering out loud.

SCFarm

[Ghazzu]

Originally Posted by LLDM

I mean wouldn't that indicate that such a defect was developed over time, maybe through repeated stress (like the idea of a weakening frangible pin)? And yes, I am looking more at the physics of it, rather than the biology of it - as that is what I am more familiar with.

Looking at it from a physics standpoint is probably pretty appropriate.
I think the frangible pin analogy may be apt.

As for underlying etiology--total speculation here--in some cases, possibly a genetic predisposition, in some, a possible developmental issues, in others it could be verminous damage, etc. There's a nutritional component to vascular disease in the horse as well (copper deficiency), though I'd put that pretty far down the list with a well-maintained athlete...

Also, if it is a process that develops, it is likely to be a process that is preventable or reversible once we understand it. Or maybe at least identifiable and manageable so that we might be able to retire these horses before they hit the wall so to speak.

Well, if we could identify it before system failure, we might be able to, as you say, manage it. At least not send them x-c. Though a retiree might drop dead galloping in the pasture.

[roanoke2010]

Looking at the last few years especially since the new XC format there have been an increase in the amount of deaths on XC especially at the upper levels. There is being research being done to find out why. My trainer has been one of the leading people in doing this and has been working with USEA. I was an intern at Garmin last year, and we were specifically trying to get Garmin to team up with us on the research by having them make a forerunner that was adaptable with horses. The forerunner is what runners use to check their heart rate and speed as they run. All of this can be logged onto a computer so you can chart it. They have been using this system on horses running XC as a trial to try to put data together and look at the horses heart rate and speed as they try to make time and hit specific areas and distances on the courses as well as what their speed/rate is approaching and landing after fences. We can't ignore the fact that in recent years the increase in deaths and falls is much greater than what it was a decade ago. There has to be some correlation with what we are expecting out of horses these days compared to what it was years ago. It just seems like every time I turn around there has been another death or serious injury on XC. Granted its not always XC though, I was at Maui Jim last year when a young riders horse died in the dressage ring. I also had a horse die on me while I was lounging him from an anuerism (sp?). Its an awful thing to happen and it hurt me more than anything to see it and for a long time I couldn't get over it. This proves there are freak deaths all the time that don't happen for a specific cause but don't you think that when the death rate is much higher for XC than the other disciplines that there is a reason for it? At some point us eventers need to look back and figure out what we have changed to bring this increase about. Every death can't just be blamed for natural causes, its becoming more and more apparent that this can't be our reasoning.....

My deepest condolences go out to Mike Winters and his team. Its a horrible thing that happened but at some point we need to look back and see if we can help prevent some of this from occuring.

[La Gringa]

I wonder if it's an accumulative effect of the strenuous training and exertion put on the heart when training for this level of event? Maybe it puts too much strain on the heart tissues and eventually they fail?

Not a doctor here.. just me thinking about it.

Maybe the strain is just too much? Kingpin was a fit well trained horse, but he has been doing this at this level for awhile now. Maybe his heart just got weakened and pumped too hard over the years from the strain?

This is of course saying that if the report comes back that it was indeed his heart that was the issue.

[La Gringa]

Originally Posted by Ghazzu

Looking at it from a physics standpoint is probably pretty appropriate.
I think the frangible pin analogy may be apt.

As for underlying etiology--total speculation here--in some cases, possibly a genetic predisposition, in some, a possible developmental issues, in others it could be verminous damage, etc. There's a nutritional component to vascular disease in the horse as well (copper deficiency), though I'd put that pretty far down the list with a well-maintained athlete...



Well, if we could identify it before system failure, we might be able to, as you say, manage it. At least not send them x-c. Though a retiree might drop dead galloping in the pasture.

Maybe it's a combination of things as you say here. A process of evaluating the heart of the horses before events like this.. maybe would be the key. For people competing and training at this level, maybe a routine check of the heart function and health would be in order. Is there even a way to do this in horses?

I wonder also, if as in people, heart conditions can be passed on genetically in bloodlines? I am sure some conditions could.. just like arrythmias and other conditions in people can.

[IFG]

I have seen CT images of dissected aortas in humans. Cannot remember if the pics were picked up incidentally or because the patients had symptoms.

Is it possible that the advent of the short format has facilitated participation of more horses at the upper levels without the vet-monitored testing at the lower levels (Prelim and Intermediate)? Could such stress-testing at the lower levels, and during Phases A,B, and C at the traditional 3-day might eliminate these horses before they suffered catastrophic consequences at the **** level?

[Ajierene]

Originally Posted by Ghazzu

Looking at it from a physics standpoint is probably pretty appropriate.
I think the frangible pin analogy may be apt.

As for underlying etiology--total speculation here--in some cases, possibly a genetic predisposition, in some, a possible developmental issues, in others it could be verminous damage, etc. There's a nutritional component to vascular disease in the horse as well (copper deficiency), though I'd put that pretty far down the list with a well-maintained athlete...



Well, if we could identify it before system failure, we might be able to, as you say, manage it. At least not send them x-c. Though a retiree might drop dead galloping in the pasture.

I think the frangible pin analogy is very apt.

Take two pins - made from the same machine. One is made of aluminum, one of stainless steel. Since they were made from the same machine, they both have the same exact defect of say a crack at the halfway point.

Put them in a jump - the aluminum one will break a lot sooner than the steel one.

Take that aluminum one and put it on a shelf and keep using that steel one, or better yet, use the aluminum one on a jump that hardly ever gets hit and the steel one on an often hit jump and the aluminum one will last longer.

It is the same with a connective tissue defect. When it is spotted, preventative measures can be taken. Maybe the 4 star horse can do a total of four events a year without incident, but cannot run every month like a healthier 4 star horse. Maybe that horse with the defect should not be pushed passed Prelim, Training, what have you. That is where some of the difference may lay - in how fast a horse is moved up the levels, what their other training is and how they are conditioned, etc.

With a change in how the game is played, there may need to be a change in how the players are conditioned. Or, possibly the opposite. The game changed so people stopped conditioning their horses as much and they really should have stuck to the original plan. Perhaps conditions such as these were not noticed before because horses ran less, were retired earlier, or their conditioning schedule was different. I am sure horses died of aneurysms in eventing before, but the numbers are difficult to figure out because there were not as many records of the exact whys in previous decades. I do wish there was a way we could look back and get more insight into differences, if any, between then and now.