Comments on: Measuring Great Hearts

By: wayno@oz

wayno@oz — Thu, 02 Apr 2009 06:14:21 +0000

Awesome article again! I have a slightly enlarged heart, passed down from my mother who in turn recieved this gentic trait from her mother. At 16 i had an abcess on the inside of my spine that ruptured and caused blood poisoning. I was told by my treating doctor that the only reason i survived was due to my larger heart. Again at 20 i was stabbed in the leg, severin g my femoral artery and once again(surprise surprise) i only survived becuase of the hearts ability to continue pumping under extreme stress ( I had lost over 50% of my blood and should have been dead) My doctor told me that, in 25 years of medicine, i was the only bona-fide miracle he had witnessed. Unfortunitly there is a price to pay for this as my mother now has a pacemaker, as it seems her heart is a little worn out and i have been told that i can expect the same. During my teenage years though i was certainly the faster, better, stronger one of my friends and family and was able to achieve moderate success in the sporting field. I’m no medical scientist but i believe there is a correlation between heart size and physical performance.

By: Mirage_GSM

Mirage_GSM — Fri, 27 Jun 2008 06:57:02 +0000

[quote]horsesarefriends said: “Hi, everyone.

Anyway, I find it peculiar that there should not be a way to tell a horse’s heart size pre-mortem. Can’t you just X-Ray them?

By: Dropbear

Dropbear — Sat, 29 Mar 2008 08:47:57 +0000

[quote]donlaudanny said: “I’m surprised that racehorses live so long…….From what my jockey friend has told me, horses are typically considered old past 10 yrs…..”[/quote]
In the racing context horses are considered old when the reach 10 – in fact most finish racing by 8 years, however hurdlers and steeple chasers peak around this age (I think..). But this is really the only equestrian sport where horses are retired at such a young age. Many great horses have won Olympic standard competitions between 12 -17 years of age – many former race horses have gone on to successful careers as eventers and the like. Barring any sever illnesses, most horses, racehorses included, live happy lives being ridden past 25 and die over 30.

By: tarteauxpommes

tarteauxpommes — Thu, 13 Sep 2007 22:34:57 +0000

Racehorses have really cool names. Like Eclipse and Secretariat and Citation. Those are AWESOME names.

By: Scharneeigh

Scharneeigh — Thu, 26 Oct 2006 03:58:32 +0000

Asshe said:

"However I do remember reading that one of the males with an unusually large heart died of a heart attack. But with just one case this certainly doesn't indicate any relation between large hearts and being at greater risk of heart disease etc. Sorry but I can't remember where I read this info…"

The New Zealand (yes, the Aussies did steal him, just like lamingtons, Russell Crow, and myself) horse, Phar Lap, who had an incredibly large heart (I've seen it), was beleived to have died of a heart attack, although now his death was believed to be caused by ingesting arsenic. Still, maybe having a large heart is good in the short term, but just can't keep up aftera while. Hmm...

By: horsesarefriends

horsesarefriends — Sat, 30 Sep 2006 20:12:15 +0000

Hi, everyone.

There is a big issue for horse lovers before the Senate right now. Three foreign-owned horse slaughter plants here in the USA are killing American horses to sell to diners in Belgium, France and Japan. They kill the horses, harvest the meat, and then ship it overseas. There is a bill before the Senate right now to ban this practice in all 50 states.
Me and some friends are asking people to send an email to their senators asking them to push this bill through and vote to end horse slaughtering. The bill has already passed the US House of Representatives and this is the last hurdle before it goes to the President for his signature.
A common misperception is that the horses are old or sick – not true. Many are under 2 years old and healthy, and are sold simply for money.
Here’s how you can help – everyone needs to contact their senators and indicate they don’t want our horses dying to feed other countries.
Go to http://www.congress.org/congressorg/home/ and type in your zip code. Send an email to both of your US senators and tell them to stop this terrible practice. The vote is coming before the Senate next week so please do it NOW! :-) Thanks!!!
And here is a blog that we set up so you can read more information about it:
http://www.horsesarefriendsnotfood.com
:-) Thanks!!!

By: Tirebiter

Tirebiter — Wed, 31 May 2006 19:28:45 +0000

It’s a little curious to me that in the last 200 years the average thoroughbred heart size has increased 42% but the average speed of the horses has varied within a range of less than 15% in the last hundred years ( I could not find 200 years worth of time and speed statistics). For example, since 1900 the time for the 1 ¼ mile Kentucky Derby has varied between the record low set by Secretariat in 1973 of 1:59 2/5 seconds and a high of 2:15 1/5 in 1908 (on a muddy track). In the past 33 years since Secretariat’s record the variance has been between 1:59 and only 2:05 or less than 6 seconds. I think I would reconsider the correlation that was suggested in the article.

http://www.kentuckyderby.com/2006/derby_history/derby_statistics/

By: donlaudanny

donlaudanny — Mon, 29 May 2006 13:04:40 +0000

I'm surprised that racehorses live so long. As a biologist, it's widely understood that growth hormone accelerates aging. Larger dogs die sooner than smaller dogs, and larger individuals tend to die sooner than smaller individuals from age related causes in the same species. Thoroughbreds definitely fit in on the larger side of the curve. From what my jockey friend has told me, horses are typically considered old past 10 yrs. Understandably, racehorses will likely receive better care due to the nature of their owners and may be allowed to live past the point where draft horses are put down. But if what you say is true, then I retract my statement.

About the steroids/GH statement. I have never seen a source besides you mention that it is NOT universal in racing. Of course steroids are beneficial, if they weren't, then they wouldn't be taken! Steroids and GH speed up recovery rates and can heal microinjuries that would otherwise result in serious problems. But GH does increase heart size, so part of the 42% increase might come from GH use rather than selection forces.

The 42% were taken from the 6 lbs and 8.5 lbs given in the article. If that's not true, then the statistic won't hold. That doesn't change the fact that the rate of change in thoroughbreds is astonishingly fast. It's SUPPOSED to be. That's what artificial selection (breeding and pedigrees) is.

The way a thoroughbred is engineered IS very different. If you look at the VO2 max as well as the oxygen dissasociation curves, you find conditions which are very much outside the regular mamillian physiological range. One example is that their lungs are horribly underengineered for the amount of oxygen that the rest of the system can utilize. This is because races are relatively short and lung capacity doesn't matter as much, so the selection pressure for the rest of the system, from the cardiovascular to the muscles have been much greater. It doesn't matter if the lungs bleed, as long as the horse wins the race and has time to recover before the next one.