Throat problems -Misconceptions!.


Equine Breathing Problems:

Some Current Perceptions and   Misconceptions.

   Tom Ahern BVSc MRCVS               18/6/2000

It is with great pride that I can report that in lieu of an enormous amount of combined research and development in recent years, the Equine Veterinary Profession can boast many significant advances in the field of respiratory (breathing) medicine and surgery.

It is with equal dismay that one must also report that  much of the knowledge acquired has not yet filtered through to the members of the industry (Racing Industry) that it serves.

To illustrate this point I will discuss just a few of the more common comments that I often hear from respectable persons in the racing industry.These same comments are heard in most racing countries around the world.

Often I will hear the comment that a particular horse is ‘Broken Winded’ or ‘Touched in the wind’, or a ‘Roarer’ . These colloquial terms have generally been used in reference to horses with significant degrees of, weakness through to complete paralysis, of one side of the larynx (left). The larynx is the equivalent of our voice box and sits at the top of the windpipe. Now I purposely used the word ‘generally’ because it is not unusual for people to lump some 35 different types of ‘throat problems’ under the same banner ‘broken winded’ . This would be akin to a post race report stating that ‘two horses pulled up with ‘bone problems’ . In reality one was suffering from ‘shin soreness’ (requiring rest) whilst the other had multiple fractures of the shoulder bone (scapular) and was euthanased.

This example may sound a little ridiculous but it is only as ridiculous as stating that several horses failed to run on in a race because of a ‘wind / breathing problem’.

More correctly ‘Was the problem because of laryngeal weakness, pharyngeal collapse, epiglottic fold collapse, epiglottic entrapment, gutteral pouch infection.....etc (and remember there are up to 35 of these)?

Next the often heard comment “I won’t breed from this mare / colt because it had / has a breathing problem”.

Question.  What breathing problem?.... and

                    Why?..... Oh!..... “because it will pass the problem on to its progeny”.

Answer.  Well if the horse has a significant degree of ‘laryngeal weakness’ then there may be a case for not breeding as an hereditary predisposition has certainly been demonstrated in many instances. However one must also be aware that there are other causes of laryngeal weakness which do not have any  hereditary link. These should be ruled out first.

Question.  What about breeding and the other 20 to 25  throat conditions / breathing problems ?

Answer.    None of these have been demonstrated as having an hereditary link.

Thus to exclude these from breeding is akin to telling a champion rugby player , who had a meniscal / cartilage knee problem, that  he should not be used to breed athletic sons or if he does then they should not be permitted to play competative rugby ( register with a rugby code).

Similarly one might hear... “ I heard that that horse had ‘throat surgery’ so I won’t breed my mare to it!”  If the horse had surgery for significant laryngeal weakness then there may be sound reason for this statement.

N.B.At the same time many very high rated horses have been bred from stallions with laryngeal hemiplegia(roarers).

If however the horse had surgery for one of the many other conditions then this statement or decision is  ridiculous and possibly defaming ( of the Stallion / mare). This would be similar to a woman not marrying our champion rugby player because as a result of having surgery on his knee it is implied that he may well have ‘abnormal’ progeny.

Another often heard comment is that  “my  horse had throat surgery” which is similar to hearing that someone has had ‘Heart surgery’.

In the later situation one would ask did this person have a coronary graft, bypass surgery, valve replacement, heart transplant .... etc. As you can see the initial term ‘heart surgery’ was rather vague, but then again only as vague as it is to use the term ‘throat surgery’. There are currently some 20 different procedures being performed on horses throats and the number is growing annualy.

Next time you hear this comment it may be worth investigating a little further .This would be particularly relevant if you are contemplating surgery on your own horse or are breeding to a horse that has had a ‘throat procedure’.

Your question... “Which surgery?”!

Another often heard comment after a race.

Question .Trainer,  “ did he make any noise during or after the race?” Jockey, “No!”   Trainer, “So he doesn’t have a breathing problem!”

Given that recent studies have demonstrated that at least 20% of horses (1 in 5) that choke ( experience different forms of pharyngeal collapse/DDSP in gallops or racing ) present with no history of abnormal noises, it makes this method of elimination (on its own) rather ridiculus.

The next comment is often more confusing than necessarily incorrect.  ”I had my horse scoped (in a stall) and the vet could see nothing wrong.” Too often the conclusion (owner/trainer) given this comment is that the horse does not have a breathing problem! Have you ever looked at a person standing by a river and made the comment that “they appear unable to swim”. They may well be unable to swim but does your one observation (that they are not swimming) prove this beyond reasonable doubt.  No!

Similarly there are numerous breathing anomalies that can only be fully investigated by examinations carried out during exercising, or at the least with the collection and collation of a comprehensive history.  i.e. Many horses with significant breathing problems ‘appear normal’ at rest.

And another “My horse has a paralysed palate, or elongated palate”. Paralysis of the soft palate is rare but can occur. Elongation is a ridiculous term ( a little like saying that people are elongated in comparison to turtles). All equine palates are elongated structures.

And what about breeding palate horses!

The vast majority of equine soft palate , pharyngeal, choking....  problems are an inappropriate occurrence (similar to putting ones arm around royalty), the frequency of which increases with increasing exercise demand. This means that at least one factor in a ‘multi factorial condition’ (pharyngeal dysfunction) is that the faster the horse goes or the quicker it accelerates, the more likely it is that choke or pharyngeal collapse will occur! ..

So if we are serious about reducing the incidence of this problem then we should firstly exclude all the fast horses from future breeding programs. 

And also.........    referring back to our rugby champion, it should be obvious to all that the incidence of knee injuries / problems at an International level of competition is higher than at local village competition. Why? because the top grade players apply more pressure to their anatomy - play harder. So to significantly reduce knee trauma in rugby players we should only allow low grade teams to compete and thence disband international competition.! Similarly have ‘slow horse’ races!

And lastly!..... “Just give him time in the paddock and he should grow out of that problem”. This comment is often made of pharyngeal dysfunction, DDSP (Dorsal Displacement of The soft Palate),  choking...etc and particularly in reference to 2 year olds. Unfortunately in 15 years of questioning leading international trainers and others, I have been unable to find one who agreed with this comment. More often the comment is that even though these horses may make less or no noises after a long rest they are also invariably in the main disappointing!  Remember it is race / gallop performance and not ‘amount of noise’  that creates winners and losers.

Is all this sounding a little ridiculous?

Then I’m sure you are beginning to appreciate how disappointed myself and others of my profession feel, when despite the many advances being made in this field, the Industry itself often appears ‘blissfully unaware’.  

Happy racing!