A NEW APPROACH TO  DIAGNOSING BREATHING PROBLEMS IN RACEHORSES -

YOUR INPUT ( trainer & rider) IS ESSENTIAL!

There are broadly speaking two areas of the throat that can dysfunction. Firstly the 'larynx' which is the gate mechanism at the entrance to the windpipe and secondly the 'pharynx' an elongated cave like structure( collapsable) through which air passes from the nasal passages to reach the larynx and windpipe. The soft palate forms the floor of this pharyngeal cave.


30 YEARS AGO 66% of equine breathing problems were associated with weakness or hemi-paraslysis of the larynx.

The other 34% were mostly pharyngeal ( palate, DDSP choke.. etc).

Laryngeal problems were diagnosed when firstly an abnormal noise was reported and secondly scoping revealed a weakened or paralysed most often left side of the larynx. The pharyngeal problems were always more difficult diagnostically and were most often loosely diagnosed after hearing a horse gurgle and in the absence of a laryngeal problem.


TODAY the latest research has the traditional laryngeal problems accounting for just 34% of cases of abnormal breathing whilst  66% in some way involve the pharynx. A COMPLETE REVERSAL!

The other ‘revelation’ from this and other more recent research is that there are a considerable number of breathing problem horses that don’t produce abnormal breathing noises . To further complicate the issue scoping these horses at rest often results in reports such as “I can’t see anything abnormal”,“  or “The pharynx is just a bit inflamed!”. This is because most pharyngeal problems are dynamic and only occur when the horses respiratory system is under pressure (races and hard work). A bit like snoring only happens when your asleep not whilst one is sitting in a chair having dinner!


Then how were these additional cases discovered?


Answer -   Well eventually for no particular reason someone decided to investigate horses with previously unsolved symptomless’ reduced or poor performance problems on a high speed treadmill and discovered to their surprise that dynamic airway blockages were quite common in these apparently ‘symptomless' horses. These horses of course made no noises!


In addition there are some  breathing problems that don’t show up on a treadmill!

Why? because a treadmill is not a racecourse and therefore insufficient pressure may be generated to trigger the underling dysfunction. Also there are horses that will  refuse to put themselves under pressure on a treadmill (as they do on the racecourse) i.e. DON’T TRY!.


In conclusion this means that right now up to 30% of horses with pharyngeal breathing problems are probably not being diagnosed because they are.....


            (i)  not making a noise     and

            (ii) have normal looking throats when scoped. 


But if my horse makes NO NOISE and  SCOPED NORMAL.........

then how do I know if it’s 'under-pefoming' is due to one of these 'pharyngeal breathing problems'.


Answer -   Read on!


A HISTORY OF BREATHING PROBLEMS.


Veterinarians including some of those who use highspeed treadmill endoscopy now agree that when dealing with 'pharyngeal breathing problems' the most important part of the diagnostic protocol is the HISTORY. Traditional standing endoscopy (SCOPE) is used more as part of an elimination process and in preference where indicated horses may be scoped at exercise on a treadmill (TREADMILL SCOPE). More recently ‘over ground’ scoping ( a small scope is used whilst the horse is riddden and galloped on a gallop or racetrack) has been utilised. This later method of scoping is much more likely to demonstrate a dysfunction.


This means that to a large extent the ability to diagnose pharyngeal breathing problems is reliant  on the ‘powers of observation’ of trainers and riders, often referred to as a good test of ‘HORSEMANSHIP’.  The ‘non horseman’ can often be overheard referring to a horse as a ‘dog’ or ‘squib’. A ‘horseman’ is well aware that a horse which is reluctant to perform at its best has in 99% of cases un ‘underlying problem’. The CHALLENGE is then to diagnose isolate and treat the problem or problems.


What sort of abnormal occurrences or symptoms are we looking for to put together a history of PHARYNGEAL breathing problems?


Answer - The following! ( N.B - different horses will exhibit different groups of the following symptoms. Some may only exhibit one or two changes and are less obvious whilst others show multiple changes.)



NOISES -

1) a ‘thick sound’ or noise on breathing in and out. The ‘thick winded’ horse.

2)  rasping noise when ‘held up’ in work,

3) gurgles, These are often heard intermittently. May be more evident early in training and in young horses. Be careful though in assuming that if the noises go away then the problem has also gone. Horses often downgrade their effort so that noises are no longer evident & their race form likewise is downgraded!

4) breath holding or reduction in breathing effort when under pressure,

5)  hollow inspiratory noise or air through the mouth when breathing in,


ABNORMAL POST RACE /  EXERCISE RECOVERY

1) some  blow very little and appear to have ‘not tried’.

2) some seem to always blow too much after a race or hard work. Can’t get them fit!

3) some blow for long periods after a race or ‘pant’ for long periods. May well be experiencing a degree of bronchospasm ‘tight chest’ as a result of secondary lung damage or sensitivity.

4) Some of the more extreme will vary from violent after the race to physically collapsing in the return enclosure.

5)abnormal cardiac rhythms are not uncommon after partial asphyxiation (choke) seemingly due to a lack of oxygen to the heart and associated vascular acidosis. It is conceivable that chronic airways problems  may lead to permanent performance limiting cardiac dysfunction. If there is a concern then further cardiac assessments should be performed.


BEHAVIOURAL CHANGES - are mostly race & track associated i.e. relaxed at home on regular work days ( pacework only), but then are....

1) nervousness race day - shakes and sweats when led to float, at pre-race shampoo,or other race day rituals.

2) racecourse nervous , apprehensive and in the more deliberate animals ‘aggressive’ kicking out and pulling away in the enclosure.

3) reluctant to go onto the racetrack

4) reluctant to enter the starting gates.  May stay in the gates and refuse to run ( unusual).

5) may get upset in float on the way to the races but is OK’ on the way home!

6) some as described above under poor recovery can be very aggressive after a race.


WORK RELATED BEHAVIOURAL CHANGES

1)  mouth open / pulling

2) tendency to overwork, rush, more an attitude to wanting to 'get it over and done with'!

3) Happier getting off the track (coming home) than going on to it (going out to work).

4) Refuses to work at any reasonable pace. Reluctant worker.


Therefore. - a horse which relaxes in its work and ‘goes to sleep’ in the float on the way to the races and in the stall before a race is less likely to have a significant breathing problem.


SWIMMING -

1) can be poor swimmers - climb rather than stretched out when swimming.

2) may be reluctant to swim at all.


POOR PERFORMANCE

1) 600 meter wonder - goes like the wind for 600m’s then stops like a ‘pricked balloon’!

2) travels well in running then when asked for an effort , goes for a stride or two before reducing effort often with the head coming up and stride reduced.

3) goes well but just doesn’t ‘get home’ the last furlong or last 200-100 meters.

Therefore- a horse which is doing its best work over the last furlong of a race is less likely to have a significant breathing problem.


CHRONIC LUNG PROBLEMS

Horses with breathing( throat) problems often cheat a little by taking air through their mouth as well as their nose. This seems like a sensible solution to reduced nasal air supply( breathing problems) however air acquired by this ‘emergency route’ is often ‘dirty’ air. This is because the air being drawn through the mouth can take saliva, feed particles and bacteria with it and deposit these in the airways ( windpipe & lungs). These foreign particles then contribute to lung disease including inflammation, infections and bleeding. Inflammation and infections often recur at times of maximum racing and training stress when horses are more likely to require that extra or emergency air.

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IF MY HORSE IS EXHIBITING SOME OF THE ABOVE SYMPTOMS AND IS UNDER PERFORMING WHAT DO I DO NEXT?


Make your stable veterinarian aware of the symptoms and see if he or she thinks it worth proceeding further by then consulting with veterinarians who deal with these types of breathing problems (Pharyngeal). There are numerous veterinarians who deal with problems of the larynx but it would seem significantly fewer who deal with problems of the pharynx.


WHAT HAPPENS AFTER THE PROBLEM IS DIAGNOSED?


Firstly to proceed , in the majority of pharyngeal dysfunction cases , one has to accept that the condition diagnosed is the ‘most probable’ cause of the horses poor performance. Absolute diagnoses are uncommon as no matter what has been heard or seen during the diagnostic workup, a degree of extrapolation to actual race conditions is required. Unfortunately at this stage we can’t be in the horses airway during a race.

A report may well read  “following our investigations we feel that this ( Pharyngeal dysfunction) is the most likely cause of your horses loss of or reduced performance”  Treatment will then be comprised of either ‘(i) surgery   and / or

                                                                         (ii) management strategies’.


SURGERY -

There are numerous surgical procedures and results tend to vary in relation to the individual surgeons experience. Results quoted for specific procedures are very often those from the text book and may be misleading. Best to ask for your surgeons personal results. 

Surgery is not a ‘FIX’ but it should be a more permanent way to manage breathing problems. Surgery should deliver a more relaxed healthy and thence trainable athlete. The effects should be evident for up to 5 to 6 years of competitive racing. Even with cases where the post surgery race results aren’t very profitable there is often an overall saving in terms of eliminating excuses and thence having a quicker turnover. Training is not inexpensive. In these cases surgery is usually a benefit to the horse in other fields such as eventing, show jumping and dressage.( more saleable to other disciplines).

When to perform surgery and which horses for surgery?

The earlier surgery is performed the less likely permanent lung changes from infections and bleeding will limit future performance. Best to have some idea on innate ability so have your horse assessed by an experienced rider. So younger lightly or unraced horses with more innate ability are quite obviously more likely to give profitable returns. Horses with questionable ability may be better having management treatments until one has a clearer idea of ability. Don’t take too long though as training and cost are high often leaving me and other surgeons wondering why the then ‘cheaper’ surgical option wasn’t taken earlier! 


MANAGEMENT - Physical &/ or medical -

for the temporary treatment of pharyngeal dysfunction.

1) gear - tongue ties , nose bands, tongue bits, figure 8 bits, bit lifters

2) medical - antibiotics and anti-inflammatory drugs are often used to treat the lung disease that is initiated by the contamination of lungs with oral ( mouth) material. Nebulised drugs are used to manage the bronchospasm ( asthmatic type symptoms).


These are fine for short term symptomatic treatment.. but the cost of longer term or repeated treatments should be weighed against the surgical option. Correct breathing ( nasal) has been shown to significantly reduce the incidence of  episodes of lung disease and bleeding.

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Questions - (i) If my horse exhibits some of the above symptoms does it necessarily have a breathing problem?

Ans. -  No! ...... but it would be regrettable to not at least consider the possibility. i.e. investigate further ! you provide the history and get your veterinarian to do the rest.


                -  (ii) And where does all this information come from?

Ans. -   Quite simply from treating thousands of horses in numerous countries over many years and observing any changes ( long term physical, physiological and behavioural ) after surgery.


                -  (iii) Will my horse that is bred to get 2000m but currently only gets 1200m be able to go further after surgery?

Ans. -   The ability to ‘stay’ has as much to do with a horses willingness to relax in its races as it has to do with breeding. A competent breathing horse will relax! You work it out from there.


                   (iv) Could I have surgery done and medicate / nebulise the horse as well. Hedge my bets?

Ans. -    You could but experience has shown that longer term results may decline if you do. Do one or the other.


Happy racing.