Veterinary clinic

Breathing, stride andcould they be linked?

Mild respiratory problems have oftenbeen overlooked inshow jumpers,but recent research has shown thatbreathlessness could limit

)~ performance more than originallythought. Dr David Marlin PhD explains

FOR every stride ahorse takes incanter and gallop ittakes one breath.

Unlike in walk and trot,where inhalation andexhalation occurindependently ofthesteps, in the two fastestgaits breathing and strideare locked together inperfect synchrony.

It stands to reason,therefore, that if a horsehas trouble moving air inand out of its lungs it willhave an effect on stridepattern. So if your horse isstrugglingto catch hisbreath, is his performancebeing compromised and ifso what can we do about it?

The reason forthe linkbetween stride pattern andbreathing is to ensure thatthe horse does not use anymore energy than isnecessary. When a horsebreathes in, the diaphragmcontracts, which is aidedby the chest stretchinglonger as he starts to take astride, while breathing outis assisted by the forelegslanding on the ground andcompressing the front ofthe ribcage helping to forceair out (see diagram).

Being able to control thehorse's stride is perhaps

A showjumpinground-byseconds

75the approximateduration of a showjumping course

the time the horsespends in the air overevery fence

15the number of jumpingefforts

20the total amount of timeduring a round when thehorse is unable tobreathe

most crucial in showjumping, where coursesare designed on the basisof specific stride intervalsbetween jumps and theabilityto meeta fence onthe correct stride isparamount.lfthe horse

For a third of the jumping round,the horse is unableto breathe

does not maintain thecorrect length of stridewhen approaching a fence,he will either take off too faraway ortoo close, both ofwhich can result in areduction in powerfromthe muscles and cause thehorse to lose height.

Airways awarenessTOP-class show jumpersoften travel long distancesfor long periods and maybe stabled in dusty

competition stables, sothey may already be moresusceptible to persistent,undiagnosed low-graderespiratory disease. Itdoesn't matter whether weare talking about upper orlower airway problems asthey can both affect thecoupling of breathingand stride.

In the past, few ridersbothered to get thei r vet toexamine the airways oftheir show jumper in the

bel ief that breathi ng doesnot playa big part in theirperformance because therounds are so short.However, even during a75-second jumping round,about70% ofthe horse'senergy comes fromaerobic metabolismrequiring oxygen, which inturn necessitates a good,healthy respiratorysystem.

In addition tothephysical aspect of

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performance

breathing, thepsychological impact ofstruggling to draw breathhas also perhaps beenunderestimated. Thinkaboutyourown breathing:99% ofthe ti me we areunaware that we are doingit, but imagine you have abad cold or someone holdsa hand overyourmouth; allof a sudden we are veryaware of our respiratorymovements. It is the samefora horse.

When a horse is working,the amount of air moved inand out, referred to asventilation, is directlyrelated to how hard he isbeing pushed. Anythingthat interferes with airmovement will beimmediately sensed by thehorse. This can affect thehorse's concentration andifhe is distracted by asensation of even mildbreathlessness(dyspnoea) then hewon't

THE BREATHING EQUATIONG~~When the horse pushes off from the ground the" chest expands and the diaphragm contracts~\ As the horse leaves the ground it will have inhaledW for the final time before landing

•" While in mid-air the horse holds its breath.\,!lI The higher the jump the longer it will be before

the horse is able to exhale~D~~~As the horse's forelegs hit the ground on landing'"~,~ the front of the ribcage is compressed, which

helps force the air out

be listeningto the rider. Hemay try to put in moreeffort or he may slow down,or even, in some cases,may stop altogether.

No time to draw breathWE know that when ahorse jumps it holds itsbreath while it is intheair.However, when negotiatingcombinations with one ortwo strides in between, thehorse will not take anotherfull breath until it hascompleted thecombination.

So, ifthis is put in thecontext of a 75-secondround with approximately15 jumping efforts,assuming the horse is inthe air for one second witheach Jumping effort, thenfor a fifth ofthe jumpinground the horse is unableto breathe. The abilitytomove air in and outbetween jumps istherefore vital.

Unlike humans, thehorse can only breathethrough its nostrils and notthrough its mouth.Therefore any obstructionofthe nasal passages in

the horse can have aneffect on the abilitytomove air in and out.

Horses working harderhave to breathe harder andthe heavier the horsebreathes, the more itsnasal passages are suckedin. This means that thespace for airto movearound becomes narrower,which places greaterstress on the respiratorysystem. We might evenconsider this a design faultin the horse.

Finally, it should benoted that show jumpingplaces sufficient stress onthe membranes betweensmall airways and thesmall blood vessels in thelungs to make brokenblood vessels in the lungs(EIPH or "bleeding")common. While very fewJumpers will have blood atthe nostrils followingtraining or competition,recent work from a groupof vets in Belgium showedthat 38% of amateur and42% of international-levelhorses had broken bloodvessels in the lungs duringcompetition. H&H

Ways tooptimise-respiratoryefficacy~ MAKE sure that yougive your horseadequate time to warmup. During exercise thehorse relies on thecontraction of itsspleen to push morered blood cells intocirculation to carry t",more oxygen. Notwarming up your horsecan mean the spleenwon't release as manyred blood cells, thuslimiting the amount ofoxygen and causingearlier fatigue. If thewarm-up is too intense,this can result in thehorse using up largeamounts of glycogenand production of ahigh level of lactic acidmay result in fatigueduring the round.

~ CONSIDER gettingyour horse scoped byyour vet once or twiceevery season,particularlyin advance of anymajor competition orlong journey.

~ ENSURE that if yourhorse starts makingany abnormalrespiratory noise youget it investigated forupper airwayobstructions such asroaring (laryngealparalysis), which maybe compromisingperformance.

~ IF your horse has abreathing problem,consider using equinenasal strips if your vetagrees. These arescientifically proven toreduce the resistanceto air movementthrough the nasalpassages, which willmean the horse has toput less effort intobreathing and canconcentrate onjumping. Nasal stripshave also been provento reduce bleedingduring exercise.

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6horseandhound.co.uk

performance

breathing, thepsychological impactofstruggling to draw breathhas also perhaps beenunderestimated. Thinkabout your own breathing:99% ofthe ti me we areunaware that we are doingit, but imagine you have abad cold or someone holdsa hand overyourmouth: allof a sudden we are veryaware of our respiratorymovements. It is the samefora horse.

When a horse is working,the amount of air moved inand out, referred to asventilation, is directlyrelated to how hard he isbeing pushed. Anythingthat interferes with airmovement will beimmediately sensed by thehorse. This can affect thehorse's concentration andifhe is distracted by asensation of even mildbreathlessness(dyspnoea) then he won't

THE BREATHING EQUATIONla~"When the horse pushes off from the ground the\V chest expands and the diaphragm contracts~ As the horse leaves the ground it will have inhaledW for the final time before landing~ While in mid-air the horse holds its breath.V The higher the jump the longer it will be before

the horse is able to exhale"D~'As the horse's forelegs hit the ground on landing"""'] the front of the ribcage is compressed, which

helps force the air out

be listeningto the rider. Hemay try to put in moreeffort or he may slow down,or even, in some cases,may stop altogether.

No time to draw breathWE know that when ahorse jumps it holds itsbreath while it is intheair.However, when negotiatingcombinations with one ortwo strides in between, thehorse will nottake anotherfull breath until it hascompleted thecombination.

So, ifthis is put in thecontext of a 75-secondround with approximately15 jumping efforts,assuming the horse is inthe air for one second witheach Jumping effort, thenfor a fifth ofthe jumpinground the horse is unableto breathe. The abilitytomove air in and outbetween jumps istherefore vital.

Unlike humans, thehorse can only breathethrough its nostrils and notthrough its mouth.Therefore any obstructionofthe nasal passages in

the horse can have aneffect on the abilitytomove air in and out.

Horses working harderhave to breathe harder andthe heavier the horsebreathes, the more itsnasal passages are suckedin. This means that thespace for airto movearound becomes narrower,which places greaterstress on the respiratorysystem. We might evenconsider this a design faultin the horse.

Finally, it should benoted that show jumpingplaces sufficient stress onthe membranes betweensmall airways and thesmall blood vessels in thelungs to make brokenblood vessels in the lungs(EIPH or"bleeding")common. Whileveryfewjumpers will have blood atthe nostrils followingtraining or competition,recent work from a groupof vets in Belgium showedthat 38% of amateur and42% of international-levelhorses had broken bloodvessels in the lungs duringcompetition. H&H

Ways tooptimiserespiratoryefficacy>- MAKE sure that yougive your horseadequate time to warmup. During exercise thehorse relies on thecontraction of itsspleen to push morered blood cells intocirculation to carrymore oxygen. Notwarming up your horsecan mean the spleenwon't release as manyred blood cells, thuslimiting the amount ofoxygen and causingearlier fatigue. If thewarm-up is too intense,this can result in thehorse using up largeamounts of glycogenand production of ahigh level of lactic acidmay result in fatigueduring the round.

>- CONSIDER gettingyour horse scoped byyour vet once or twiceevery season,particularlyin advance of anymajor competition orlong journey.

>- ENSURE that if yourhorse starts makingany abnormalrespiratory noise youget it investigated forupper airwayobstructions such asroaring (laryngealparalysis), which maybe compromisingperformance.

>- IFyour horse has abreathing problem,consider using equinenasal strips if your vetagrees. These arescientifically proven toreduce the resistanceto air movementthrough the nasalpassages, which willmean the horse has toput less effort intobreathing and canconcentrate onjumping. Nasal stripshave also been provento reduce bleedingduring exercise.