Proceedings of a Workshop on - The Havemeyer Foundation
Proceedings of a Workshop on - The Havemeyer Foundation
Proceedings of a Workshop on - The Havemeyer Foundation
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<strong>Havemeyer</strong> Foundati<strong>on</strong> M<strong>on</strong>ograph Series No. 11<br />
SALES: PROBLEMS IN DIAGNOSIS OF RLN –<br />
UK PERSPECTIVE<br />
D. R. Ellis, T. R. C. Greet † and J. G. Lane *<br />
Greenwood, Ellis & Partners, Reynolds House, 166 High Street, Newmarket, Suffolk, † Rossdale & Partners,<br />
Beaufort Cottage Equine Hospital, Cott<strong>on</strong> End Road, Exning, Newmarket, Suffolk CB8 7NN and * Department<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> Clinical Veterinary Science, University <str<strong>on</strong>g>of</str<strong>on</strong>g> Bristol, Langford House, Langford, Bristol, BS40 5DU, UK<br />
Tattersalls, Ltd C<strong>on</strong>diti<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> Sale re Wind<br />
C<strong>on</strong>diti<strong>on</strong>s in Thoroughbred Yearlings or Horses<br />
in Training:<br />
1978–1983 A horse is returnable if it can be<br />
heard to make a characteristic<br />
abnormal inspiratory sound when<br />
exercised actively.<br />
1984 As above but add and/or has<br />
laryngeal hemiplegia when<br />
examined with the endoscope.<br />
1985 Makes a characteristic abnormal<br />
inspiratory sound AND has laryngeal<br />
hemiplegia (RLN).<br />
After the horse is sold the purchaser appoints a<br />
veterinary surge<strong>on</strong> to listen when the horse is<br />
lunged and if it makes any abnormal inspiratory<br />
noise it is endoscoped. If it is found to have<br />
recurrent laryngeal neuropathy (RLN) the<br />
purchaser returns the horse to Tattersalls for<br />
adjudicati<strong>on</strong> by their panel. <strong>The</strong> panel has<br />
included the authors since 1984 with occasi<strong>on</strong>al<br />
alternates. Yearlings are returnable within 24 h <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
sale, and horses in training within 7 days. <strong>The</strong><br />
panel examines the horse so<strong>on</strong> after its return,<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g>ten later <strong>on</strong> the same day as the original test by<br />
the purchaser’s veterinary surge<strong>on</strong>. Each member<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> the panel palpates the larynx for atrophy,<br />
cartilage symmetry and surgical scars. <strong>The</strong> larynx<br />
is also palpated immediately after exercise for<br />
fremitus and the right arytenoid depressi<strong>on</strong> test.<br />
<strong>The</strong>se observati<strong>on</strong>s provide supportive evidence<br />
and with the excepti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> surgical scars would not<br />
be decisive. <strong>The</strong> yearling is then lunged <strong>on</strong> both<br />
reins at the canter which may be repeated <strong>on</strong> a<br />
particular rein but it is never lunged to exhausti<strong>on</strong><br />
and the exercise lasts <strong>on</strong>ly a few minutes. <strong>The</strong><br />
lunging ring is well designed with good acoustics<br />
and a fibresand surface. Horses in training are<br />
ridden at a fast canter uphill <strong>on</strong> a polytrack surface<br />
with members <str<strong>on</strong>g>of</str<strong>on</strong>g> the panel standing close to the<br />
end <str<strong>on</strong>g>of</str<strong>on</strong>g> the canter to hear the animal pass by. This<br />
exercise can be repeated if necessary. <strong>The</strong> horse is<br />
then allowed to settle down after the exercise<br />
before it is endoscoped. Originally the panel<br />
endoscoped horses before exercise but this policy<br />
was changed in order to mimic the examinati<strong>on</strong> by<br />
the purchaser’s veterinary surge<strong>on</strong> and eliminate<br />
bias in the exercise test. <strong>The</strong> horse is scoped<br />
without a twitch, if possible, and <strong>on</strong>ly sedated if<br />
essential and with the agreement <str<strong>on</strong>g>of</str<strong>on</strong>g> the vendor and<br />
purchaser. <strong>The</strong> larynx and pharynx are examined<br />
via the right nostril in order to reduce the parallax<br />
effect for left sided RLN. During the examinati<strong>on</strong><br />
the nostrils are blocked and deglutiti<strong>on</strong> is<br />
stimulated. <strong>The</strong> panel does not employ a slap test.<br />
Until recently each member examined the larynx<br />
via the same endoscope in sequence. A videoendoscope<br />
is now used but the examinati<strong>on</strong> is not<br />
recorded <strong>on</strong> tape<br />
Endoscopic criteria for RLN which mean the<br />
horse will be returnable include gross resting<br />
asymmetry <str<strong>on</strong>g>of</str<strong>on</strong>g> the rima glottidis, failure to achieve<br />
symmetric or full abducti<strong>on</strong> and failure to<br />
maintain symmetric abducti<strong>on</strong> during a complete<br />
inspirati<strong>on</strong>, ie premature weakness. Each panelist<br />
forms his own view but sometimes members have<br />
discussed certain aspects such as the character <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the inspiratory noise or the endoscopic findings. In<br />
most cases the decisi<strong>on</strong> was unanimous but in 11.5<br />
% or 41 cases out <str<strong>on</strong>g>of</str<strong>on</strong>g> 356 between 1989 and 2002<br />
majority decisi<strong>on</strong>s were reached.<br />
Problems with the system include incomplete<br />
examinati<strong>on</strong> by a purchaser’s veterinary surge<strong>on</strong><br />
and some veterinarians have a higher percentage<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> passes am<strong>on</strong>g those they return to the panel.<br />
Judgement <str<strong>on</strong>g>of</str<strong>on</strong>g> noise can be difficult in yearlings<br />
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