200 



JUDGING FARM ANIMALS 



respiration becomes very difficult. The horse inhales na- 

 turally but has difficulty in exhaling. ' ' This, ' ? writes Had- 

 ley, 2 "requires the patient to make a special effort to force 

 out the air. As a result, there occurs a 'double pumping 

 action' of the flanks with two expulsive efforts instead of 

 one. This produces the so-called ' heave-line ' seen along the 

 flanks of affected horses. Disguised cases can be detected, 

 or tests can be carried out by feeding all the dusty hay the 

 horse will eat, then giving plenty of water and driving him 

 briskly." 



Roaring is a disease in which the horse breathes noisily. 

 The larynx is affected, but not the lungs. This is a paralysis 

 of the nerves and muscles of the parts, which results in a 

 whistle-like noise or roar when inhal- 

 ing. Roaring is manifested during ex- 

 ertion, yet a horse may be a roarer and 

 be driven some distance without becom- 

 ing especially noisy. The disease is he- 

 reditary, and animals suffering from it 

 should be disqualified for breeding pur- 

 poses. This malady may be cured in 

 a large per cent of cases by surgical 

 operation. 



Bone spavin, often referred to as 

 spavin, is found on the inner side and 

 front of the hock joint. The spavin 

 usually occurs on the lower part of the 

 joint, and when especially low down it 

 is known as a "low or jack spavin." 

 The joint surfaces may also become 

 enlarged, forming a "blind spavin," 

 showing no enlargement, but accom- 

 panied by severe lameness. Spavin is 

 caused by a strain or injury and con- 

 sists of accumulations of bony matter 

 at the joint. This is usually shown 



8 The Horse in Health and Disease. F. B. Hadley, Philadelphia, 1915. 



Fig. 111.' 'Bone 

 spavin is found on the 

 inner side and front of 

 the hock joint." (Photo 

 by courtesy College 

 Veterinary Medicine, 

 Ohio State University. ) 



