216 CLINICAL DIAGNOSTICS. 



conditions of the upper air passages as well as stenoses of the 

 nasal cavities since these conditions will also produce audible 

 breathing. Contractions or other deformities of the nasal 

 cavities can frequently be recognized upon superficial exami- 

 nation, or by the wheezing noise they produce. If the trouble 

 is unilateral, the peculiar noise will cease upon closing the af- 

 fected side, or become more pronounced upon obstruction of 

 the healthy nostril. 



If existing lameness or the presence of acute affections of 

 the respiratory apparatus or other organs make this method 

 of examination impossible, the laryngoscope may do valuable 

 service. (See p. 101.) 



IV, Examination for Epilepsy and Vertigo. 



Epilepsy is a chronic cerebral disease that is char- 

 acterized by paroxysms occurring at intervals and attended 

 with interruption or loss of consciousness and sensibility. 

 Vertigo (dizziness) is a similar affection; it is an inde- 

 pendent disease occurring in the form of periodical attacks, 

 disturbed equilibrium and consciousness. The difference be- 

 tween epilepsy and vertigo is that spasms are absent in the 

 latter. 



The diagnosis of these two diseases is not diffi- 

 cult if one has an opportunity to observe an attack. In the 

 intervals horses act perfectly normal. 

 Sometimes certain known conditions bring about an attack; 

 when making an examination of suspected animals we can 

 often make use of this knowledge to bring on an attack. 

 Horses may be hitched up and driven as on former occasions 

 when an attack was observed, etc. The fit of the harness 

 should be carefully inspected. Sometimes frightening or ex- 

 citing the animal, or driving with the face turned toward the 

 setting sun, or along streets sprinkled with alternating shade 

 of trees and the glaring light of the sun, \vill produce an at- 

 tack. If we cannot personally observe an 

 attack we must base our diagnosis upon 

 unobjectionable statements ofwitn esses. 



