182 
DISEASES OF THE LARYNX AND TRACHEA. 
by performing oesophagotomy. The uncertainty of diagnosis during life generally 
prevents rational treatment. Lorenz saw a horse die from pleurisy, and found 
a carcinoma which had led to rupture of the oesophagus. Molni detected a 
tumour in the left oesophageal furrow in a cow, which, after each feeding time, 
showed tympanites. He regarded the case as one of goitre. 
YIIL—DISEASES OF THE LARYNX AND TRACHEA. 
(1.) INJURIES, INFLAMMATIONS, AND TUMOURS IN 
THE LARYNX. (LARYNGITIS. PERILARYNGITIS.) 
Only in carnivora is the larynx accessible to direct inspection. This is 
effected for clinical purposes by drawing out the tongue and depressing it 
with some blunt instrument (scissors). The laryngeal mirror used by 
Nawratil and Schmidt is of little value, and is seldom used on account of 
the animal’s resistance. Until recently, inspection of the larynx in the 
larger animals appeared impossible, but Polansky and Schindelka, with the 
assistance of the Vienna optician, Leiter, have constructed instruments for 
examining the larynx and pharynx of the horse, and amongst others the 
rhinodaryngoscope, which affords not only clear but extensive views of this 
region. Its construction is complicated, its use requires the electric light, and 
its application in veterinary practice has accordingly as yet been limited; but 
it is very serviceable for clinical observation and for teaching. 
On account of its protected position between the branches of the lower 
jaw, the larynx seldom suffers from injuries from without, though sharp 
foreign bodies swallowed with the food may pierce and inflame the 
mucous membrane. Rowland removed from the pharynx of a horse a 
fish-hook, which had penetrated the larynx. Injuries of the larynx 
occur oftener than is supposed, but not so frequently as those of the 
pharynx, and produce either acute or chronic inflammatory processes. 
The acute are clinically comprised under acute laryngitis, and are 
considered in the text-books on special pathology and therapeutics. 
The chronic lead to proliferation of connective* tissue in the neighbour¬ 
hood of the laryngeal cartilages (perilaryngitis chronica fibrosa) or pus 
and abscess formation. 
Kiihnert saw a case of perichondritis suppurativa laryngea in a pig. 
An abscess had formed in the submucous tissue of the right arytenoid 
cartilage, and markedly narrowing the glottis, caused dyspnoea; the 
animal was slaughtered. Leisering detected swelling of the vocal cords 
and of the mucous membrane of the laryngeal pouches in a dog which 
had suffered from severe cough; and Hutchinson makes a similar report 
of a pig, killed on account of dyspnoea. Necrosis of the cricoid cartilage 
had occurred. 
Perilaryngitis chronica fibrosa is commonest in horses. Progressive 
increase of connective tissue occurs, which sometimes undergoes ossifica¬ 
tion ; its retraction fixes the arytenoid cartilages, narrowing the glottis, 
and producing more or less severe dyspnoea. Gurlt reports this condition 
