142 Veterinary Medicine. 



CROUPOUS IvARYNGlTiS IN SOLIPEDS. 



This is a rare affection in the horse, which has less disposition 

 to the production of false membranes than the other domestic 

 animals. As in other genera, the predisposition is greatest in 

 the young, and hence cases have been mostly seen in foals and 

 young horses. 



Causes. The occasion of the attack has in many cases been the 

 partial loss of vitality and resistance of the mucosa of the larynx 

 owing to contact with violent irritants. Riss records two cases, and 

 , Bouley one, determined by inhaling the hot gases and smoke in a 

 burning stable. Irritant gases like ammonia have long been 

 tlamed for such cases, as has the inhalation of pure chlorine 

 gas. Bretonneau, experimenting with caustic substances in- 

 jected into the trachea and bronchia (silver nitrate, mercuric 

 chloride solution, cantharidine), and succeeded in producing false 

 membranes. It seems, however, that an extreme measure of dis- 

 organization of the mucosa is necessary, to lay it open to the 

 microbian attacks which result in croupous products. Cadeac 

 claims cases from the forced administration of very hot drenches. 



To a less extent than in other animals, yet no less really, de- 

 bilitating conditions predispose, such as sudden, extreme changes 

 of temperature, exposure in the open field in cold, wet nights 

 when unaccustomed to this treatment, and even the drinking of 

 extremely cold water. 



As in other animals, the microorganisms, formerly enjoying a 

 saprophytic life in the air passages, attack the debilitated mu- 

 cous membrane and become active pathogenic factors. 



Symptoms. Dullness, leaving of food, hurried breathing, di- 

 lated nostrils, small, dry, painful cough, soon becoming resonant, 

 strong and croupy, highly injected mucosae, and very elevated 

 temperature are marked symptoms. The larynx is very tender 

 to touch, and the hand feels a distinct thrill or fremitus, from 

 the vibration of the false membranes. The breathing becomes 

 stertorous {roaring'), tremors pervade the whole body at inter- 

 vals, the face is drawn and anxious and the mouth may remain 

 open with the hanging tongue blue or violet. Auscultations of 

 the larynx will now detect a very coarse mucous r^le or gurgling 

 which is very characteristic. The nasal mucosa is of a deep red. 



