44 Epizootic Laiyugo-traclieitis of Horses. 



Etiology. In its epizootical and clinical respects the disease is 

 very similar to eciuine influenza and cannot be separated from it com- 

 pletely the more so since the etiology of equine influenza is not yet 

 cleared up. The possibility, however, of the occurrence of contagious 

 catarrh independently of eciuine influenza cannot be denied, considering 

 the fact that cattle likewise suffer from an epizootic catarrh of the 

 respiratory passages and horses may suffer from epizootic laryngo- 

 tracheitis, even after having previously had an attack of influenza. 

 On the other hand, this is no conclusive proof since one attack of 

 influenza confers immunity only for a short time. 



The disease is usually observed annually. The extent of its 

 prevalence, however, varies considerably in different years. Its very 

 contagious nature is responsible for a frequently rapid extension within 

 a few days among the horses of the same stable so that it assumes an 

 enzootic and not uncommonly an epizootic character. The introduction 

 of the disease occurs vrith newly acfjuired horses, with remounts, etc. 

 The contagion may also be conveyed by persons or by the air. Younger 

 horses are most susceptible. In some epidemics, however, horses are 

 affected without reference to age. The period of incubation is 1 to 5 

 days according to past experiences. 



Symptoms. The most prominent symptom, which is never absent, 

 is a dry, short, strong, rough cough. If it is painful at all it is only 

 moderately so. The cough occurs either very frequently or on 

 the contrary after longer intervals. A marked tenderness of the 

 larynx and of the trachea can be demonstrated. A serous, later on 

 mucous, but usually scanty nasal discharge comes on which subsequently 

 often becomes more abundant and lumpy. If this is the case the lymph 

 glands of the laryngeal entrance swell moderately and mucous rales 

 are heard over the trachea. In some cases bronchitic symptoms become 

 manifest. The conjunctivae often appear normal or if there is an 

 elevation of temperature they are markedly reddened, often diffusely 

 rose red or yellowish-red or even dark red ; sometimes, on the contrary, 

 pale ; according to Meyer edema is seen in the lower portions of the 

 legs, the abdomen and the sheath of the penis. 



Fever is often present. The temperature usually does not rise 

 above IVJ° C, but it may not uncommonly go up to 41°. Even if 

 occasionally fever is not present at rest, more intense exercise will 

 elevate the temperature and at the same time accelerate the respiration 

 and the pulse beat. Many patients show lassitude and malaise which 

 contrasts with a comparatively insignificant psychic depression. 



Concerning weakness or paralysis of the hind extremities (hmibar cord disease) 

 following catarrh of the upper respiratory passages as observed by Kull and 

 Duvinage, see enzootic paralysis of the cord. 



The course of the disease is generally benign ; the disturbances 

 disappear in 8 to 10 days and after 8 or 10 days more the animals 

 are able to work again. In some epidemics and in foals under two 

 years old the period of convalescence lasts several, up to 6 to 8 weeks. 

 Sometimes pneumonia or pleuritis comes on as a complication, especially 

 if the animals have been worked hard during the disease. One attack 

 of the disease does not appear to insure any lasting immunity. 



The treatment consists more properly in feeding mashes, beets or 

 a dust-free dry feed, sojourn in the open air during the favorable 



