CHAPTER III. 



ACUTE INFECTIOUS DISEASES LOCALIZED IN 

 CERTAIN ORGANS. 



STRANGLES. CORYZA CONTAGIOSA EQUORUM. 



Definition. — Strangles is an acute contagio-infectious dis- 

 ease of , horses, asses and mules, due to a specific streptococcus, 

 which leads to catarrh of the upper air passages and abscess 

 formation in lymph glands. 



Occurrence. — Strangles is a disease of colthood and is 

 therefore most prevalent in breeding districts. Adult or 

 aged horses are more rarely attacked. The disease is most 

 common in colts from six months to five years of age, although 

 cases in patients under two months are not rare. The dis- 

 ease is wide-spread, but Ireland and the Argentine Republic 

 are said to be free from it. Generally speaking, strangles is 

 a benign disease, but by checking the growth and sometimes 

 causing the death of colts, it attains economic significance. 

 Furthermore, some outbreaks are malignant in character 

 and lead either to considerable losses from death (internal 

 abscesses) or permanent injury through sequelae (roaring, 

 pharyngeal paralysis). 



Etiology. — The Streptococcus equi of Shutz, ( found in the 

 lymph glands and nasal discharge of affected animals. 



Natural Infection. — The streptococcus probably enters the 

 body through the intact nasal mucous membrane, although 

 other mucous surfaces (throat, bowel, vagina) may form ports 

 of entry. Nasal discharge and pus from lymph-gland ab- 

 scesses or more rarely skin lesions are taken in with the food 

 and water, reaching the upper air passages. 



In breeding establishments strangles is usually introduced 

 by a horse which has not yet fully recovered from the disease. 



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