296 DISEASES OF THE CELLULAR MEMBRANE. 



when congestion has taken place, it requires a greater effort 

 to propel the blood into the veins, against gravity, than to 

 discharge it in the form of aqueous effusion. The same 

 reasoning will account for the disposition there is in the hind 

 legs to fill. 



Turn the Horse out of the warm stable, and expose 

 him to the open air, in a short time, all swelling will leave 

 his legs. The cold air has operated as a bracer on his legs : 

 it has allayed febrile irritation; at the same time, it has in- 

 creased the power of the heart, and so removed all conges- 

 tion. The exercise which the animal now takes, also tends 

 to augment the secretions and excretions ; and thus to incite 

 the absorbents to greater action. 



Debility. — The circumstance of horses being attacked 

 with swelled legs during spring and autumn, the seasons 

 when they are shedding their coats, and of such horses being, 

 from their tender age, their softness, or laxity of fibre, 

 weaker than others, has induced veterinary writers to as- 

 cribe the disorder to debility. Specious as this doctrine 

 appears, I cannot consider debility to be concerned other- 

 wise than indirectly. Horses that are in a state of compa- 

 rative debility, possess a watery blood, with diminished 

 powers of circulation : I regard dropsy as the result of 

 vascular disturbance ; which, after all, must be the exciting, 

 debility being only the predisposing, cause. 



Degrees of intensity, present themselves in swelled legs, 

 ascending from the simple form, or "filled'' to the state 

 termed "round.'' A horse accustomed to daily exercise^ 

 will, from standing without any, "fill" in his hind legs : 

 those parts will become infiltrated, for want of the accus- 

 tomed locomotion. In this respect, however, horses exhibit 

 remarkable differences : some will stand for weeks, while 

 others will hardly stand twenty-four hours, without swelling. 

 As a general rule, horses in condition, possessing sinewy 

 legs, and in the middle period of life, are least prone to ex- 

 hibit oedema. 



Mere filling of the legs can hardly be said to amount to 

 disease. The case that calls for medical interference, is 



