DISEASES OF HORSES 289 



be found, a condition more apt to obtain where the animal is made to 

 continue work after a development of symptoms has begun. 



Acute. In the acute form of laminitis the symptoms may all 

 develop rapidly, or it may commence by the appearance of a little 

 soreness of the feet which in twenty-four or forty-eight hours devel- 

 ops into a well-marked case. This peculiarity of development is due 

 to one of two causes. Either the congestion is general, but takes 

 place slowly, or else it begins in one or more points and gradually 

 spreads throughout the laminae. These acute cases generally run 

 their course in from one ,to two weeks. Usually a culmination of the 

 symptoms is reached, if the patient is properly treated, in from three 

 to five days ; then evidences of recovery are discernible in favorable 

 cases. The lameness improves, the other symptoms gradually sub- 

 side, and eventually health is regained. It is in these cases that a 

 strong tendency to disorganization of a destructive character exists, 

 hence it is we see so many recover imperfectly with marked struc- 

 tural changes permanently remaining. 



Subacute. Subacute laminitis is most often seen as a termina- 

 tion of the acute form, although it may exist independent of or pre- 

 cede an acute attack. It is characterized by the mildness of its symp- 

 toms, slow course, and moderate tissue changes. It may be present a 

 long time before any pathological lesions result other than those 

 found in the acute form, and when these changes do take place they 

 should rather be viewed as complications. 



Chronic. Chronic laminitis is a term used by many to desig- 

 nate any of the sequelae of the acute and subacute forms of this 

 disease. 



Complications. Complications concurrent with or supervening 

 upon laminitis are frequent and varied, and are often dependent 

 upon causes not fully understood. Excessive purgation is one of 

 the simplest of these, and not usually attended with dangerous con- 

 sequences. It rarely occurs unless induced by a purgative, and the 

 excessive action of the medicine is probably to be explained upon the 

 theory that the mucous membrane sympathizes with the diseased 

 laminae, is irritable, and readily becomes overexcited. The discharges 

 are thin and watery, sometimes offensively odorous, and occasionally 

 persist in spite of treatment. It may prove disastrous to the welfare 

 of the patient by the rapid exhaustion which it causes, preventing 

 resolution of the laminitis, and may even cause death. 



Sidebones. A rapid development of sidebpnes is one of the 

 complications, or, perhaps better, a sequel of laminitis not often met 

 with in practice. Here the inflammatory process extends to the lat- 

 eral cartilages, with a strong tendency to calcification. The deposi- 

 tion of the lime salts is sometimes most rapid, so that the "bones" 

 are developed in a few weeks ; in other instances they are deposited 

 slowly and their growth is not noted until long after the subsidence 

 of the laminitis, so that the exciting cause is not suspected. 



Suppuration of the sensitive membrane is a somewhat common 

 complication, and even when present in its most limited form is 

 always a serious matter; but when it becomes extensive, and espe- 



