DISEASES OF THE HOESE. 421 



True, the majority of these last-described cases prove to be the lam- 

 initis in fact, yet the congestion may pass awa}^ and the extravasated 

 blood be absorbed without inflammation sufficient to warrant calling it 

 laminitis. The seat of greatest congestion will always be found in 

 the neighborhood of the toe, because of the increased vascularity of 

 that part, and, although at times it is limited to the podophyllons 

 tissue alone, any or all parts of the keratogenous membrane may be 

 affected by the congestion and followed finally by inflammation. 



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 twent3'-four or forty-eight hours develops 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 through- 

 out the lamina. 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 lame- 

 ness improves, the other symptoms graduallj^ subside, and eventually 

 health is regained. It is in these cases that a strong tendency to dis- 

 organization of a destructive character exists, hence it is we see so 

 many recover imperf ectl}" with marked structural changes permanently 

 remaining. 



Siibacute. — Subacute laminitis is most often seen as a termination of 

 the acute form, although it may exist independent of or precede an 

 acute attack. It is characterized by the mildness of its symptoms, 

 slow course, and modertite tissue changes. It may be present a long 

 time before an}^ 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 designate 

 any of the sequel83 of the acute and subacute forms of this disease. 

 Pure chronic inflammation of the laminae is not very commonly met 

 with but is most frequent in horses that have long done fast track work. 

 They have "fever in the feet" at all times and are continually sore; 

 both conditions being aggravated by work. Like chronic inflamma- 

 tion of other parts, there is a strong tendency to the development of 

 new connective tissue, which, by its pressure upon the blood vessels, 

 interferes with nutrition. Wasting of the coffinbone and inflamma- 

 tion of its covering with caries is not unusual. The continued fever 

 and impaired function of secretion resvilt in the production of a horn 

 deficient in elasticitj^, somewhat spongy in character, and inclined to 

 crumble. In some cases of "soreness" in horses used to hard or fast 

 work, there is evident weakness of the coats of the vessels brought on 



