2G4 DISEASES OF THE HOESE'S FOOT 



decumbent. Strange to say, though, in man}' cases of 

 laminitis the animal persists in maintaining a standing 

 posture. Once down, however, one has sometimes the 

 greatest difficulty in persuading him again to rise. The 

 lying position is so long maintained that bedsores begin to 

 make their appearance, and the animal rapidly loses flesh, 

 not only by reason of the fever and the pain, but by giving 

 to rest the time he should normally give to feeding. 



Difficulty in rising is greatest when all four feet are 

 affected ; is nearly as great when the hind-limbs only are 

 in trouble, but is least when the disease exists alone in the 

 two fore-feet. 



The Coukse of the Disease and its Pathological 

 Anatomy. — As with most inflammations of any severity, so 

 with this we may consider the pathological changes taking 

 place in the foot under three headings : (a) The period of 

 Congestion ; {h) the period of Exudation ; (c) the period of 

 Suppuration. 



(a) Congestion. — In the early stages of laminitis there is 

 a state of engorgement of the vessels of the keratogenous 

 apparatus generally, but more particularly the laminal 

 portion of it. With the hoof removed at this stage the 

 sensitive laminae are found to be swollen, dark red in 

 colour, and affording a distinct feeling of increased thick- 

 ness when pressed between the fingers. Incised, there 

 escapes from the cut surface a large flow of dark venous- 

 looking blood. At this stage haemorrhages of the laminal 

 vessels occur. The escaping blood infiltrates the surround- 

 ing connective tissue, and in many cases destroys the 

 union between the horny and sensitive laminae. This 

 change is most noticeable in the region of the toe and the 

 commencement of the quarters, the os pedis appearing as 

 though pushed backwards by the escaping fluid collected 

 between the wall and the bone. In severe cases, fortunately 

 but rarely seen, the blood so escaping continues to infil- 

 trate, and separate the tissues until it is seen to be freely 

 oozing at the region of the coronet. (See reported case, 

 No. 1, p. 279.) 



