LAMINITIS. 1079 



in position. The latter usually becomes soaked with blood in a 

 very short time, but this is of no importance, as the blood remains 

 aseptic. A leather shoe or straw sandal is used to keep the parts 

 clear of the ground. 



Provided no great pain is shown and the dressing does not emit 

 any unpleasant odour or discharge, it may be left in position as long 

 as ten or twelve days. Increasing pain or offensive discharge 

 necessitate a change. ' As, however, the second dressing can seldom 

 be as complete or as accurately adjusted as the first, the change 

 should only be made for good reason. This operation has given 

 good results, and is worthy of trial in cases which prove intractable 

 to injections or other treatment. 



VI.— LAMINITIS. INFLAMMATION OF THE SENSITIVE LAMINAE. 



The term laminitis is applied to a spontaneous, generalised aseptic 

 inflammation of the keratogenous membrane, with more or less ostitis 

 of the os pedis. The lesions are always best marked in the anterior 

 portions of the foot, where the inflammatory process is most intense ; 

 this localisation is probably due to the situation and disposition 

 of the vessels of the plantar circle. Laminitis may be acute, sub- 

 acute, or chronic. It usually affects the fore-feet, sometimes the 

 hind-feet as well, but seldom these alone. In cattle the hind-feet 

 are more frequently affected than the fore -feet. 



The acute disease starts as a severe hyperemia of the kerato- 

 genous membrane and os pedis, the sensitive laminae being thickened 

 and infiltrated and their adhesion to the horny laminae weakened. 

 Exudation soon follows, and, if the process is not arrested, its immediate 

 effect is to loosen the connection between the hoof and its matrix, 

 and as separation is favoured by the weight of the body, especially 

 at the surface of the sensitive laminae, the most extensive of the 

 pathological changes occur at this point. 



Within twenty-four hours after onset of the disease, the parts 

 are much reddened and swollen, and proliferation of the young 

 epithelium is taking place on the surface of the sensitive laminae, 

 which are covered especially in the region of the toe with a very slightly 

 adherent, yellow fibrinous layer. Siedamgrotzky was perhaps the 

 first to point out that the pressure of the body-weight, and the pull 

 of the flexor pedis perforans tendon, tend to rotate the os pedis 

 around its transverse axis, and so to cause the toe to sink and the 

 wings to rise. A space more or less large is formed between the 

 displaced os pedis and the horny wall, and in the chronic condition. 



