8 Oct., 1907.] 



Diseases of Farm Animals. 



639 



surface of the shoe all round and allowed to set while the foot was being 

 held up. This remained /;/ situ three days before being removed, the 

 horse standing on tan bedding meanwhile. The decrease of the excessive 

 vascularity of the exposed parts was satisfactory, and the pressure treat- 

 ment was continued for two weeks — a half-and-half mixture of Portland 

 cement and plaster-uf- Paris being substituted on account of the brittle- 

 ness of the latter when used alone. The casts were removed everv three 

 days and the soles dressed with an astringent and antiseptic powder (car- 

 bolic crystals, zinc oxide, and calomel), and at each removal a gradual 

 cessation of the fluid secretion and cheesy fungoid growths was evidenced. 

 The soles and frogs dried up rapidly, and during the second week became 

 covered with a dry layer of horny matter which seemed to be healthy and 

 impervious to the slight discharge now issuing from the frog clefts. The 

 astringent and antiseptic dressings were continued, and within a month 

 the horse was put to work, and continued uuite sound, and without new 

 development of either thrush or canker. 



Sand Crack. 



By the term "Sand Crack" is meant a crack or fissure in the wall of 

 the hoof, running verticallv down from the coronet in the same 

 direction as the horn tubes, and extending through to the laminae and 

 sensitive structures. They usually occur on the inside quarters of the 

 fore feet and at the centre of the toe in the hind feet. Horses with 

 brittle or shelly "hoofs" are much disposed to sand cracks, and in that 

 sense heredity is a j;ronounced predisposing cause, such hoofs if shod un- 

 evenly, so that the pressure of body-weight is not equally distributed on 

 all parts of the wall, sole, and frog, will readily crack during fast trot- 

 ting 00 hard roads. Occasionally a sand crack is the result of a tread 

 or injury at the coronet, whereby the proper formation of wall horn is in- 

 terfered with. Horse-coper's tricks include the filling of sand crack with 

 wax," putty, or other stopping, and showing the horse with mud-caked 

 hoofs. 



Treatment. — If lameness is pronounced, poultices of bran or cold 

 water bandages should l>e resorted to for a day o<r two. and the crack 

 should be carefully freed of all dirt and foreign matter, and made clean. 

 The objects in (^native treatment are to arrest all movement of the edges 

 of the crack, and to promote a quick growth of solid (unsplit) horn from 

 the coronet. For the latter purpose the application of small quantities of 

 fly-blister at weekly intervals, or stimulating the coronet bv touching it oc- 

 casionallv cross\va\ s with a firing iron are most likelv to give advantageous 

 results. 



.Sand crack instruments. A, searini^ iron; ]i, metal clip. 



To arrest movement of the edges of the crack \arious devices are 

 adopted. An excellent method is what is known as "clasping" or "clip- 

 ping" the crack. This mav be done with the aid of special instruments 



