329 



tliG conditions whicli cause actual dislocation, and ;^ etit may often occur 

 in animals which have not been exposed to the ordinary causes, but 

 which have remained at rest in their stables. Sometimes these cases 

 are referred to falls in a slippery stall, or perhaps slipping when en- 

 deavoring to rise; sometimes to weakness in convalescing patients; 

 sometimes to lack of tonicity of structure and genertil debility; some- 

 times to relaxation of tissues from want of exercise or use. 



The reduction of these displacements of the patella is not usually at- 

 tended with difficulty. A sudden jerk or spasmodic action will often 

 be all that is required to spring the patella into place, when the flexion 

 of the leg at the hock ends the trouble for the time. But this is not 

 always sufficient, and a true reduction may still be indicated. To effect 

 this the leg must be drawn well forward by a rope attached to the lower 

 end, and the patella, grasped with the hand, forcibly pushed forwards 

 and inwards and made to slip over the outside border of the trochlea 

 of the femur. The bone suddenly slips into position, the excessive rigor 

 of the leg ceases with a spasmodic jerk, and the animal may walk or 

 trot away without suspicion of lameness. But though this may end 

 the trouble for the time, and the restoration seem to bo perfect and per- 

 manent, a repetition of the entire transaction may subsequently take 

 place, and perhaps from the loss of some portion of tensile power which 

 would naturally follow the original attack in the muscles involved, the 

 lesion might become a habitual weakness. 



Warm fomentations and douches with cold water will often j)romote 

 permanent recovery, and liberty in a box stall or in the field will in 

 many cases insure constant relief. The use of a high-heeled shoe is 

 recommended by European veterinarians. The use of stimulating lini- 

 ments, with frictions, charges or even severe blisters, may be resorted 

 to in order to prevent the repetition of the difficulty by strengthening 

 and toning up the i)arts. 



DISEASES OF MUSCLES AND TENDONS. 



Sprains. — This term expresses a more or less complete laceration or 

 yielding of the fibers of the muscles, tendons, or the sheaths surround- 

 ing and supporting them. The usual cause of a sprain is external vio- 

 lence, such as a fall or a powerful exertion of strength, with following 

 symptoms of soreness, heat, swelling, and a suspeusion of function. 

 Their termination varies from simple resolution to suppuration, and 

 commonly plastic exudation difficult to remove, i^oue of the muscles 

 or tendons of the body are exempt from liability to this lesion, though 

 naturally from their uses and the exposure of their situation the ex- 

 tremities are more liable than other regions to become their seat. The 

 nature of the prognosis will be determined by a consideration of the seat 

 of the injury a;nd the complications likely to arise. The treatment will 

 resolve itself into the routine of local applications, including warm 

 fomentations, stimulating liniments, counter irritation by blistering, 



