PRINCIPLES OF VETERINARY SURGERY 637 



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this period of the disease is but slightly affected. The subjects may 

 grow fat, or at least retain the flesh remarkably well. In the small animal 

 before any other signs of general osseous lesions appear, they become per- 

 manently lame from visible lesions of the affected joints, or else break down 

 by the detachment of the tendons and ligaments of the parts most severely 

 diseased, or fracture the bones near or through the articulations. In many 

 cases, especially when the os pedis and os navicular are intensely involved, 

 the wrenching of the tendons and ligaments may be the very first evidence 

 that any disease has existed, with the exception, of the mysterious lamenesses 

 already mentioned. In the larger animals early after the appearance of the 

 lameness and the general symptoms of fatigue, the rami of the inferior 

 maxilla are found to be slightly tumefied along the alveolar margin. When 

 examined by palpation a wide, rounded, somewhat tuberous elevation is felt 

 running along the course of the bone just below the molar arcades, both 

 externally and within the mouth. At this stage the superior maxillary may 

 not be perceptibly involved, but as the disease progresses, it, too, will begin 

 to show a tuberous swelling in the concavity between its spine and the nasal 

 arch. Soon this concavity becomes over-full and gives to the patient the 

 physiognomy which gave birth to the American name "big-head." In' the 

 still more advanced stage the respirations become audible and the mastication 

 of food becomes first difficult, then impossible. The patient will also show a 

 tendency to remain recumbent for hours, and will often be unable to rise 

 without assistance. Horses cramped in a small, single stall in the recumbent 

 position for hours are especially liable to refuse to rise until given some as- 

 sistance, or else dragged out into a more favorable place to make the effort. 

 When this stage is reached they soon become emaciated, suffer from complica- 

 tions, and are finally destroyed to relieve a hopeless condition. 



The limb localization usually proves fatal or hopeless much earlier in 

 the course of the process, on account of the greater strain to which the 

 affected structures are subjected. If the bones of the head were subjected 

 to the same strain as the bones and tendons of the legs, they, too, would 

 prove the undoing of the patient much sooner. Their inactive function pro- 

 tects them against dissolution, and permits the process of rarefaction to 

 continue until mastication or respiration or both, are so markedly impaired 

 as to bring about the complications which cause death. Osteoporosis, itself 

 is not a fatal disease in any of its phases until some part of the skeleton 

 breaks down and renders necessary the slaughter of the patient to prevent a 

 Imgering death from complications. 



The cases of osteoporosis manifested in the better class of horses by the 

 detachment of ligaments and tendons, the fractures of bones, or the compound 

 dislocation of one or more articulations, are too numerous to mention. 

 These patients usually leave the stable in very good spirits, usually after a 

 period of rest made necessary for the treatment of lameness. They travel 

 a mile, two miles or even a much greater distance, suddenly fall severely 

 lame in one foot, perspire quite freely from distress, and finally refuse to be 

 urged farther. Often before the driver leaves his seat to investigate the 

 cause, the patient is walking on the posterior surface of the fetlock, com- 

 pletely broken down. Very frequently, before the animal is unhitched from 

 the vehicle one or even two or more legs, may become similarly afflicted. 

 In one case coming to our notice the coachman while unharnessing his 

 horse to lead him to a convenient stable in the neighborhood, found him 



