When the bones are enlarged their softness and friability may be shown by pricking with a needle, which will often freely penetrate the rarefied bony tissue. It should be first rendered antiseptic by dipping in strong carbolic acid.
From the first the general health fails, there is difficulty in mastication, digestion is more or less impaired, nutrition is imperfect and muscular flabbiness, weakness and wasting advance more or less rapidly. In advanced cases emaciation is often a marked feature.
Examination of the urine gives valuable indications, though the results obtained have been supposed to be contradictory. While rarefaction of the bone is advancing rapidly the urine is charged with an excess of phosphates in ratio with the activity of the morbid process. When on the other hand the disease has come to a standstill and the process of repair in the rarefied bones has begun, the absence of phosphates is no less characteristic. A patient therefore may show greatly enlarged and softened bones with persistent lameness, and yet the urine may show little or no phosphate. The phosphaturia may, therefore, be made the basis of a reasonable prognosis. Excess of phosphates indicates an active pathological process, with an uncertain outcome, while the absence of phosphates indicates an arrest of rarefaction and holds out good hope of recovery.
I have long observed the same in cases of obstinate and intractable spavins, splints, ringbones and other bone diseases. Phosphaturia bespeaks a faulty nutrition of the bone and explains the failure of remedial measures, while lack of phosphates in the urine, or a reduction to the normal amount is likely to become a guarantee of improvement under local treatment. The treatment however, must be first constitutional to correct the condition of malnutrition and then local to correct the osteitis.
Prevention and treatment. As in rachitis hygienic measures give the most uniformly good results. The change of stable is especially demanded from a cellar or basement stable, one with joists laid on the ground or one with an earth floor saturated with urinary and feculent products. In different cases an enzootic has been arrested, coincidently with the removal of the stock to the floor above, and in others with the removal of the filth saturated earth beneath a ground floor, and the laying of a new floor with ample space beneath for the free circulation of air. In the same line would be thorough drainage of the site and to carry off liquid manure to a well ventilated receptacle. Exposure to cold and wet is to be sedulously avoided as greatly favoring the onset of the disease, and hurrying the milder cases into a fatal activity. Free air and sunshine are all important and it is the universal experience that city cases taken early and sent to dry, sunny pastures, mostly recover, or at least undergo marked amelioration. The fact that certain cases originate during an open air life does not invalidate this position but merely shows that other pathogenic conditions may be too potent to be overcome by this hygienic one.
A liberal allowance of sound grain is essential to success, even in the case of patients sent to pasture. Those that have recovered or improved at pasture, should be retained in the country and on no account returned to the same city stables in which they contracted the disease. Even in the country a different stable should be secured if possible.
Any food that has manifestly contributed to the disease, should be withheld (bran, millet, musty or fermented food or that drawn from particular fields).
Overwork must be forbidden, and indeed any work at all during the active stage of the disease. The victim should also be withdrawn from breeding, at least until it has fully recovered the normal consistency of its bone.
In cases aggravated by cold or wet, or which show the rheumatic propensity to shift from place to place, sodium salicylate in ounce doses several times a day may appear to benefit, and as a germicide this may be tried on all cases. Salicin, salol, or phenacetin may be used as substitutes. Where the disease has been largely localized, blisters have appeared to be beneficial.
Phosphates and phosphorus have been lauded by German veterinarians, but in other hands, and when the morbid process was active they have proved useless, or even hurtful. Bone dust or phosphate of lime or soda may be freely used at any time and appears to act as a general tonic, beside supplying lime and phosphoric acid which may possibly be availed of for bone nutrition. Phosphorus and phosphorated oil in excess always softens the bone and much more so when this process is already excessive. In small doses (gr. ⅙ to ½) and after the process of rarefaction has ceased, it is valuable in hastening bone consolidation and fitting the patient to return to work.