264 DISEASES OF BONE. 



bone surrounding them, and when they reach a sufficient size, they can be 

 seen to contain a small quantity of pink granulation tissue surrounding the 

 vessel. If a portion of the bone at this stage be macerated, it presents a 

 Ijorous, spongy appearance, almost resembling cancellous tissue. The 

 Haversian canals are the extremely minute canals (they vary from a 200th 

 to 2,5O0th part of an inch in diameter) which run through the substance of 

 bone ; and cancellous tissue is the spongy portion of bone. 



Considering that osteoporosis is apparently confined to certain districts, 

 and that in other places errors of diet, no matter how much intensified, 

 appear to have no effect in setting up this disease, I cannot resist making 

 the conjecture that it is due to some specific poison contained in the fodder 

 consumed. Up to the present, no exact information has been obtained 

 respecting the manner in which the diseased condition of bone is brought 

 about, 'ihe facts given in the preceding paragraphs of this section, show 

 that osteoporosis can occur when the food has a sufficiency of nutrient 

 matter, including salts of lime. 



DISTINGUISHING SIGNS.— See "Distinguishing Signs of Rickets," 

 page 267. 



PRINCIPLES OP TREATMENT.— The best results have been obtained 

 from the axloption of the principle that the disease is due to some noxious 

 matter in the forage ; complete change of grass or hay is accordingly 

 advisable. I have in no case been able to trace the disease to the con- 

 sumption of any particular kind of corn. Knowing the good effects of the 

 administration of salts of lime, iron, phosphorus (page 267), and fat (in the 

 form of cod liver oil, linseed oil or butter, for instance) in apparently allied 

 diseases of bone, these agents might he employed here. 



TREATMENT. — Well-developed cases are stated to have been 

 cured solely by change to a dry location. Change the grass or 

 hay. Give if possible (as is the custom in Australia and South 

 Africa) unthrashed young oats (oaten hay). If sound hay or grass 

 different to that on which the affected animal was fed, be unobtain- 

 able, substitute for it, bran and straw, say, seven pounds of the 

 former (to be given dry) and a full supply of the latter. Bran is 

 recommended, because it is very digestible, and contains a large 

 amount of bone-forming material. 



In 1879, several slight ca^es, which were at once brought out of 

 the coal pits, recovered. They were put in loose boxes at the 

 farm, and treated with a mild .laxative (linseed oil), followed by 

 mineral tonics and chlorate of- potass dissolved in the drinking 

 water. Mashes and grass were given as food. A pint of linseed 

 oil would be sufficient as a laxative ; and a drachm of sulphate of 

 iron might be given daily in the food, and 1 oz. of chlorate of 

 potass in the water. Salt should be supplied, either iu the form 

 of a large lump of rock salt, for the animal to lick when he likes ; 

 or mixed in the food, to an amount of 3 or 4 oz. daily. We might 

 treat as for rickets (see following section). 



