DISEASES OF DOMESTIC ANIMALS. 81 



the articular cartilage to be destroyed, nature endeavours to repair 

 this by throwing out ossific matter, and the two bones become 

 united, until it is sometimes difficult to see any point of union. The 

 changes were similar, but to a greater extent. In some cases the 

 bone dies and irritates the surrounding tissues, which ends in sup- 

 puration, or a discharge of matter. The matter becomes somewhat 

 fetid and ichorous. It destroys the hair over which it flows and 

 smells of sulphureted hydrogen. If you press upon the matter from a 

 fistulous opening, you may find small hard particles, which are small 

 particles of bone which have become detached. The treatment is dif- 

 ferent in this case from spavin, ringbone, etc. Find and remove the 

 diseased part, scrape the bone with a small bone spoon, or in other 

 cases take a small portion of bone off with chisel. The action of cer- 

 tain acids will bring about a healthy action, as hydro-chloric or 

 sulphuric acid, but you must be careful in using them. If you cannot 

 excise the bone, the use of sulphuric acid and water — one part of acid 

 to one of water, or one to four, will bring about a healthy action. As 

 well as local, there is benefit from constitutional remedies, as good 

 food, tonics, etc. If in a debilitated condition, the healing process 

 will be assisted by giving a dose of iron. In ringbone, spavin, etc., 

 the treatment is different. We do not scrape the bone, but we arrest 

 the action by a generous diet and counter-irritation. It is difficult to 

 tell how these act, but they tend to produce inflammatory action and 

 hasten the process of exudation. If the articulations are destroyed, 

 then nothing can be done to cure or reduce the enlargement. When a 

 portion or whole of a bone dies, then it is called 



Necrosis, and it is analagous to gangrene in the soft tissues. By 

 this we understand death, or mortification of a bone, the result of 

 inflammation. It is not very common in our patients — that is, total 

 necrosis of any large bone. It may be in the bones of the face, or in 

 some of the smaller articulations. We have it in sore shins, but not 

 often. In the human patient it is a common disease, and causes 

 intense pain. It is not only dead but literally buried. It shows the 

 wonderful reparative powers of nature. A large bone may die and its 

 place be taken by new bone, which presents much the same appear- 

 ance as the former bone ; but a horse is not often allowed to live long 

 enough to reproduce an entire large bone. We frequently meet with 

 this in open joint. When a part of the bone dies it stimulates the 

 surrounding parts, and there is thrown out more ne^ bone, and the 

 dead bone is carried off by exfoliation, but this is very tedious, and, 

 as a general thing, it must be removed by surgery. Necrosis is fre- 

 quently met with in the lower jaw, from the action of the bit. It 

 causes more or less swelling of the soft tissues ; suppuration results. 

 Notice, if you open an abscess in this part, and you may find small 

 portions of bone in the matter. If this takes place in the shaft of 

 some of the large bones the process is more complicated. 



Osteo Sarcoma. — This is a non-inflammatory disease of bone, and 

 is by no means uncommon in cattle ; and I believe it sometimes 

 occurs in the horse ; but I cannot recollect of such a case. It is gen- 

 erally due to some constitutional diathesis, of a scrofulous or tubercu- 

 lar character. The cavities found in the bone, if examined, will be 

 found to contain deposits — tubercular deposits. It usually attacks 

 the bones of the head, particularly the lower jaw ; but sometimes 

 attacks the upper jaw, or almost any bone. If animals, having this 

 scrofulous tendency, are exposed to any exciting cause, the disease is 

 easily set up. It usually makes its appearance upon the side, or lower 



