264 DISEASES OF CATTLE. 



ing the part. The periosteum is well supplied with sensitive nerve 

 endings and when inflamed is very sensitive to pressure and may 

 cause lameness. This condition is often difficidt to determine, and 

 even an acute observer may fail to locate the point of its existence. 

 There are three forms of i^eriostitis — aseptic, purulent, and fibrous. 



AsKPTic PERIOSTITIS wlieu it becomes chronic causes such a bony 

 enlargement (exostosis) as is seen in the callous formation following 

 the fracture of a bone. The formation of such a tumor or enlarge- 

 ment on the surface of a bone is liable to occur in any part of the 

 bone covered with periosteum, and when found near a joint involv- 

 ing two or more bones it is liable to result in their union (anchylosis). 



Treatment. — Applications of cold water to check the inflammatory 

 processes is indicated for the first few days in aseptic periostitis, 

 followed by hot fomentations to hurry resorption of fluids. Mas- 

 sage should then be given with camphor ointment, mercurial oint- 

 ment, soap liniment, or Lugol's solution. In the chronic form point 

 firing or a biniodid-of-mercury blister will be found beneficial. 



PuETTLENT PERIOSTITIS foUows wounds which reach the periosteum 

 and become infected, as observed in compound fractures, or it may 

 result from advancing purulent conditions in neighboring structures, 

 as in foul foot. It may also occur in the course of an infectious dis- 

 ease, when small abscesses are formed under the periosteum (sub- 

 periosteal abscess). It may lead to necrosis of the bone or a fistulous 

 track from the bone to the surface. There is usually much pain and 

 fever, and the odor from the wound is offensive. 



Treatrii-ent. — In this form of periostitis the periosteum should be 

 freely incised, followed either by continuous irrigation or frequent 

 injection of the wound with antiseptic solutions. 



Fibrous periostitis. — This form of the disease consists in the 

 thickening of the outer layer of the periosteum from the inflamma- 

 tion reaching it from neighboring structures. This newly formed 

 fibrous tissue may become ossified or may transmit the inflammation 

 to the deeper bony structures. It is frequently seen in cases in which 

 there has been an intense inflammation of the skin close to an 

 underlying bone. 



TreeUment. — The treatment should be the same as that recom- 

 mended for aseptic periostitis. 



OSTEOMYELITIS. 



This term refers to an inflammation of the bone marrow, which is 

 most commonly seen following the Ijacterial infection of a compound 

 fracture and usually results in pus formation. The bone is melted 

 aAvay and pus escapes from the bone under the periosteum, involving 

 the soft tissues. It is princijially confined to the long bones and sel^ 

 dom affects more than one. 



