THe JOURNAL 



OF 



Yfie ©eparfment of ^gricufture. 



Vol. VI. Part 4. 



8th April, 1908. 



DISEASES OF FARM ANIMALS. 



{Coiitimicd from page i6o.) 



S. S. Cameron, M .R.C.V .S., Cliief Y eteriiiary OiJicer. 



VII.— ACCIDENTS AND INJURIES (conthiued). 



LUBRARV 





ABRASIONS, BRUISES, CONTUSIONS, AND 

 ABSCESSES. 



An ABRASION is an injury on tlie surface of the skin without rupture. 

 Sore shoulders are a common instance of abrasion in horses (see next 

 page). 



Bruises are injuries of the nature of a wound sustained beneath the 

 skin without breaking of the surface. Saddle and girth galls ])artake of 

 the nature of a bruise. 



The term ^'contusion " is usually applied to^ a deep seated brui.'^e or 

 to an injury of the substance of an internal organ without rupture of its 

 covenng. 



An ABSCESS is a closed cavitv in tissue enclo.sing a collection of 

 pus. It is formed as a result of a circumscribed suppurative inflammation 

 and has a tendency to increase in size — always in the direction of least 

 resistance, hence the " pointing " of absces.ses towards the skin or soft 

 structures. Abscesses may be caused in a variety of ways, as from liruises 

 or fractures, but the essential causative condition is the presence of one 

 of the common pus forming bacteria {StafJiylococcus pyogenes aureus or 

 albus). Their formation is almost alwavs accompanied by local pain, 

 swelling, heat and usuallv throbbing. The principal feature by which an 

 abscess may be distinguished from a non-suppurative swelling is that the 

 former is fluctuating while the latter usually "pits" on pressure. Ab- 

 scesses may be " acute " or " chronic " ; the former " come to a head " or 

 " point " quickly, while the latter are slow in reaching the bursting stage 

 and are usually surrounded by a dense wall of fibrous tissue. Fistulous 

 withers, poll e\il, shoulder tumors and the like are ordinarx instances of 

 abscess formation of varying degree and character. 



Occasion is now taken to describe in detail several of the conditions just 

 mentioned as a knoAvledge of their nature, and their successful treatment is 

 often a matter of considerable economic importance to the stock-owner. 



