336 ACTINOMYCOSIS. 



to the former, and starting from about its centre. The fascia under- 

 lying the skin is divided and separated as far as possible from the 

 parotid. The gland, thus exposed, is now separated from its sur- 

 roundings, beginning at the lower end, so that large bleeding vessels 

 may be more easily dealt with. For the same purpose a thread 

 may be passed around the carotid, which, in case of need, can be 

 used as a ligature. As the recurrent nerve may easily be injured 

 it is better, in valuable horses, to avoid exposing the carotid. The 

 gland should as far as possible be separated with blunt instruments, 

 assisted by the fingers. Vessels are ligatured as exposed, the larger 

 doubly ligatured and then cut through. In this way, and by free 

 use of sponges or dossils of lint, the field of operation is kept clear, 

 and the gland removed without dangerous bleeding. The wound is 

 then cleansed with antiseptic fluids, dusted with iodoform, covered 

 with jute or wood wool, and the edges brought together with sutures. 

 In twenty-four to forty-eight hours the stitches are loosened, the 

 dressings removed, the wound washed out, dusted with iodoform 

 and tannin, and the whole treated as an open wound. Healing 

 should be complete in three or four weeks. If during the next few 

 days portions of the wound appear damp, they should be dried with 

 wadding, and powdered with a mixture of iodoform and tannin (1 — 3). 

 Where a dry scab has formed, the wound is better left undisturbed. 

 Dry scabs, firmly adherent to the underlying tissues, should under 

 no circumstances be removed. 



(7.) ACTINOMYCOSIS IN THE PAROTID REGION. 



Although actinomycosis of the parotid region is also occasionally 

 seen in horses and swine, it is very much commoner in cattle. By 

 proliferation of the connective tissue new growths are slowly formed 

 in the subparotideal and retropharyngeal regions. These were 

 formerly erroneously regarded as tumours. Their true cause is to 

 be sought in local infection with the actinomyces or ray fungus. 



The fungus is probably taken in with the food, and finds entrance 

 into the mucous membrane and deeper-lying tissues through wounds 

 caused by the rough character of the food. The circumstance that 

 herbivora most frequently suffer from the disease, supports the theory 

 that infection results in this way. Johne detected vegetable material 

 invaded by actinomyces in the tonsils of swine ; Grawitz in the 

 lower jaw of a calf found portions of a head of corn, which were 

 surrounded by granulation tissue. Bang found the disease more 



