656 Actinomycosis. 



contain minute yellowisli points and small cavities wliicli sug- 

 gest on cross section the appearance of a sieve or a sponge. 

 Tumors occurring in the region of the elbow , or under the 

 abdominal wall have a similar structure. 



Actinomycosis of the tonsils is also frequent (Johne). 

 This may be followed by abscess formation in the peri- 

 pharyngeal connective tissue. The maxillary bones, the larynx, 

 the lungs and occasionally other bones may also become affected 

 in swine. Metastatic infection may occur in various internal 

 organs, the pathologico-anatomical changes being similar to 

 those observed in cattle, with the difference, however, that 

 actinomycosis of swine, like the disease in human beings, fre- 

 quently manifests itself in the form of extensive suppurations 

 which may extend to the subcutaneous retropharyngeal and 

 prevertebral connective tissue, causing a breaking down of the 

 tissue elements and leading to the ultimate formation of ab- 

 scesses and fistulous canals under the serous membranes and 

 the glands. This destructive process may extend from the 

 prevertebral connective tissue to the vertebrae themselves. As 

 a result the periosteum of the latter is destroyed. They be- 

 come rough and soft from loss of tissue, and their spongy 

 substance contains small pus foci. In this manner the process 

 may spread from the retropharyngeal connective tissue, fol- 

 lowing the course of the prevertebral connective tissue along 

 the back or to the mediastinum, and after destruction of the 

 bodies of the vertebrae into the vertebral canal itself. 



In actinomycosis of the tongue its parenchyma contains 

 abscesses approaching a hazelnut in size and consisting of 

 coagulated masses of pus containing actinomyces colonies, or 

 of a conglomeration of actinomyces colonies 6.0 mm. or less 

 in length and surrounded by a connective capsule (HoUandt 

 observed such lesions in 11 out of 170 tongues). 



In the generalized form of actinomycosis there are now 

 and then metastatic abscesses in almost any of the organs, 

 including the brain, the bones, the lymph glands and serous 

 membranes. The primary focus" may have its seat in the 

 mucous membrane of the digestive tract or in the skin (Knoll,- 

 Carl, Zietschmann, Assmann). 



In sheep and goats actinomycosis is very rare, but when 

 present, it is usually found in the tongue. In exceptional cases 

 the lips, the jaws and the lungs may also be affected. (Berg 

 observed three cases among 400,000 sheep. Zala-Szent-Groth 

 observed the disease in the tongue of three sheep in a flock of 

 42.) The pathological changes are similar to those in cattle. 



Fumagalli observed the disease in a dog in the form of 

 a firm swelling of the gums (epulis) about the size of a walnut, 

 while Rossi found numerous nodules in the lungs of two cats 

 40 days, old. The lungs of one of these contained a mass of 

 firm connective tissue studded with actinomyces colonies, some 

 of which were calcified. 



