TUMORS, PARTICULARLY THOSE OF THE SKIN. 



A thorough description of tumors, with the different varieties and 

 forms, cannot be discussed here as explicitly as the writer would like, 

 and he therefore will confine himself to such tumors as are met with in 

 general practice, and for further details would direct the reader to books 

 on general pathology and morbid anatomy. 



Tumors are rather common in the dog. Of the various neoformations 

 carcinoma seems to be the most frequently seen. Next is the fibroma, 

 then the papilloma and the sarcoma, and the lipoma, the latter being 

 comparatively rare. Regarding the frecjuency of cancer, out of over 

 twelve hundred dogs only about 5 1 /2 per cent, were affected with 

 cancer, and of the organs attacked they were in the following order: 

 Respiratory apparatus, 26 per cent.; urino-generative apparatus, 26 

 per cent, digestive apparatus, 25 per cent., and the skin, 20 per cent. 

 As regards age, Frohner found that 15 per cent, were in animals under 

 five years of age, 25 per cent, between the ages of five and six, 34 per 

 cent.; between seven and eight years, and 18 per cent, l^etween nine and 

 ten years, while 4 per cent, were between eleven and thirteen years. 

 No animal under two years was found to be affected with cancer. 



The following tumors are found in the dog: 



1. The Fibroma. — This neoformation occurs rather frequently in 

 the dog, the most frequent location being in the skin and subcutis of the 

 head, neck, abdomen and spine. Fibromata are also found on the chest 

 and extremities. They may occur singly or in large numbers. They 

 may be hard or soft according to the amount of intercellular tissue they 

 contain. They are usually clearly outlined, rounded with a smooth 

 surface (fibroma durum), more rarely soft in consistence, and not so 

 w^ell circumscribed (fibroma molle, fibroma moUuscum). The latter 

 is frequently bluish-red with a network of veins on its surface. The 

 filjroma frequently hangs down, particularly when it is in an inferior 

 portion of the body, like the abdomen (fibroma pendulum) (Fig. 174). 

 In parts where there is slight movement of the skin, and the cutis is 

 firmly fixed, such as the ear or metatarsus, the fibroma assumes a flat, 

 circular, coin-like appearance, and has a rough or granular surface. In 

 some cases there is tumefaction of the skin, as on the edge of the nose, 

 elbow, tuberosity of the ischium, the outer part of the forearm, knee and 

 legs. These callosities are usually called recumbent, bed or kennel 

 tumors. They are generally bluish-gray or grayish-red in color, rough- 



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