178 The Ohio Journal of Science [Vol. XVII, No. 6, 



who have made a study of fifteen old dogs, report a remarkable 

 series of multiple tumors. There were fourteen cases each of 

 tumor of the liver, spleen, and adrenals; eight cases each of 

 tumor of the gall-bladder and prostate ; five cases each of tumor 

 of the stomach and ovary; four of the subcutaneous tissues; 

 two cases each of the submaxillary gland, testes, and breast; 

 one case each of the following: pancreas, parotid, thymus, skin, 

 hypophysis, blood vessels and bladder. In only one of these 

 cases, that of a malignant tumor arising from the medulla of 

 the right adrenal, was there any metastatic manifestation found 

 and in this case there were metastatic nodules in the liver. All 

 the other tumors were primary. In five dogs of this series 

 there were also multiple carcinomas of the thyroid gland which 

 were primary. In three cases, both lobes were involved. 



Several other workers have reported cases of primary 

 carcinoma of the thyroid gland of dogs. Sarcomas are very 

 rare. Wells ('01) and Schoene ('09) have each reported a case 

 occurring in a dog in which the thyroid tumor was composed 

 of connective tissue and epithelium — the so-called sarco- 

 carcinomas. 



During the school year of 1915-16 a systematic search was 

 made for tumors occurring in the dogs used in the Laboratories 

 of Physiology and Pharmacology. Especial attention was given 

 to the thyroid gland. Every gland was routinely sectioned and 

 microscopical preparations were made. There are 234 glands 

 in this series. During the first four months of the present 

 school year (1916-17), 37 additional thyroid glands have been 

 routinely examined in the same way, making a total of 271 

 cases in the complete series. In these 271 thyroid glands, five 

 malignant tumors were encountered. This gives an incidence 

 of 1.8%. During the two previous years, such tumors as 

 attracted attention in these Laboratories were sent to the 

 Pathological Laboratory for examination. Five cancers of the 

 thyroid were observed in this way. At various times specimens 

 of tumors occurring in dogs have been presented to the labora- 

 tory. In this series are five cancers of the thyroid gland. No 

 sarcomas of the thyroid were encountered. This study is, 

 therefore, based upon fifteen specimens of carcinoma of the 

 thyroid of dogs. Since the specimens fall into four distinct 

 groups, individual protocols have been omitted and those cases 

 resembling each other closely have been described as a group. 



