338 TUMORS. 



comes swollen considerably on one or both sides. The membrane 

 over the swelling is red, feverish, and painful to pressure. The 

 animal makes frequent attempts to defecate without any result. A 

 local examination shows the presence of a discharge of purulent 

 matter from the orifice. This condition is soon relieved by means 

 of cooliag applications and frequent emptying of the pouch. 



(6) Goitre; Struma. Goitre is a non-inflammatory swelling of 

 the thyroid gland, and is frequently seen in the dog as a simple 

 hyperEemia and enlargement. In some cases we find an adenoma 

 of the thyroid gland (true goitre). In very rare cases we find a 

 sarcomatous or carcinomatous deposit of the thyroid gland (false, 

 malignant goitre). It has been observed that in 30 or 40 per cent. 

 of tumors in old dogs the disease is a cancerous degeneration of 

 the thyroid gland. 



The thyroid gland in the dog consists of two portions, lying on 

 each side of the trachea, separated by the median line, a short dis- 

 tance below the larynx, and connected in the larger animals by a 

 narrow isthmus. In small dogs this connection may be absent. 

 We generally speak of two thyroid glands in the dog, and more 

 so because we occasionally find only one side diseased, and very 

 frequently find one portion more affected than the other. 



"We divide goitre into three varieties: the hard, soft, and cystic 

 forms. A tumor of the neck is the symptom of all three varieties, 

 which may sink downward as far as the entrance of the chest. 

 As soon as goitres reach any development they may cause alarm- 

 ing symptoms, such as difficulty in respiration by pressure on the 

 trachea, and, in rare cases, dysphagia. Leisering saw a goitre in 

 a poodle dog which extended from the larynx to the sternum, and 

 covered almost the whole lower surface. It was about 16 cm. long, 

 10 cm. wide, and 3 cm. thick. 



The hard goitre (struma fibrosa) is a fibrous hypertrophy of the 

 gland and a disappearance of the glandular substance. The swell- 

 ing is hard and firm. In the soft form of goitre (struma mollis) 

 there is more or less hyperplasia of the glandular tissue. In the 

 cystic goitre (struma cystica) the gland is altered into ona or more 

 fluctuating cavities, which, as a rule, are filled with a colloid fluid. 

 There are other varieties of this tumor, but the writer refers you 

 to the text-books on pathological anatomy. 



Carcinoma and sarcoma of the thyroid gland are distinguished 



