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GOITRE : 
follicles of the thyroid gland, with colloid change of their con¬ 
tents, which are chiefly albuminous. The swelling is mainly due to 
enlargement of the follicles, and is termed struma follicularis. It may 
attack the entire organ or only one-half, less frequently it is confined 
to certain sections. (2) In fibrous goitre the connective tissue is 
specially increased, the follicles, on the other hand, being little affected. 
This form is generally confined to single portions of the gland, and 
seems more often to be of an inflammatory character. (8) The gland is 
exceedingly rich in blood-vessels, and these, especially the veins, become 
greatly dilated, causing varicose goitre (struma varicosa). (4) At times 
single follicles undergo distension, producing the so-called cystic goitre 
(struma cystica). 
Specific new growths, like carcinoma, have been seen in dogs by 
Bruckmiiller, Zschokke, and others. Zschokke says that at least 80 
to 40 per cent, of old dogs suffer from goitre, and whilst in young 
animals the condition consists simply of hyperplasia of the gland, the 
goitre of old dogs is almost always of a cancerous nature, and is prone to 
degeneration and bleeding. Gerlach and Honert found sarcoma of the 
gland in horses. Tuberculous swellings have been met with by Bruck- 
miiller and others in cattle. Johne has described carcinoma of the 
thyroid, accompanied by secondary carcinoma in the lungs of a horse. 
But the older reports of these growths are not absolutely reliable, as the 
classification of tumours was not then so precise as now. 
The causes of goitre are just as little known as those of other tumours. 
Endemic outbreaks are stated to have occurred in animals as in men 
(Baillanger in mules, Worz in cattle). French veterinarians have further 
insisted that in regions where goitre frequently occurs in men, it is also 
common in animals. That locality has some predisposing effect seems 
undeniable, but complete uncertainty exists as to the immediate cause of 
the disease. Whether the existence of magnesia or the absence of iodine 
and bromine in the soil exercises any influence, as has been asserted, is at 
present undecided. Little is known of the connection of goitre with 
cretinism, no veterinary statistics being available. 
In animals, and especially in carnivora, goitre appears most frequently 
during the earlier years of life. Without doubt it may, under certain 
circumstances, be inherited, and Moller has repeatedly seen almost all 
the puppies of one litter affected. Lydtin related the case of a stallion 
which transmitted goitre to five of his offspring. Johne saw a case of 
inherited goitre in the dromedary. According to Haubner, the lambs of 
one flock were attacked enzootically in certain years. In one season six, 
and in the following, ten new-born lambs were affected, and the disease, 
it was believed, was transmitted by the ram. Similar observations have 
been made by Gurlt in goats. It should, however, be noted that the size 
