155 



The Experimental Transmission of Goitre from Man to Animals. 

 By Robert McCarrison, M.D., M.E.O.P. (Lond.), Captain, Indian Medical 

 Service ; Agency Surgeon, G-ilgit, Kashmere. 



(Communicated by Major Ronald Ross, C.B., F.R.S. Received May 3, — Read 

 June 1, 1911.) 



[Plate 1*.] 



Experiments had repeatedly been carried out on dogs to test the assump- 

 tion that goitre could be conveyed from man to animals by faecal infection of 

 the water supply, but with negative results. In the present experiments 

 female goats were employed. The drinking water supplied to these goats was 

 fouled by passing through a specially constructed box, which contained 

 sterilised soil mixed with the faeces of goitrous individuals. In the case of 

 one batch of six goats, only this water was consumed. In the case of 

 another batch of seven goats the box above referred to contained, in 

 addition to the sterilised soil and faeces, 500 earthworms. These were 

 added on the assumption that they might act as intermediate hosts to 

 the infecting agent of the disease. The goats consumed this highly polluted 

 water for 64 days, from October 13 to December 15, 1910. The results 

 observed were (1) a loss of weight, due doubtless to confinement in a 

 small hut for the 64 days of the experiment ; (2) that many of them 

 suffered from diarrhoea ; and (3) that 50 per cent, of the animals showed 

 enlargements of the thyroid gland, most marked on the right side. The 

 thyroids of three control goats showed no alteration in size. 



The enlargement of the thyroid was observed to fluctuate in size consider- 

 ably, a fact which had previously been noted in the case of experimentally 

 produced goitre in man. The average weight of the normal thyroid of the 

 goat in Gilgit is 1/10,000 part of the body weight. The enlarged glands of 

 the goats in the experiment were found to weigh from 1/4,272 to 

 1/7,000 part of the body weight. In both batches drinking fouled water 

 the results observed were the same. 



Microscopical examination of the enlarged organs showed varying degrees 

 of dilatation of the vesicles, scarcity or almost complete disappearance of the 

 masses of cells lying between the vesicles, while no alterations were observed 

 to have taken place in the connective tissue stroma of the enlarged glands. 

 The hypertrophy was due wholly to distension of the vesicle with colloid, 

 and the formation of new vesicles from the intravesicular masses of cells. It 

 is concluded that — 



VOL. LXXXIV. — B. N 



