CANCEROUS TROUT

New Zealand Mail, Issue 1679, 4 May 1904, Page 76 (Supplement)

CANCEROUS TROUT

SOME INTERESTING OBSERVATIONS With reference to the specimens of cancerous trouit recently sent Home, frozen in ice, by Mr Gilruith, Chief Government Veterinarian, and Mr Ayson, Inspector of Fisheries, to Dr Bashford, director of the CanceT Research Fund. England, and mention of which was made in the "Times" last week, some interesting observations were made by Mr Ay son, now in Auckland, to a “New Zealand Herald?’ interviewer. Mr Ayson said the discovery was not a new one. I first noticed this gill disease in 1390, among the American brook trout (Salvelinus fontinalis), at the Masterton trout hatchery. The disease was at first peculiar to this fish until the rainbow trout. (Salimo iridens) were introduced, and among them it made its appearance when the fish were three years old. I have never found any in the English brown trout (Salmo fario), but. I found three Loch Leven trout (Salmo levenensis) affected in 1896. These fish were all from three to four years old and the three were collected from 1000 fish taken in 1896. In 1898 about two per cent, of He American brook trout over three years of age would be affected, and about one per cent, of rainbow front over that age. I never heard of a solitary instance Of the disease occurring in wild fish either in the S.kith

or the North Island;, no case, in short, except among fish confined in the h.-iteh-eries fish that axe kept there for breeding purposes. The largest percentage of the fish affected were the rainbow trout and the American brook trout.” And to what do you attribute the disease aoruong the fish you have specified, and which are stock fish, kept at the hatcheries ? “It is, I believe, due to the artificial life that they lead, to artificial food, tiie principal part of which is minced sheep's plucks and bullock's liver.'' Can you establish any connection between the disease and tnis food? “Well, at the Government salmon hatcheries at Hakateramea, a certain proportion of sheep's plucks are used, but a considerable part of the food used is a patented preparation made from the flesh of certain sea fish imported from Home. So far there has been no appearance of the disease among the salmon there. We have sent some of this food to be used by the Otago Acclimatisation Society in its hatcneries.” Is not your discovery likely to be of considerable service in the elucidation of cancer*, the cause of which, when known, is considered to be the first step towards its cure? “It is impossible to say how important a bearing this discovery of cancer in brood trout may have on this vast subject. You will have seen that Mr Gilrutli, the Chief Government Veterinarian, has already sent specimens of the affected parts of fish to Dr nashford, director of the Cancer Research Jfund *n England, and some affected trout have been sent to Dr Bashford, preserved in ice. It 4s impossible to foretell at this stage the important issues hanging upon this investigation, not only for New Zealand, but for the whole world. So far as we here are immediately concerned, II would conclude with a summary of my remarks: (1) That the disease has not been found among fisn in the wild state; (2; that it is confined to the liatchemes; (3) that no case has been found among the English brown trout; (4) that it»is chiefly American brook trout and next rainbow trout that are affected; (5) that only three instances of Loch Leven. trout have been . brought bo my notice—rand I am certain to have heard of other cases of any disease sooner or late; and (6) that no fish have been found diseased under three years old.”