The geographic distribution of carcinomas of the small intestine in New Zealand sheep

Authors: Simpson BH
Publication: New Zealand Veterinary Journal, Volume 20, Issue 3, pp 24-28, Mar 1972
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Abdomen, Alimentary system/gastroenterology, Biosecurity, Disease surveillance, Epidemiology, Neoplasia, Oncology
Article class: Scientific Article

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Abstract: Prior to 1960, carcinomas of the intestine of sheep had been reported only rarely. Dodd (1960, 1964) reported a total of 51 cases of carcinomas of the ovine small intestine in material passing through a New Zealand diagnostic laboratory over a period of 7 years. Six of the 88 “wasting” sheep examined by Cook (1964) in New Zealand were affected by “neoplasia of the intestine”. The common occurrence of small intestinal carcinomas in ewes in New Zealand was confirmed by Webster (1966, 1967) who found lesions in 0.52% of slaughtered ewes, and in approximately 0.02% of hoggets and wethers. No cases were noted in over 200,000 slaughtered lambs. In Australia, McDonald and Leaver ( 1965) diagnosed carcinomas of the small intestine as the cause of death of 5 sheep on one property. They considered this disease was causing the death of 0.4% of all sheep and 2% of sheep over 5 years of age on that property, but could not locate the condition on surrounding farms. The only locality outside New Zealand in which relatively large numbers of these carcinomas are known to occur is Scotland. J. Norval (pers. comm.) found between 0.015 and 0.048% of sheep slaughtered at Edinburgh abattoir affected each year from 1962 to 1967. Norval stated that all cases diagnosed were in aged ewes, and as these constittited 15 to 20% of sheep killed the prevalence in ewes would have been approximately 0.2%. This contrasts markedly with the situation in Great Britain as a whole, as reported by Anderson et al (1969) who found only one carcinoma of the small intestine in 4.5 x 10⁶ sheep examined. The reports of prevalence of carcinomas of the small intestine in various parts of the world, together with the total lack of reports of their occurrence from many countries, suggested there might be an uneven world-wide distribution. It was decided, therefore, to investigate the geographic distribution of these neoplasms in New Zealand as part of an epidemiological study undertaken in an attempt to identify factors associated with their occurrence.

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