Liver vitamin A levels and periodontal disease in ewes

Authors: Brown RA, Rammell CG, Cunliffe B, Orr MB
Publication: New Zealand Veterinary Journal, Volume 31, Issue 11, pp 204-205, Nov 1983
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Alimentary system/gastroenterology, Diet/rations/food, Nutrition/metabolism, Oral/teeth, Disease/defect, Vitamins
Article class: Correspondence

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Abstract: Periodontal disease of the incisors (PD) is very common among hill sheep in Otago and Southland. The characteristic clinical signs are loosening and loss of permanent incisors with, frequently, incisor lengthening and protrusion in front of the upper dental pad. In the late `60s and early `70s W.L. Porter studied PD extensively. He found that the feeding of winter root crops exacerbated the condition, but possible primary causes such as selenium deficiency, lack of dental exercise and dietary oestrogenism were tested with negative results. The cause of the disease remains unknown. Porter however considered that ‘excessive intake of carotene by sheep grazing rapidly growing pasture may be aetiologically important through an effect on bone salt metabolism`. Lush green feed as in most autumn pasture in Otago/Southland is very rich in carotene. During transit through the intestinal wall, carotene is largely converted to vitamin A and stored in the liver. To investigate the hypothesis that hypervitaminosis A is involved in the pathogenesis of PD, the liver vitamin A levels of ewes with good mouths and those with PD were compared…

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