Published online by Cambridge University Press: 01 June 2009
In recent years the attention of those interested in all aspects of the dairy industry has been focused upon the subject of mastitis, particularly the chronic streptococcal type. On account of the wide distribution of this disease and its adverse effect upon milk and milk products, it has become urgently necessary for the producer, distributor and manufacturer to be able to recognize mastitis in the cow and its effect upon the milk. It is, therefore, desirable that all those interested in dairying should be as fully informed upon the subject as possible. Many simple tests for the detection of mastitis have been described and are in common use, although so many papers have been published showing their limitations that it is surprising that workers should continue to use them(1, 2, 3, 9). Opportunity has been afforded to the writers to make an extensive examination and comparison of such, tests, with the main object of finding out if any simple test, or combination of simple tests, is really satisfactory for the diagnosis of chronic streptococcal mastitis. The enormous literature upon mastitis (much of it uncritical and, therefore, of little use) makes an adequate summary impossible, even if it were desirable in a paper of this nature, but reference may be made to a useful summary by Munch-Petersen (1).