ABSTRACT
To study the effectiveness of intramammary treatment of clinical mastitis in cattle, three different suspensions containing antibiotics for intramammary injection were compared in a field trial in the provinces of Friesland and North Brabant. Milk samples from the clinically abnormal as well as from the clinically normal quarters were examined for pathogenic bacteria and cell counts were made prior to treatment, within one week after treatment and within three weeks after treatment. The clinical diagnosis was confirmed by laboratory studies in approximately 90 per cent of the cases in which quarters were abnormal. However, 50 per cent of the clinically normal quarters also showed increased cell counts and/or bacterial infection. Treatment of these quarters should therefore be considered. Apart from regional variations as regards the character of the mastitis and the results of treatment, there were no significant differences between the effects of the three suspensions. Clinical recovery occurred in approximately 90 per cent of the cases, the pathogenic bacteria disappeared in approximately 75 per cent of the cases and the increased cell counts were restored to normal in approximately 60 per cent of the abnormal quarters.
