Chapinal, N., Fitzpatrick, C. E., Leslie, K. E. and Wagner, S. A. 2014. Short Communication: Automated assessment of the effect of flunixin meglumine on rumination in dairy cows with endotoxin-induced mastitis. Can. J. Anim. Sci. 94: 21-25. The objective was to evaluate the use of rumination loggers to monitor the effect of flunixin meglumine on rumination in lactating dairy cows with endotoxin-induced clinical mastitis. Mastitis was induced in 13 cows by intramammary infusion of Escherichia coli lipopolysaccharide (LPS) into a rear quarter. Four hours later, seven cows received flunixin meglumine intravenously and six received a saline solution. Control cows ruminated less than treated cows 5-8 h and 11-12 h after LPS infusion, although they ruminated more 15-16 h after LPS infusion. Rumination loggers show promise as a practical on-farm tool to monitor the efficacy of anti-inflammatory therapy for clinical mastitis.