2017 ACVIM Forum Research Abstract Program

Initial assessment of high dose dipyrone was well tolerated in horses when administered twice daily for 15 days. Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma. Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. TX has been shown to induce early apoptosis of peripheral blood and bronchoalveolar lavage (BAL) neutrophils from horses with acute lung inflammation (Perez et al., 2016) . Our study group previously showed that neutrophil respiratory burst and IL-8-induced chemotaxis also decrease after treatment with TX, confirming a direct action of the drug on the cell type (Borlone et al., 2017) .