Total intravenous anaesthesia with propofol-racemic ketamine and propofol-S-ketamine: a comparative study and haemodynamic evaluation in dogs undergoing ovariohysterectomy - Intelizano, Tatiana Regina; Kitahara, Flávia Rumi; Otsuki, Denise Aya; Fantoni, Denise Tabacchi; Auler Júnior, José Otávio Costa; Cortopassi, Silvia Renata Gaido (Pesquisa Veterinária Brasileira, 2008)