Henrique, F.V., Parentoni, R.N., de Medeiros, L.K.G., Brasil, A.W. de L., de Oliveira, K.D.S., do Rego, R.O., de Souza, A.P. and da Nóbrega Neto, P.I. 2018. Preoperative epidural administration of morphine or methadone for analgesia in female dogs undergoing to ovariohysterectomy. Brazilian Journal of Veterinary Medicine. 39, 1 (Mar. 2018), 46–53. DOI:https://doi.org/10.29374/2527-2179.bjvm0253.