Silveira, S.D. et al. 2018. Preoperative electrocardiographic study of dogs at the veterinary hospital of Pontifícia Universidade Católica do Paraná. Brazilian Animal Science/ Ciência Animal Brasileira. 19, (Apr. 2018), 1–12. DOI:https://doi.org/10.1590/1809-6891v19e-49000.