Variabilidade da frequência cardíaca, estresse oxidativo e caracterização do sono em período noturno de cães braquicefálicos e mesocefálicos em ambientes domiciliar e hospitalar

Abstract

The environment is a crucial factor that can modify sleep dynamics. In humans, poor sleep quality in hospitalized patients is well documented, characterized by less sleep time and reduced quality. In dogs, the environment also significantly interferes with sleep, considerably reducing their rest period. Besides the arrhythmias caused by the environment, brachycephalic breeds are particularly predisposed to developing sleep disorders, such as apnea, due to partial airway obstruction common in these breeds. Both the environment and sleep disorders affect the physiological mechanisms of dogs. Heart rate variability (HRV) is an important tool for evaluating autonomic balance through heart rate fluctuations, serving as an indicator of stressful situations. Oxidative stress results from the imbalance between reactive oxygen species and the body's antioxidant mechanisms, which can be triggered by stressors such as the hospital environment and sleep disorders. Based on these premises, this dissertation is organized into two chapters, presented as scientific articles. The first article addresses heart rate variability and sleep characterization in brachycephalic and mesocephalic dogs in home and hospital environments. The second article examines oxidative stress in brachycephalic and mesocephalic dogs in these same environments. Through the studies, it was possible to evidence the absence of vagal stimulation in brachycephalic dogs, that the hospital environment has an effect on the generation of oxidative stress in both brachycephalic and mesocephalic dogs, that racial conformation and the environment do not affect nighttime sleep duration when comparing brachycephalic and mesocephalic dogs in home and hospital environments, and that the hospital environment does not affect heart rate variability in brachycephalic and mesocephalic dogs.