Recent research has emphasized the health implications of acute or chronic stress in animals. Hospitalized dogs are susceptible to stress due to various factors, including exposure to a novel environment, invasive procedures, and separation from their primary caregiver. The clinical significance of stress in these animals underscores the importance of stress management from the moment of admission. However, there remains a lack of universal qualitative and quantitative indicators of stress in small animals, necessitating reliance on behavioral analysis and stress marker assessment for accurate diagnosis. Among these markers, cardiovascular parameters such as heart rate and systolic blood pressure are commonly used, although their interpretation can be influenced by various factors. The aim of the study was to assess the impact of appeasing pheromone on cardiovascular parameters in hospitalized dogs. Ten healthy dogs were selected for a prospective, paired, randomized, and double-blinded. The dogs were submitted to two experimental protocols: pheromone administration and placebo. The cardiovascular parameters were evaluated at baseline until the end of a 24-hour hospitalization period. The study evaluated ambulatory electrocardiography and systolic noninvasive blood pressure using a Doppler. Analysis of cardiovascular parameters revealed no significant difference in systolic blood pressure between groups, despite its elevation in both treatment conditions. In the placebo group, the maximum heart rate of the placebo group at the time baseline (T0) was lower compared to subsequent time points (T6, T12, T20), indicative of stress upon arrival in the hospital environment. Conversely, the pheromone group showed a higher mean heart rate at T20 compared to the placebo group. Additionally, the placebo group displayed a higher minimum heart rate at time baseline (T0) compared to later time points (T6, T12, T20, T24). At time T6, a higher minimum heart rate was observed in the pheromone group. Even though fluctuations were observed in mean and minimum heart rates during monitoring, they indicated no clinically relevant deviations. There was no difference in heart rate variability over time between the analyzed substances. Exposure to dog-appeasing pheromone through a diffuser presentation, therefore, did not lead to significant changes in cardiovascular parameters related to stress reduction in hospitalized dogs.