A repeated measures design was used to analyze the effect of a canine interaction on salivary cortisol and immunoglobulin A (IgA) in 33 adults; 16 were pet owners and 17 were non-pet owners. Cortisol and IgA levels before and after a canine interaction (experimental) or viewing a canine movie (control) were measured by enzyme-linked immunosorbent assay and spectrophotometer. Data show a significant interaction effect for salivary cortisol in non-pet owners (p = 0.003). Changes in IgA levels were not significant. The findings suggested that interaction with canines may help reduce the biological effects of stress that influences human health. Further studies with larger sample sizes are necessary to support these results.