can petting animals lower blood pressure?

Reduce stress.
Research has shown that simply petting a dog lowers the stress hormone cortisol , while the social interaction between people and their dogs actually increases levels of the feel-good hormone oxytocin (the same hormone that bonds mothers to babies).

In fact, an astonishing 84 percent of post-traumatic stress disorder patients paired with a service dog reported a significant reduction in symptoms, and 40 percent were able to decrease their medications, reported a recent survey.