Veterans PTSD Service Dogs (IMAGE) Purdue University Caption Kerri Rodriguez, human-animal interaction graduate student (left), and Maggie O'Haire, assistant professor of human-animal interaction in the College of Veterinary Medicine, look at cortisol samples. Cortisoal was one of the measurements used in a new study that shows how veterans with PTSD may benefit physiologically from using service dogs. Credit Purdue University photo/ Kevin Doerr) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.