Willow, a joyful standard poodle with a heart as big as her fluffy tail, trotted beside her dad, Peter, along their usual trail in Eagan, Minnesota. The wildlife had always kept its distance—until it didn’t.

Summer brings sunshine, long walks, and backyard adventures—but for dogs, it also brings serious risks. Unlike humans, dogs don’t sweat through their skin. They cool down primarily by panting and through their paw pads, which makes them especially vulnerable to overheating in hot and humid conditions.

Meet Ellie. Ellie is a sophomore at the University of Oregon and joined the Mission Animal Hospital volunteer team just over one month...