updated 05/13/2013 AT 12:05 PM ET
•originally published 05/13/2013 AT 5:00 PM ET
Well, someone’s ready for swimsuit season!
The pooch, who weighed in at 77 lbs. at his heaviest, flaunted his 40 lbs.-slimmer physique during a Mother’s Day hike documented on his Facebook page by his foster mom-turned-owner, Nora Vanatta.
Since undergoing surgery at the beginning of the month to remove the excess skin between his legs due to his weight loss, Obie has stayed on the move, educating students about staying in shape, reported Today. And his own health goals remain at the forefront: Obie still has about 7 lbs. to lose from his 35 lb.-frame.
“He still has some work to do,” Vanatta previously wrote, “but is well on his way.”