Updated

An aging dog --who gained national attention when a photo of his owner cradling him in Lake Superior went viral--  has died.

The picture featured Schoep, a 20-year-old shepherd mix who was severely arthritic, blind and hard of hearing, resting his head on the shoulder of his owner John Unger as the two waded through the water.

Unger posted on his Facebook page that his beloved dog died on Wednesday. “I Breathe But I Can’t Catch My Breath… Schoep passed yesterday,” the post read. A picture of the dog’s paw print in sand accompanied the post.

Unger rescued Schoep 20 years ago, and was looking for ways to relieve the dog’s pain. A friend captured one of their water sessions and the photo immediately went viral, with people sending donations to help pay for Schoep's medical bills. Unger kept Schoep’s fans updated on his condition posting regularly to Facebook. The page has been flooded with tributes to the dog as news of his death spreads.

The Associated Press contributed to this report.