07/19/2013 11:19 EDT

John Unger And Schoep: Internet-Famous Dog From Heartwarming Picture In Lake Superior Dies

John Unger and his dog Schoep have finally been parted.

The pair seemed to define the bond between humans and animals with a single iconic photograph that made the internet swoon.

On Thursday, Unger left this simple message on his Facebook page: "I breathe but I can't catch my breath... Schoep passed yesterday."

Schoep was 19-years-old and riddled with arthritis when Unger, a Wisconsin resident, started taking him into the waters of Lake Superior, hoping the swim would help his friend sleep.

It seemed to work, as Schoep, rather unforgettably, fell asleep in Unger's arms.

A photographer and friend to Unger captured the moment, along with the hearts of people around the world -- with this image:

Last August, photographer Hannah Stonehouse Hudson told the Huffington Post, "This photo was from a last minute session. We had been trying to get together for weeks... We finally got together last Tuesday (the 31st). I had about 5 minutes to shoot and this is what I caught -- a man and his dog. John loving his Schoep, and Schoep trusting John so much he falls asleep in the buoyancy of the water. This is in no way posed. I hate posed photos. They never, ever capture the true essence of anything."

Back then, Unger feared that his faithful companion would not be able to battle on for much longer. He imagined Stonehouse's images would be the last of the pair together.

But after the image exploded on the internet, so too did the support. Enough donations flowed in for Unger to pay for extensive and more effective therapy.

“As best as I can guess, the treatments have turned back the clock on his life about a year-and-a-half to two years,’’ Unger told in September 2012. “I’ve taken him for walks on trails that we haven’t been on in three years. He’s not dragging his back legs like he was before. To be able to do that again with him, words can’t even describe the feeling.’’

Seizing on Schoep's newfound fame, Unger established the Schoep Legacy Foundation for owners struggling to pay for pet care.

The clock, however, could only be held back for so long.

Facebook fans wasted no time in offering condolences.

"What a wonderful, loving and compassionate companion you were to Schoep," wrote Dianne Lambert. "He was lucky and so were you."

"Dearest Schoep is running free and out of pain," Tanner Hutchinson wrote. "Rest dear boy, you were very much loved.

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