The dog found wandering the streets after being shot in the head is recovering at his foster home after another surgery.
Boulder County Animal Control found the dog, now called Beefcakes, on July 7.
A deputy with the Boulder County Sheriff's Office said even though the dog was seriously injured, he was still extremely friendly when the deputy took him to Aspen Meadow Veterinary Specialists.
Vets said the dog had been shot at close range. The bullet fractured the dog's jaw bone in multiple locations.
Beefcakes went through three surgeries this summer to repair the damage.
"Despite the trauma that he has endured, Beefcakes has a truly beautiful and happy spirit," the Longmont Humane Society wrote on its Facebook page back in July. "This wonderful fellow is stealing the hearts of everyone he meets here at the shelter with his loving and outgoing nature."
Beefcakes went through surgery again on Dec. 1 for a heart murmur, this time at Alpen Glow Veterinary Specialists.
"Improvement was made as a result of the procedure and Beefcakes is now recovering quietly in his foster home," the humane society said in a post this week. "Once he has been cleared by our medical team, he will then become available for adoption. Thank you to everyone for your concern and well wishes for Beefcakes. He is a truly resilient boy!"
Russell William Middleton, 38, was arrested on three felony charges and one misdemeanor charge, according to the Boulder County Sheriff's Office.
Deputies have not said how Middleton is connected to the dog.