On July 3, two rock climbers were in a remote area near Malibu Creek Canyon when they found a heartbreaking sight: a distressed 7-year-old German shepherd whose muzzle was shut with a zip tie.

They stopped to help the dog, taking the time to gain his trust so they could remove the zip tie. The dog warmed up to them after they freed his mouth and gave him some food.

“He is such a sweet dog,” Jonathan Manaoat, one of the hikers, told KTLA. “He allowed my friend and I to pet him and he gently ate our food out of our hands.”

They were shocked that the dog had been a victim of such cruelty: “Someone did this intentionally,” Manaoat told the outlet. “They left him stranded, down a hill in the middle of nowhere off the side of the road. They left him suffering. They left him for dead.”

The dog also had inflammation and warts around his body, and its suspected he was exposed to poison oak.

Deputies from the Los Angeles County Sheriff’s Department responded to a call and brought the dog to Palmdale Animal Care Center for treatment. He was then placed in the care of Los Angeles County Animal Care & Control’s Agoura Animal Center.

According to a press release from In Defense of Animals, the dog, now named Argon, is undergoing tests for suspected lymphoma. Despite everything, Argon has been a sweet and gentle dog and has been receiving lots of love and care.

It is still unknown who tied up Argon’s muzzle and left him in the middle of nowhere on that hot summer day, but animal groups have been pooling a substantial reward for anyone who comes forward with information about the crime.

In Defense of Animals, Peace 4 Animals and Hollywood producer Marc Gurvitz are collectively offering a reward of $12,000 for info, according to the press release. Anyone with information regarding the case are urged to contact 415-879-6879.

“We are grateful for the quick actions of these hikers and law enforcement, but our efforts must continue,” said Fleur Dawes, Communications Director of In Defense of Animals. “Argon was left to suffer and die in a remote location. We urge anyone with information about this cruel act to come forward. We are determined to find the person responsible for this horrific abuse and hold them accountable since they are a danger to others.”

“This cruel and heartless act of abandoning an innocent German Shepherd in scorching temperatures with his mouth zip-tied over the 4th of July weekend is reprehensible. The individual responsible must be swiftly and decisively brought to justice to the fullest extent of the law. Rest assured, justice will prevail!” said Katie Cleary, Founder of Peace 4 Animals and World Animal News.