The German Shepherd that was rescued from death last week by the Best Friends Animal Society was put down on Sunday.

Bela fell ill just days after arriving in Utah from Indiana, and a fast-growing cancer was discovered in his lungs. Best Friends made the heartbreaking decision to have him euthanised. 

Bela captured the hearts of people around the world after his late owner decreed in her will that he should be sent to an animal sanctuary across the country or euthanised, cremated, and interred with her after her death.

Attorney Doug Denmore reported last month that Connie Lay's estate could not afford to send Bela to Best Friends, and it appeared that the dog would have to be put down. Once the story hit international news, however, a campaign began to save the animal.

A worker at the nation's largest no-kill animal sanctuary drove about 3,600 miles round-trip to bring Bela to Kanab last week. The society said that Bela had behavioural and other issues, but they were working with him to increase his chances of being adopted. 

It was not to be, however. 

"On Sunday morning Bela's caregiver noticed that his abdomen was distended and he was breathing rapidly, so he was brought to the Best Friends clinic for an emergency checkup," the society said in a statement. 

"Tests revealed fluid in his abdomen and also surrounding his heart. Most critically, X-rays revealed nodules in his lungs. Our medical director diagnosed Bela with a very fast-growing cancer and there was very little likelihood he would have lasted more than a very stressful day or so. 

"Reluctantly, Bela's caregiving team made the decision that euthanasia was the right option. This was a very difficult choice, as it is with any animal in our care, but we approached the decision from the perspective of what was the kindest course of action for Bela."

Bela will be cremated, and the ashes will be sent to Indiana so she can be interred with her late owner.