SASKATOON -- The city's zoo is saying goodbye to a grey wolf that resided there for over a decade.

Zeppelin, a grey wolf that arrived at the Saskatoon Forestry Farm Park & Zoon in 2007, was euthanized on Thursday.

"It is always difficult to make a decision like this when it comes to the animals that we care for," zoo manager Jeff Mitchell said in a news release.

Zeppelin had faced arthritis-related issues over the past few years that until recently had been managed through veterinary care, the zoo said.

In recent months medication was no longer able to keep him pain-free.

"Zeppelin had an amazing life here at the Zoo and will be remembered for his spunkiness and adventurous nature."

A grey wolf has an average life expectancy of six to eight years in the wild but can live for up to 15 years in the care of a zoo, the release said.

Zeppelin was euthanized after consultations with veterinarians and his care team.

He leaves behind Buddy, his "life-long companion" at the zoo. The two wolves formed a close relationship soon after Zeppelin's arrival.

Buddy is experiencing age-related health issues similar to those Zeppelin faced, according to the zoo.

“We know that this will be an especially tough time for Buddy,” Mitchell said.

“We are going to do everything we can to help him adjust to being a lone wolf. Our animal care team has developed a plan to give Buddy as much attention and enrichment as he needs.”

In early April, the zoo also said farewll to another longtime resident, Jethro the cougar, after he died from hypertrophic cardiac disease.