A dog was attacked by a cougar on a hiking trail near Canmore and the cat had to be euthanized by conservation officers.

Officials say three mountain bikers from B.C. were riding downhill on the Highline Trail when their dog was attacked by the cougar.

The cyclists threw rocks at the cougar and yelled at it but it still did not run away.

Alberta Parks says this is extremely unusual behavior for a cougar and it is the fourth or fifth incident with this animal.

The young cougar and its sibling were orphaned at a young age and they likely didn't learn hunting skills or to avoid people.

They believe that the cougar was also starving.

"The Highline Trail is up on the mountain side, and we are now in their territory, so it's hiker/biker beware, and making lots of noise, and just being aware that you are out in wildlife territory," said Canmore resident, Jane Pearson.

Conservation officers had to put the cat down.

"It's a very hard decision to make and none of us take it lightly, so we tried everything that we possibly could to see if there was anything we could do with this cat before we made that hard decision, but we had to do it," said Glen Naylor with Alberta Parks.

Park officials say they contacted the Calgary Zoo to see if the cougar could be moved there, but unfortunately that didn't work out.