We're on our third since 1991. As BillyGoatGruff said, the price for them is very high and the breeders for good dogs have become scarce.
KBD's are referred to as a primitive breed, so a little different than standard breeds like labs and goldens. They will have a strong hunt drive which can range from squirrels to bears, deer etc., just depends on the individual dog.
They have a tendency to range far and recall is very important to develop early using positive reinforcement. In fact all training should positive reinforcement, regardless. We use e-collars when on hikes and runs strictly for recall and 99% of time use the buzzer, shock mode (and set low) is only used when we know they are blatantly ignoring us and they need to get back quick and when they do come they get a reward, used maybe once or twice a year if that.
Their reputation like so many dog breeds is a bit exaggerated as to " bravery", " loyalty" etc. They're still dogs and each is an individual. Our first one was raised from a pup and was a cat hunting machine, very driven, and not so great with the neighbors. He did great around people and took to training well after we figured it out. Our second was a pound pup and had no time around people before we got him. He was a good hunter and trained fairly well too but was very aloof and took quite some time to warm up to people. Our third dog we have now was a rescue of sorts that came from a supposed service dog training facility directed at vets with ptsd. Unfortunately the way they were "training" the dogs and the environment in which they were living created ptsd in our dog. It took quite a while to get him straightened out and he will probably never be 100% Karelian. He is a goof ball and more like Ferdinand the bull than a stud KBD baying a grizzly. He does well on the trail and stays close by and follows commands pretty well but if he feels stressed for whatever reason he locks up like a mule and squats. After 4 years he still stresses traveling in a car. He has been great with the kids and is a big lover.
They need a fair amount of exercise everyday. Out in the woods off leash is best but recall is critical, otherwise keep them on a leash until they are trust worthy. They generally do well with other dogs and mine never really started fights but were more than willing to finish them.
Keep in mind the name "Bear Dog" does not equate to Romulus the Conqueror grabbing a grizzly by the neck and dragging it off of you, they don't engage like that and traditionally that was a negative response and frowned on. They circle and harrass and bark, and bark and bark. To own a KBD is to love the bark whether you like it or not cuz you will hear it, a lot. But that is what you have them for, an alarm system to let you know whats around. And don't expect them to be protective against humans like GSD's or Mals. One might be but don't expect it. They'll do a great job of letting you know when people are around but without specific k9 training they ain't "guard' dogs.
We also have a West Siberian Laika which are kissing cousins to KBD's. Very similar in many respects although I think the WSLs may have a tendency to be more aggressive than KBD's.
