We have a puppy/dog that is about 17 months old. He’s medium build (about 70 lbs) lab/shepherd mix. Over the last few days, we’ve noticed he is hesitant to sit and will go right to laying down. He CAN sit, but when he does his leg/knee will be placed further out to the side versus tucked under him like the other side. He runs and walks normally. We have an appointment with the vet next week. Any guesses what this might be? He’s our first fur baby.