Hello! We adopted a male great pyr not knowing at the time he was a pyr (we thought he was a lab mix). I'll try to make a long story short about how we came to have our pyr (Hank). We foster for a beagle rescue and in Aug fostered a mom beagle with 2 beagle puppies who were pulled from a shelter in Kentucky. The shelter had a random white puppy turn up alone who was only a few days old (eyes still closed) and stuck him in with the beagle mom as she had started to nurse him. So we have had Hank (the white puppy who turned out to be 75% pyr 25% husky) since he was tiny. He was raised with a beagle mom and two beagle siblings (who have since been adopted out) and has never been around other pyrs. Anyhow, the reason for the post is that obviously nothing about his behavior turned out to be "lab like". He has done ok with basic training but definitely is stubborn. It's like he just doesn't care at all what I want him to do and he has no drive to please unless I have particularly tasty treats. He knows what I'm asking, but just looks at me like "eh not now". While taking him to puppy socialization and training class it was suggested he may be a pyrenees, which we confirmed with a DNA test. Now having found this out, and reading more about the breed, his personality makes more sense. I have accepted that our Hank will be nothing like our beloved lab mix Booga (who passed away the previous summer), and I definitely love Hank to pieces. I can deal with him smacking me in the face with his paw and being stubborn (having beagles independent/ornery dogs are nothing new). What I worry about is him being aggressive, especially with how big he is already. On my pyr research it seems that this breed can be very dog aggressive and even reactive with unknown people. His puppy training class is over and he did fine with the other puppies there, though he did seem less playful than most of them. We walk him but being the winter months there aren't a ton of people out. What is the best way to prevent aggression? We've tried to ramp up his socialization and he has done well with everyone he's met other than some puppy mouthyness. Is it typically only with other large dogs that male pyrs are aggressive and dominant? Or other large dogs? We have a 9 y/o female beagle and a cat and I worry if Hank ever did become aggressive with them they'd have no chance. At 15 weeks he's already 15-20 lbs heavier than our beagle Lila. So far they have played fine and they have bones ect. without any food or resource guarding but based on what I've read it's when pyrs are 1-2 years old they start having issues. Do any experienced Pyr owners have any suggestions on how to prevent a pyr from being protective/aggressive? Or any signs to watch out for with him? Thanks in advance for any help!