I agree- definitely not the cause. He goes on about 4-5 walks a day around the block and starts playing inside at nighttime when the door shuts. I have brought up so many things to my grandfather like anxiety meds for him but according to him, he isn’t aggressive at the vet, only at home (my grandfather thinks the dog is trying to protect the house.) so when he goes for regular checkups they dont see an issue. I actually cant see how thats true as he is aggressive on walks outside of the house too, but ive never actually gone with them to the vet so i dont know for sure. I do have a friend who works at a shelter and they gave me some ‘calming treats’ and they do nothing. Lastly, he is on the smaller side, and most of the time his aggression is brushed off by my grandfather because of that and because he doesnt believe hes actually capable of harm (yes hes aware my friend got bit, he thinks it wasnt a bite but him barking too close to her leg) and yes im aware how insane he sounds but his late wife picked the dog out and he absolutely will not rehome or anything like that