My 6 week old Tibetan Spaniel puppies playing in the kitchen! Don't forget to thumbs up, favourite, and subscribe for more! My Website: www.baradkennel...
Sorry to hear about that. Aggression within the pack is one of the more difficult behaviors to find the root cause of and apply an effective, gentle modification for. While it may not be addressed specifically, I would suggest viewing, "Martin McKenna, the Dog Whisperer". He has a channel here on RU-vid. These Tibbies are very dog smart, therefore they can be manipulated if you know how. As per Martin, "Chin up!".
There's a genetic thing among Lhasa apsos and i think Shih Tzu also, where due to them coming from common ancestors or long ago interbreeding with Tibbies, the other two breeds will occasionally produce puppies with a very Tibbie-like coat and size. These breeds are pretty similar aside from those factors. You might have one of those dogs, and it could still be totally purebred Shih Tzu.