We just went through this with a jealous Westie (alpha) and new female Yorkie. I would suggest investing in some baby gates for now and limit their time together. There is no need to rush. Also your newest baby could spend some time in his crate and your oldest could sniff around and get to know him that way - safely and not stressful for you or them.
Lavish attention on your oldest so he knows he is still the top dog and has not lost his status. Very important! This helped us a lot.
Try not to intervene too much in their interactions if you can help it. Ringo would stand over top of Lucy and dominate her (growl) and she would squeal like crazy - but there was never any biting. Biting should not be allowed. Yes, when Ringo went overboard in his 'corrections' of the new pup - I did step in.
Things should get better and your oldest should settle down. Many time in the first 3 weeks I regretted my decision. We're on week 4 now and things are pretty good. Yes, there are skirmishes, mainly over food or toys) so we don't leave high value toys laying around. Feed in separate rooms.
Good Luck! Keep us posted! Your vet will probably have some good advice . . |