Yorkie keeps snapping, biting, growling, barking.

[SimplySteveRedux]

Yorkie, about 13 now, keeps snapping and growling at me and DP, and wages all out war against our other dog (Shih Tzu). He also barks at all hours and we simply cannot curb any of his behaviour.

We're in the process of moving home and DP is refusing to let him go. He's always had a nasty streak (had him since a puppy), we've tried anti-bark collars etc for the barking with no effect.

Frankly I'm fed up of the constant aggression and nips/bites.

Any advice?

Trip to the vet and a muzzle.

What would a vet be likely to do?

Yes first port of call is take him to the vet to make sure there's no health issues. He could perhaps be in pain? He is 13 and might have sore joints or may be something internal.
Although you say he's always been like this. Has he gotten worse recently?

See a vet in case a medical condition is causing pain and/or grumpiness

Keep him separated from the other dog. It's not fair to them both to have them in any situation where the yorkie can wage war.

Look at ways he might be stressed and how you can reduce that. Moving home can be very stressful for dogs and makes behaviour like barking worse because they are less able to tolerate the little things. A bit like a human who gets more shouty when things are not going well at work.

What have you done to stop the behaviour?

Has the dog seen vet in case he's in pain or confused with something like doggy dementia?

What's happening when the dog nips and snaps? They won't do it without a reason - it could be pain, fear or disliking what's happening to them at the time.