jealous new dog

Did you introduce them immediately or gradually? Normally you'd want to put the new dog in a bathroom or some closed room (with food and water of course) and let the old dog get used to the new dog's smell without seeing it. A day or two later you'd introduce them at feeding in the same room but with separate bowls.

If you didn't do that the dog may feel like his territory is compromised, and it's normal for him to lash out.

Try to go out of your way to treat both of them to special things together. Feed them together, give them treats together, walk them together. And also go out of your way to spend more time with your first dog so that he doesn't feel like the new dog is taking away his attention.

Thank you so much for your response Robert. At first they were introduced straight away so you may be right. they now have separate bowls becouse Ivor ,my new dog, didn't like my old dog near it and thats getting much better now. I can tell already that Ivor is going to be the dominant of the two, so your right maybe Ivor feels that my old dog, Indy, is overstepping his mark.
I appresiate your advice, thank you.
mich

Different food bowls is a good idea, that can be a primal thing for animals. I've seen dogs get along great till they have to share food. Anything else you can do to put them on equal footing will help. Dogs have been shown in studies to understand differences in treatment very well. Have a look at this article about a study showing dogs were much less likely to obey if they felt they were getting inferior treatment to another dog:

http://www.wired.com/wiredscience/2008/12/dogenvy/

There is also a primate study along the same lines that was interesting, the primates were first both given cucumbers, which they liked. But when one was given grapes (which they like a lot more) the one given cucumbers became sullen.

Try not to give either dog too much attention alone, and try to make their rewards (walks, treats, food, petting etc) shared as much as you can.