Should I let my dogs growl at each other?

[hedgehog]

Guinness is the old dog, a 3 year old 50 lb beagle/shepherd. Pooka is the new dog, a 1 1/2 year old 20 lb Pomeranian mix. Both are neutered males. Pooka has been with us since Sunday. Guinness came to us as a puppy and grew up under the thumb of our other dog, Jack. Jack died suddenly about 2 months ago.

So, the two dogs seem to be getting along, playing from time to time, sleeping next to each other, etc. From time to time Pooka gives a little growl that continues to barking and then Guinness starts barking back. This proceeds to snapping at each other. It stops at once if we tell them to cut it out.

I can't tell if this will go away in time or if this will escalate into real fighting. Both dogs are very well socialized and very people centered.