It is possible the eye is damaged from a bite around the eye area slightly popping the eye forward. This can break a blood vessel or do other damange.

This is a common injury in breeds of dogs with bulgy eyes. When the other dog goes for a cheek grab the eye is in the way and can get injured. You can try a cold damp facecloth (not ice) over the eye for 5-10 minutes for pain and swelling. Just refresh the facecloth with cold water as it warms.

She was likely shivering due to pain and fright from the attack.

The swelling under the chin can be from a puncture above that area or a grab that did some crush injuries. Dog bites work two ways. The teeth pop through the skin and then do damage under the skin so you only see a small puncture but a lot of bacteria is left under the skin area. Next the less sharp teeth do a lot of crushing mashing the tissue around under the skin breaking small blood vessels and causing bruising and swelling.

The swelling is likely from that under the chin area and elsewhere.

Keeping her quiet is good until you can see the vet for evaluation.

If the rat terrier is not spayed then this may all be due to the pups growing up and maybe the terrier coming in heat.

The way it works with dogs is pups are alllowed a lot of leeway but as they grow up the adults can get a lot rougher with them if they don't follow dog rules. Plus if there are any hormones involved rivalry can get a lot stronger.

This could have started as a squabble over a toy, chew treat, food etc.

I'd plan on figuring out the next steps of what you will need to do to keep all dogs safe. You may want your vet to refer you to a local trainer or a veterinary behaviorist.

Or you can check www.apdt.com for trainers near you looking for one to help you resolve this i fy ou can.

Hope this helps you!

You do need vet care to determine how bad damage is, if you need meds to control swelling or infection, if a drain needs to be put in, how she is going to do etc. Depending on how bad eye damage is she might need the eye removed but hopefully not.

No I do not think this was a one time event with the dogs fighting, though Merlot may be submissive/scared enough from now on to stay out of the other dog's way but that doesn't always mean the other dog will back off. Female on female fighting is the worst usually to cope with.

Because it happened when you were not home I'd keep the pugs and rat terrier apart when no one is there to supervise them. A baby gate or two might work for that.