Our border terrier was at the dog groomers today and when we went to pick her up the lady told us that our dog's nipples were leaking milk and it was likely she was going through a phantom pregnancy.
We have noticed no difference in her behaviour at all and if it hadn't been for the dog groomer we would probably have never known. She was last in season approx 3 months ago.

What causes a Phantom Pregnancy and do we need to do anything?

>What causes a Phantom Pregnancy and do we need to do anything?

Phantom pregnancy to a greater or lesser degree is normal for bitches after every season. Some will show very minor symptoms, just being a bit moody; others will produce milk, and others will gather together toys as pretend puppies and guard them.

You need to reduce the protein level in her food and give her plenty of exercise, not allowing her time to brood and get emotional - a bit like your old games mistress at school!