Straight away and as soon as possible this dog needs to go to the vet!!

Explain the sudden change in behaviour, when you noticed it, what the dog was like before and how quickly things have changed.

Tell the vet (and us if the vet checks out OK) how long you have had each dog, what sex and how old each dog is, if the dogs have been neutered and anything that has changed in the past few weeks....have you had a baby, moved house, changed jobs..... anything?

If the vet check is OK let us know and if not let us know. You make it sound like a sudden thing and the vet will need as much information as you can give.

Please let us know what the vet says.