> I would go for an extended course of ABs, could be that as it is not normal to scan a bitch shortly after her season that the time taken for the cervix to close may differ from bitch to bitch
My old one has this due to her age, i keep AB's ready to prevent infection when she has a season. The vet said the cervix is open so able to let muck in if the dog is able to clean it properly or get down properly, as in my girls case. She'll be fine and will sort itself out. Nova is right about the AB's. i just let my vet know i need them.
She's only had the odd water infection from this, never a womb infection. Personally I wouldn't consider speying, but that's me.
I agree with everyone else, change vets and ask them for a refund. They put you through unnecessary worry and possibly an operation. How they confused that with a mass is beyond me. Glad she's ok.