Some pups will have the ear flop one day and then be erect again within a few days. However, usually by 6 months the ears have decided what they are going to do and usually end up staying the way that they are. If you are set on having erect ears you can tape a pup's ears to help them to stand up.

At what age do cairn terriers ears stand up?

All puppies are born with their ears flat against their head. Between 4 and 7 months of age, if your puppy is meant to have prick ears, they will usually stick up. It can take up to a year for a puppy's ears to stand. Some puppy's ears stay floppy forever, even if prick ears are characteristic of their breed.

Do cairn terriers ears go up?

Cairns do not have floppy ears; the ears should stand erect, although there will be the occasional cairn where one or both ears are folded over.