I can't tell you why it fell out, but I can tell you that not having it won't affect her in the slightest, assuming there's no infection or trauma to the area.
My mum's Westie, Jack, had one of his nails removed after it was badly damaged when he was attacked by another dog. He never even noticed it was gone.
My mum's Westie, Jack, had one of his nails removed after it was badly damaged when he was attacked by another dog. He never even noticed it was gone.
