I sympathise with any one who has a nervous dog, especially when you've bred it yourself.
Milly was always a bit on the jumpy side, any sudden loud or strange noise would spook her, 2 dog dishes banging together made her squeal.Her litter brother was so different, and yet they had both been brought up exactly the same. I think that's partly the reason why I kept her out of the litter of two, thinking that a change of home, routine etc...would make her even worse.
She's always been wary of strangers, which I don't mind, as no-one could pinch her. She's very obedient, slightly submissive, b