Just thought I would post an update on the situation with Coco and the barking! It is now 9 months since the alpacas arrived and things are much better although we are not quite there yet. After all the stories and advice on here, I did not use any aversives in the end even though she was driving me to distraction

She has gradually learned to tolerate being in the garden while I am in the field for short periods although if she thinks I am taking too long or if anyone is out there with me she will still go barmy.

The biggest improvement though has been in her behaviour with the alpacas and when she is in the field. She is whistle trained so I took her out and walked around the alpacas on the lead for a while then let her off and keeping her focussed on me with a tasty treat got her to recall to me. Started some way away from the alpacas and gradually increased the distance so that eventually the alpacas were actually between her and me - recalled her from there meaning she had to run past them without chasing or barking at them. She has done really well and although she will occasionally still have a bit of a chase, it is more half hearted and she usually stops when I tell her no.

It has improved things no end because it means that most of the time when I am out in the field poo picking etc she can be out there too although now the chickens are out there too, I have to make sure she cannot get at their food - bizarrely she doesn't show much interest in chasing them

What sort of a gundog is she anyway?
