Danielle,
I hope today brings you some peace with your Abbi, and your thoughts.
After having to make the decision for a couple of chooks, cats and a heartdog in recent years, and in different circumstances, I think the best advice was given by NotSureWhich - Better a day too early than a minute too late.
To be able to make the decision for one so loved is both an honor and a curse, but it is one we take on as pet owners.
Be guided by your girl and by the vets, and know that she will thank you for letting her run free again at rainbow bridge when the time is right.
shena
