You are so right - it's extremely difficult so unfair because she is so young. I have no worries that you will do right by her though. You really will know when it's time. Animals and people both know when the time is right, and it's really obvious when it comes. You're doing everything just right, and your dog is very lucky to have such a wonderful owner. :-)
The most difficult thing is that she is able to run on adrenaline when she is excited -- like when she sees my boyfriend or my dad -- she almost seems completely normal. And so we get that "spark" back a little bit. But then she crashes and comes home and throws up.
I know what the right thing is. It's just hard. And unfair for her age.
Thanks,
Kate
Sadly, I agree with becks. Think of 3 things that your dog just loves so much that makes her "her". Once those 3 things are gone, it's time. I would at least keep her on a low dose of pain medication until you come to your decision. Dogs are pretty stoic when it comes to pain, and you obviously don't want her suffering. They just don't complain the same way that people do. Better to have her spacey than hurting. Really sorry to hear that such a young dog is so sick. :-(
It's time when they cannot live a normal life - you said it yourself she isn't the happy daisy anymore - she has to be on meds all the time to control the pain and symptoms, she doesn't want to eat much... I think you need to come to the realization that it's time to let her go.
Cancer is a horrible thing in humans or animals and I think being able to put her down is a blessing - she can go peacefully and before it gets too bad. She doesn't want to be dependent on you to lift her on the couch and probably other places in time. That's not a good life. I wouldn't want that if it were me.
I feel for you - she is still so young and I get that it's hard. Do the kind thing :) It's not fair to her to keep her around if there is nothing you can do to heal her. Big hug to you in this difficult time.