Spoke with DM last night in UK. I live in Asia.
They have a 12 yr old black and white springer spaniel. She is the most divine creature. I really, really love her. She is a super dog.
DM and DF have planned a week away for a year. It's a big deal and they are unlikely to cancel it.
DDog is going down hill and DM is taking her to the vet today (Tuesday) to see how long he/she reckons she's got.
They feel she is too poorly to go to the person who will be looking after her and other DDog.
She is almost deaf, quite blind and her back legs are going a bit. She sleeps a lot, but she's still wagging her tail.
I am terrified DM is going to have her put down when she could still have a bit of time left. And as my family and I arrive in the UK for the whole summer this weekend, I was going to collect the dogs as we arrive home before DM and DF get back. Selfishly I want to collect 2 dogs, not 1.
I know she belongs to my parents, but I am gutted they may not keep her around for the last few days til I get home and then we can make the decision together. I REALLY want to be home for that, not 4000 miles away. I also do not want to hear my mum blame my dad for putting pressure on her to do this so they could go away, I have a feeling I will never hear the end of it.
FWIW I had to have our own family DDog put down 18 months ago, so I do understand about quality of life. I spoke about that on this board, under a different username (had to change due to email thingy).
I guess it's just supremely bad timing isn't it? Poorly dog, week away and our homecoming all within days...
I will speak to DM later today. I am just looking for some hands to hold. I absolutely HATE being so far away when this sort of thing happens.
And thanks for letting me vent a bit. 
Here is a photo of her at Easter. (she's camera shy).
xxxx