Dh and I fostered then adopted our lovely dogs as a bonded pair just over 10yrs ago. One is a bit older than the other.
Due to age and various health stuff (some cognitive changes, problems with vision and hearing and a cancer scare which turned out to be an abscess) we've been preparing ourselves to make the decision to pts our older dog. We keep an eye on him and he still seems to derive pleasure from walking, eating and being with us.
It came as a shock that the younger one - sweet, sharp and up to now in robust health - has multiple malignant tumours in her lungs and will have to be pts shortly. Vet has been very helpful and supportive and there's a plan in place fwiw.
Worst case scenario is that the older one won't fare well after the loss of the younger one, he's flummoxed by any change.
I'm distraught tbh. Our home is basically a dog den with beds everywhere, they're the heart of our life. Due to other responsibilities (elderly parents, work etc) the plan is no dogs for a while. I keep telling myself everything will be fine and life means change and loss.
Just wondering if others have gone through this? And 

to you if you have.