Today we said good-bye to our big dog, Jet. He joined us about six years ago, when he was about five years old, and today we learned he was gravely ill and had grim prognosis for any treatment. It was a hard, but we hope humane, decision to let him go.
He's been a good dog. I peeked at the blog and don't see much more than an occasional mention of the dogs. 
Jet did warrant an introductory tale about a month after we got him, when he didn't quite get daylight savings. He's really been a pretty good dog since then, really the worst was occasionally getting underfoot, and knowing exactly when 5PM CDT occurred. He even went jogging with me when I tried jogging a couple years ago (and he wanted to do more since, but patiently waited until I was ready); he was pretty bad on a leash when we walked, as he liked to pull and sniff around, but he was good when he was running. He liked to chase and catch a ball, but wouldn't bring them back; we had to play fetch with a few balls at a time, 'cause he'd always drop the one he had to chase the one you threw. While originally unsure about the kiddo, he grew good at taking the hugs and the rough pettings from her.
It'd been just about a week that he had been acting a little off. He didn't want to take or chase balls, his favorite thing in the world. For the last few days he really struggled to breathe; he did best over the weekend while laying on the deck in the sun, when he got hot enough to need to pant. He had also stopped eating, including taking treats, almost for the last week. A few days ago he barfed on the stairs, but for much longer he'd been heaving like he needed to; this usually earned him a rush outside, but never resulted in more than a hacking cough. Saturday he had a bit of spontaneous bloody nose. Between Friday and Sunday he developed a huge lump on his head behind one ear. With all of this we decided it would be a good time to visit the vet.
All of the details are hazy, but the most telling were the x-rays of his chest. The vet explained that instead of the big black voids where his clear lungs should have appeared, there was a hazy, cloudy mess. The mess wasn't spotty occasional coloring that might indicate masses, but an even, thorough covering that the vet described as "intense," "complete," and "bad."
We discussed the couple of things the vet said it could be; cancer or a serious fungal infection called blastomycosis. She didn't believe there was anything else it could have been with the x-ray imaging and other symptoms.
She explained that straight-up lung cancer is rare in dogs and that usually it's the case that it has spread from other cancers; an additional x-ray would probably show another tumor. The fungus is not common, or rare, but that the severity of the lungs indicated an advanced infection.
We went for one last round of tests. They tested the lump on his head, hoping to find solid evidence of the fungus; it wasn't clear that the lump was related, but given its recent development it seemed possible to have indicators of other recent biology. They also took abdominal x-rays to try to find definitive evidence of the cancer by way of other masses. Neither came back definitive, which took away an easy decision. The x-ray did show his empty stomach, nice and clear like his lungs should have been. No masses were apparent, but the bit of his lungs that showed on that x-ray were just as bad as the others, so it removed doubt of a problem with the two previous views.
The tests that remained would be invasive, requiring a sample of the lung tissue; something they couldn't do there. They could do more blood tests, but it seems that they might not be as telling in dogs as similar tests in humans are.
We discussed some scenarios, and they all involved difficult, probably long, probably painful, and expensive treatments. Through any of it there was no certainty, and he would likely have been at least sick and uncomfortable. During the treatments he'd probably get more sick before he'd start to get better. And even in a best-case "gets all better" outcome, he'd probably not persist much longer after the treatments, given his age. More realistically, in his weakened, dehydrated state, and with the severity of the lung infiltration, the prognosis was deemed "pretty bad," and it was said aloud that he might not even survive the treatment; either treatment, for cancer or the fungus.
Without treatment he probably wouldn't have survived much longer, especially since he wasn't eating, and we couldn't start a treatment until we could be sure what the problem was. That process of further diagnosis would have been painful, expensive, and would probably have lead to a difficult and possibly painful treatment.
The vet suggested they could provide some hydration with an injection, and maybe some pain relief so we could bring him home to spend a little more time with him. Of course I wanted to bring him home, but I wanted to bring him home to be his good old self again. It is a hard thing to decide, and once we decided, I knew I didn't want to have to decide more than once; if I brought him home it would have just been harder to take him back, so we declined and made the call then.
We spent a few minutes more with him to say our farewells. He snuggled in a bit, taking the extra attention and affection. Hs tail wagged just a little, which was telling 'cause it always wagged when he got attention. He was so thin and bony, and he trembled a little bit, and worked so hard to breathe. Even those few minutes wearied him, though, and he had to lay down and focus on breathing. After a while we were collected again and called for the vet. He didn't want to go at first; I didn't want him to go, either. We put the lead on him, and he stopped by Claire for one last hug. He paused and leaned against my legs one last time and then with a final "go on" went through the door with the vet for the last time.
