We never had any plans to put him through chemo. The vet said it would only shrink the tumor a small amount. Anyway, we thought about trying alkaline water, but it was too advanced. Stage 3, if I remember right.
He had about 6 or 7 weeks left to live, but the vet failed to mention that almost all of it would be spent off his feet. The morning after I posted this thread, even just trying to stand up had him yowling in pain. Even just sitting up had him panting in strained exhaustion. So we put him down later that day.
The other dogs spent the whole day pacing the house trying to make sense of his absence.