Case: 8 year old English Setter. Beloved dog, and close companion of my disabled wife. Impossible dog to replace. Dead in two days from apparent liver disease.
Rather than make this just another sob story, I need to pass along some things I learned. Be on the lookout as your dog ages, as it turns out I had ample warning and misinterpreted what I was observing.
Dog was slowing down a bit. Nothing dramatic, but activity level definitely dropping. Put on some weight, but it's winter here and it's normal to slow down a bit. He started pressing his head on my chest... I saw this as a sign of affection. He started snoring louder, which I put down as an after effect of his slight weight gain. Resolved to start taking walks when I returned from a week long trip.
He didn't last that long. Without getting into specific details, it turns out that 'head pressing' can be a sign of encephalitis, in this case caused by liver failure. The change in breathing sound undoubtedly was because of an enlarged liver.
If I had it to do over again, I would make routine blood analysis part of his annual check. This might find elevated liver enzymes. I did this with a previous dog on the recommendation of his vet, but simply forgot to ask about it with this guy and it wasn't offered without asking here at my new home. This may not have been much help, especially if this was a case of cancer, but at least we would of had some warning.
Observe behavior changes in your dogs, and don't assume something is minor. Use available diagnostics routinely.
We miss the hell out of that dog, and the possibility that I failed him will linger forever. Be smarter than I was.
