Well, yesterday our cat Evinrude had to be put to sleep.
Long story short, he had been acting sickly on Tuesday but we though he was constipated or had a hairball, as he sometimes did, so we gave him the appropriate treatment for that.
On Wednesday he got steadily worse and started to get very cold and lethargic.
When we got him to the vet they told us his urethra was blocked and that his bladder was so full the toxins had spread and his kidneys had already started to fail.
Even if the had the $1400 or so for his treatment he likely wouldn;t survive or would have a dreadful quality of life.
We made the horrible decision to have him put to sleep and were with him when it happened.

The lesson to learn from this;
If your cat suffers from urinary tract infections feed them the appropriate special food for the rest of their life with NO EXCEPTIONS. It's expensive, but it's worth it.
We thought we couldn't stretch our tight budget and fed him regular cat food. Now I wish we had sold something to buy a year's supply. It would have saved his life.

Here are a few pictures of Evinrude. He was a wonderful cat and he was dearly loved and will be dearly missed.