Just a heads up, this year in Northeast Kansas we have been diagnosing several cats with Cytauxzoon felis. This is a tick born blood parasite that is almost always fatal in cats. Bobcats serve as a reservoir host that remain asymptomatic long term. Ticks feed on infected bobcats and then fall off and possibly then feed on domestic cats if the opportunity presents itself. This blood parasite infects red blood cells and macrophages causing anemia and damage to spleen and liver. Once clinical signs of lethargy and anorexia occur death usually occurs in less than a week. Not all topical tick medications work 100% so the best prevention is to keep your cats indoors during peak tick times. If that isn't an option do a tick check every evening at feeding time. It's one of those crappy diseases that happen to great cats and our recommendation is euthanasia if we diagnose it.

Thank you for posting this.

One of our cats just died about half an hour ago and I wonder if this is what she had. She was a quite healthy outdoor cat, 4 years old.

Yesterday she was normal, even jumped into my lap outside for her daily petting. This evening I found her in the garage next to the chair we usually sit in, extremely lethargic so I brought her in the house and the kids and I put her on a towel on a bed. She "perked up" a bit for an hour or two, then started spasming and died.

Since she had been appearing in good health, I was wondering if she had been bitten by something venomous as at first she had trouble mewing but it appeared to have been improving until everything crashed over the course of 30-40 minutes. I had a girlfriends cat who got feline leukemia once and had similar spasms before it died, but that disease was a lot more drawn out than this was, about 24 hours from a daily cuddly snuggly pal to passing away.

Mark...did she by any chance have asthma?

Although the asthma itself is not usually fatal like that, untreated it can lead to congestive heart failure.

The last cat I saw die from congestive heart failure went from being happy as a lark all day 'til suddenly that evening she had exactly the symptoms you describe and died within half an hour.

Alberta Canuck,

No she did not have really any sort of respiratory illnesses pretty much ever. Also, I was listening to her lungs when she was sick and did not hear any of the wheezing or bubbling that accompanies CHF.

Since then, the only two other possibilities I can see are either she was bitten by a snake or got poisoned by something.