Sudden Death with My 2 yr Old Cat

Question
My catss name was Allex..he died suddenly just two days ago. I just don't understand, and he was only 2 1/2 yrs old. When I got Allex, about 6 mos after i got him, he got extremely ill...having trouble breathing, syliva dtooled from his mouth, so we rushed him to the vet..At that time..the vet really couldn't tell me what was wrong with him..only that at first he thought it was upper respirity (Pnumonia)..then after blood test (No luikemia test)...<<..He simply was not sure what caused that reaction..They kept him a couple of days, admistered aniboiots, and he came out of it. Since then, I've changed Vets, and now about 4 mos. ago, Allex started to want to have bowel movements in paticular place..(hate to say)../ like our bed or our couch.  I took him to the vet, and he said he thought it was a behavior problem.So he did no test, and just sent an antibiotic home..now 4 mos later he suddenly dies..The only simptom i can recall is mabey the day before he just wasn't responsive. He just layed on the kithen floor and dies..What kind of things can cause sudden death in cats..He had no vomiting, no diarrea..no labored breathing..Thanks

Answer
Hi Sherrie.  I'm so sorry to hear this.  I wish a leukemia test had been done, because that's one very common cause of death in young cats.  And even though the disease starts to wear them down over time, cats are so strong and hide illness so well that many times, we have no idea they're even sick.  They just die.

And leukemia very often causes lymphoma, especially in the thymus or the mediastinum.  These are located in the chest.  And the tumors can grow and grow without us ever seeing them.  My vets call these tumors silent killers, because people have no idea whatsoever their cat is sick.  Then all of a sudden, they find them dead, or they find them dying, turning blue.  By the time they get to the vet, the cat can't be saved.  I've lost a few to this type of cancer.  I literally didn't know they were sick until an hour or two before they died.

Another illness called FIP is possible.  The dry form really has no outward symptoms a lot of times.  Sometimes there's weight loss.  Sometimes it just causes organ failure, and we don't even realize it.  And the cat just dies.  But this is a somewhat rare disease and is very uncommon in adult cats.

Another possibility would be heart problems or a blood clot.  Unfortunately, heart problems are common in young cats.  And a vet may never even know about them.  If the cat is purring during his exam, the vet may miss a heart murmur.  And there's really no way to detect a blood clot, which is usually caused by a murmur.  Blood clots form in the heart, where they go unnoticed.  But when a blood clot breaks free and flows out of the heart and into the smaller blood vessels, they can get lodged and cause a stroke and instant death.  My vet told me this is almost always what happens when he sees a young, otherwise healthy cat die suddenly.  

Of course, only an autopsy could tell you for sure what happened.  I would have to say I'd seek out another vet if you get another kitty, because I'm confused as to why they didn't suggest a leukemia test.

I'm really sorry I don't have an answer for you.  That's one of the worst parts of losing a kitty, not knowing.  But know that it wasn't your fault - these things happen more often than we'd like them to.  And Allex was loved and well taken care of.