Thursday, March 15, 2007

Heartworm Survivor

Well, short of doing a $1000 ultrasound we cannot be certain, but the passage of time has made it essentially certain that Molly is out of danger. (The ultrasound would also require shaving her tummy, and that is just pathetic.)

We adopted Molly a bit over two years ago and found out shortly afterward that she had heartworm. We promptly went on the Internet and found out more about that issue that we really wanted to know, part of which I’m going to share with you. Molly is not big, she weighs less than eight pounds, so a spaghetti-sized worm (or up to, perhaps, three of them) living inside a chamber of her heart is not a trivial issue.

It had been thought for a long time that cats don’t get heartworm, but recent studies have found out that they do. The parasite reacts very differently in cats that in dogs, however, and for a rather interesting reason. First a simplified version about the life cycle of the worm, which is actually rather interesting.

The worm lives in a chamber of the heart of the host, not in tissue, but in one of the chambers, attaching itself to the wall thereof similarly to the way a tapeworm does in the intestinal tract. It is, as mentioned previously, about the size of a piece of spaghetti and can be up to a foot long. It lays eggs in the bloodstream, but those eggs do not hatch until they are slurped up by a mosquito, where they turn into larvae. When the larvae are injected by the mosquito into another host they turn into another worm and it begins again.

The interesting thing is that cats have a very powerful immune system that kills most of the larvae. So where a dog may have thirty or more worms that, if not treated, will result in death to the dog, a cat will usually have only one or two worms and pretty much no symptoms at all while the worm is alive. Which is fortunate because the medication that you can give to dogs to kill the worms cannot be given to a cat because the medication itself usually kills the cat.

The only feline symptom that is common while the worm is alive is that the cat may be “averse to exercise.” Yeah, right. Exactly how does one tell when a cat is displaying signs of being “averse to exercise” anyway? It sleeps a lot? A bag of cement is also “averse to exercise.”

The cat may also throw up sometimes, although perfectly healthy cats do that too, apparently for no other reason than to piss off those who have to clean up after them. There can also be some lung inflammation, and Molly did have a coughing problem which cleared up after a brief course of Prednizone.

Anyway, the worm lives in the cat for one to two years and real danger comes when the worm dies. It loses its attachment to the heart and is injected into the cat’s lung where one of three things can happen: a) pretty much nothing, b) serious breathing difficulty requiring hospital support but eventual recovery, or c) very sudden death. Scary.

At her annual exam this week the vet said that Molly was looking fine and that we could rest pretty easy on the heartworm issue. Another year, she said, would put it to rest for sure, but she felt the issue was pretty much done with at this point.

The bottom line here is that Molly is small but seems to be a pretty tough little cookie. She’s kind of cute, too.

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