July 25, 2003
Friday - 12:05 am

Interesting question. You've decided you really like the ease of administration of the topical flea products that you put on the back of Cosmo's neck once a month, and PRESTO! he's free of fleas. But as you start perusing your pet shop's or your veterinary office's varied supply of different monthly flea treatments, your eyes start to cross.

There are a few of them, aren't there?

Let's see if I can sort them out a little, by sifting through the stuff they offer. This whole once-a-month thing started when Novartis came out with a revolutionary new product called Program©. It was a once-a-month pill that had a substance called lufenuron, which when ingested by a flea, would make it incapable of reproducing. So you gave your dog the pill, the lufenuron floated around in his bloodstream, the flea took a blood meal, and the lufenuron, in turn floated around in the fleas system, affecting chitin, the stuff that hardens the shell of the eggs the flea lays. Lufenuron kept the chitin from forming properly, so all the eggs that the flea laid into your carpeting never hatched. They just got vacuumed up and thrown out.

This was unheard of.

At that point in time, the only way to get rid of fleas on your dog was to bathe him in pyrethrin shampoos that killed all the adult fleas on him right away, and then either dip him or spray him with longer-lasting permethrins. But when I say longer-lasting, I mean you were lucky if you weren't seeing fleas again in two weeks. Or you could spray him once a day with the short-acting pyrethrin.

Summertime came, and all of a sudden owning a pet was a full-time job.

And it was even worse for cats! Because cats can't metabolize permethrins, you had to use the shorter-acting pyrthrins on Cosmo's feline buddy Harry. That was the daily one, in case you'd forgotten. Every day. All summer long.

So when a once-a-month pill came out, pet owners couldn't snatch it up fast enough. We couldn't keep it on the shelves.

But then, as always happens, we started seeing chinks in the armour.

Remember back to what started all of this flea stuff?
It was Cosmo scratching himself, and us trying to sort out what was making him itch. Now remember back to when I told you that a lot of animals are allergic to the flea's saliva, and it's the saliva that makes them itch? Well, in order for lufenuron to work, it has to be ingested by the flea. And in order for the flea to get it out of Cosmo's bloodstream, where it ends up after he swallows and digests that pill, that flea has to bite Cosmo.
And if Cosmo's allergic to Mr Flea's saliva - well, you can see this one coming - we were back to the daily spraying.

And that gets old after a while. Especially when you were all set in your mind to only have to worry about his flea thing once a month.

Next week: the next wave of flea exterminators

 
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