[Summary: Thomas Joseph found a flea on his Husky. Now he tries to make everyone afraid of fleas.]

Yes, it happened. I found a flea on one of my dogs. I was sitting there last night at dinner, minding my own business when my Husky came over to seek attention. He's the cutest thing you'll ever see with the lightest blue eyes, and a white and copper coat that is thick and luxurious. He's digging the cooler weather so is spending most of his time outdoors. Except for dinner time. So he nudged me and I leaned over to pet him. Holding his head in my hands I looked at his face and saw a speck. I figured at first it was dirt since he loves to dig. Then the speck ... moved. My heart sunk. My pup had fleas.

Now I give all of my dogs Frontline Plus, which is supposed to do a pretty good job of keeping fleas (and to a certain degree ticks) off of them. I follow the directions closely, so I was surprised to find a flea on him. So I grabbed the pyrethrin mist, worked a few good sprays onto his face, head and the remainder of his body and then proceeded to treat the kennels with an additional spray. I'll probably have to move up my Frontline Plus application to 21 days as opposed to the 28 I routinely wait between doses if I continue to see any fleas.

Now you might be wondering why I'm relating this story to you, and have this listed under "Microbiology". I'm doing that because of this creature ...

Dipylidium caninum

I'm not a big fan of this guy, and you shouldn't be either. This tapeworm commonly infects flea-infested dogs (and cats) ... and even better, the occasional human. How? Via ingested fleas. (See CDC website)

Dipylidium caninum life cycle (CDC)

Lovely, huh? So lets start with the flea (on the dog). Dog bites areas where flea attempts to draw a bloodmeal. Dog ingests flea. Flea is dissolved, releasing cysticercoid which grow up to be a full-fledged tapeworm. This beastie, which averages 60cm in length (that's 2 feet in length for those who don't want to do the math), then starts producing proglottids which are the sexual reproduction stage of the tapeworm (in this species the proglottid has both male and female sex organs and fertilization is internal). After fertilization, you have maturation to the gravid stage.

At this point, the gravid begins the journey to the anus. It is either passed in feces, or crawls out on its own where it promptly dries up, cracks open and scatters its eggs to the environment. Along comes a flea larvae which consumes the egg. Oncospheres hatch from the egg, make their way out of the intestinal wall, and form cysticercoids by the time the flea matures to its own adult stage.

So, not to sound the alarm but if your dog (or cat) has fleas, you really want to treat them as immediately as you can. Small children, who are prone to putting things in their mouths, can easily ingest a flea causing them to become infected. It can also happen to adults as well, and while rare, I wouldn't consider it something to be ashamed of. So what if  you have a two foot long parasite in your intestine, from which tiny moving critters detach and crawl out of your anus? No biggie.

And it really is no biggie. A single pill will fix that right up for both you and your pet. For your pooch, the vet can give you Droncit, which is also what your doctor will prescribe to you under the generic name of praziquantel. How will you know you (or your child) has it? Sometimes you'll experience stomach pain and bout of diarrhea, but oftentimes unless you see the gravid stage in your shorts you may never know.

But like I said, its rare. You're more likely to get tapeworms from raw fish (read: sushi) but I wouldn't want to alarm people by writing about those. Bon appetit!