Worm Pills

If someone asked you for a worm pill, what would you give them?   Sometimes I think of a little shop in Diagon Alley [if you’re not a Harry Potter fan, ask someone who is] and a wizened little old man pulls open a number of ancient wooden drawers.  The first pill he hands you has a worm in it. You take it so that you will then have a worm inside you, like a bottle of tequila.  The second container he hands you appears to be empty at first.  The pills inside it are very tiny so that they will fit into a worm’s tiny mouth.  Then he hands you a pill shaped like a worm (though I suppose this would be more of a lozenge than a pill).  Then you slap me and tell me to get to the point.  Good thinking.

Today, class, we confine our discussion to the treatment of intestinal parasites (by which I mean that we will not be addressing the heartworm situation).  It is a fact that dogs and cats (and most other animals, as well) can be afflicted with a number of little creatures that live in their intestines (and eat them, or at least, eat their food).  The less particular you are about what you eat and how it is prepared, the more likely you are to fall victim to this sort of thing.  The little boogers live in the intestinal tract and their eggs pass out the other end, contaminating the soil.  Your pet can pick up the infestation from the soil, or from intermediate hosts that have contacted the soil.  Don’t eat dirt, raw meat (even if you just killed that rabbit yourself), or cat poop.

Most commonly, you could have nematodes (round worms) or cestodes (flat worms) or filaroid worms (tiny, thread-like worms) or protozoa (microscopic, one-celled animals, like "Montezuma’s Revenge").  Hookworms, whipworms, and roundworms (ascarids) are the most common nematodes.  Tapeworms of several species are the cestodes.  Coccidia and Giardia are protozoa.  While there are many other possible offenders, these are the usual suspects where I practice.

I have taken pains to separate them into different biological families to help you remember that there is no one medication that is going to clear all of them from an animal’s digestive tract.  If we see symptoms of intestinal parasitism, we need to identify the parasite in order to eliminate it.  You have to use the correct medicine on the correct schedule.  With some parasites, you may also have to take extraordinary sanitation measures.  This is why the purchase of a "worm pill" is far from guaranteed to give the desired result: a pet who is free of parasites.

Roundworms and tapeworms mostly just eat the pet’s food as it goes by, depriving the pet of that nutrition.  Hookworms and whipworms are blood-suckers;  they also damage the intestinal lining in the process, making digestion less efficient.  Giardia and coccidia damage the bowel lining so that it cannot properly absorb the nutrients.  All have the effect of depriving the animal of his full nutrition, thereby creating an unthrifty state, plus or minus diarrhea, plus or minus blood.  You get anything from just having to eat a bit more, to being rather thin and scruffy-looking, to having severe diarrhea, to actually being exsanguinated (having all your blood sucked out; I could have just said that, but I do love the word exsanguinated).

One day you see your pet having some degree of the above symptoms and your Uncle Bob says, "I’ll bet he’s got worms."  Well, Uncle Bob never steered you wrong before (except for that licking the flagpole thing), so you know you need a worm pill.  [No, you need a DE-worming pill, or vermifuge, as we scientists like to say.]  Off you go to Wal-Mart or the feed store (see yesterday’s post).  Most of what you will find will be either piperazine (which only kills roundworms) or pyrantel (which kills hookworms and roundworms, the two most common parasites).  Both of these drugs are pretty safe.  Notice that neither of them affects whipworms, tapeworms, giardia or coccidia.  Also, the packaging isn’t going to mention that.  It also isn’t going to mention that the only way to find out which parasite you’ve got is to examine the poop under the microscope, looking for egg stages (and a few other things).  Nine times out of ten, you’re not actually going to be seeing any worms pass out.  Puppies sometimes pass or vomit up roundworms and quarter-inch segments of tapeworms pass, which are big enough to see.  The rest of them stay in there and eat your pet, or are microscopic and you couldn’t see a thousand of them holding hands (or cilia or whatever) if they did pass. 

This means there is a good chance that you’ve purchased a medication that is not effective against the problem your pet has.  Even if you lucked out on that, it requires different follow-up schedules of treatment to be effective.  That won’t be on the package either.   Hookworms three times, two weeks apart.  Whipworms three times, four weeks apart.  Roundworms two times, three weeks apart.  Giardia twice a day for five days, coccidia once a day for ten to fourteen days.  AND SO ON…

Or you could get unlucky and find a store that’s carrying weird crap like arecoline (see yesterday’s post) or N-butyl chloride, or methyl-benzene.  These are chemicals that went out of style fifty years ago as soon as we got something better.  They are somewhat toxic.  You can’t give them safely to sick or debilitated individuals (say, someone who is really wormy).  For instance, methyl-benzene is also known as toluene.  Does that name sound familiar?   Did you ever build model airplanes as a kid?  Remember Testor’s Model Cement?  Yes, toluene is the active chemical solvent ingredient in AIRPLANE GLUE.  Put it in a gelatin capsule, and hey, presto! It’s a "worm pill".  Don’t huff it, give it to your puppy…NOT!

This is what you need to do:  collect about a teaspoon of a fresh poop (less than 12 hours old) and deliver that to your veterinarian, along with your pet.  He or she will analyze the specimen, do a microscopic exam, detect and identify the parasites, and prescribe a safe and effective medicine on a schedule that will free your pet from his parasites.  It’s so simple, but it does involve more than a "worm pill".