Wednesday, November 26, 2014

I have worms


City Slicker:  "Boy, your dog is some special kind of ugly!"
  Country boy:  "Yep.  He shore is."
City Slicker: "Can he hunt?"
  Country boy. "Nope.  He don't hunt."
City Slicker: "Is he a good watchdog?"
  Country boy: "Nope.  He just sleeps all the time."
City Slicker: "Is he a fighting dog?"
  Country boy: "Nope."
City Slicker: "He does not even look healthy."
  Country boy: "He's got worms."
City Slicker: "Why in tarnation do you keep that worthless thing?"
  County boy: "Well, I do love fishing and I never have to dig bait."

Picture from HERE
I did a little research and determined that our Boston Terrier is afflicted with tapeworms.  The medications used for round worms are not effective on tapeworms.

The drug of choice to control tapeworms is Praziquantel at 5mg-to-10mg per kg of body weight.  It is given as a single dose and no special feeding regime is required. It has a fairly wide therapeutic window. The lowest cost option of treating all three dogs with Praziquantel (80kg at 10mg/kg) will be in the neighborhood of $35.

Fenbendazole is the second choice.  It requires 50mg/kg, applied three days in a row.  Fenbendazole is widely available and is economical in horse and cattle formulations, the  most common dilution is 100mg/gram of product.  The primary advantage of this product, for me, is its availability.  The lowest cost option for treating all three of my dogs with fenbendazole is approximately $20.  They take liquid meds well when mixed with shredded cheese.

Vets get nervous when patients go "off label" and use products intended for other species.  The biggest concern is that most people are incapable of math.  

A related concern is that specific species (and the target pathogen) can have wildly differing dosages.  As a very general rule, species that are herbivores or scavengers can tolerate higher dosages and have shorter elimination half-lives than carnivores.  The usual explanation is that herbivores have greater "gut-fill" due to the lower energy density of their food, plus evolution demanded that they have ways of excreting or otherwise tolerating phyto-toxins  Scavengers needed mechanisms to excrete or detoxify myco and bacterial toxins.  Ominvores typically fall between scavengers and and carnivores.

An example is ivermectrin dosing. An 80 pound ewe would be dosed with 9 cc of 0.08% pre-mix.  The dosage for an 80 pound dog (for heartworms) would be 0.3cc, or 1/30th of the sheep dosage.  And this much, much lower dosage can still be fatal for certain breeds of dogs.

Preventative measures


Tapeworms can be spread by fleas so a key part of tapeworm control is flea control.  Winter is a great time to knock back the flea population.  There are countless products that can be fed to the dogs, squeezed across their backs or put around their necks.  The other half of the control program involves sanitizing the environment: dog bedding, carpets, furniture and so on.


Business opportunity


Mrs ERJ has vetoed many of my business schemes.  Given high school and college girls' unquenchable desire to have concave tummies, I proposed selling tapeworm segments on eBay...for scientific purposes, of course.  I figured it was no grosser than "colonics", that is, recreational enemas.  For some reason Mrs ERJ does not want me vermi-farming tapeworms for the flat-tummy market.  Bummer.  

Never one to begrudge anybody a promising business idea, I will gladly send seed-stock to any of my loyal readers...for a price, of course.


3 comments:

  1. This comment came in by email from a Vet in Kentucky:

    "Joe,

    Playing the odds…your Boston Terrier probably has Dipylidium caninum, the common ‘flea tapeworm’. Probably the most common one most pet-owners will encounter.

    Taenia spp. tapes, which dogs get from consuming rabbits & other small game infected with the larval stages, are even cheaper to get rid of (if the old ‘rubber football’ d-toluene wormer capsules (Happy Jack was one I remember from back in the day) are still on the market…

    For those ‘tapeworm capsules’ to be effective, they’d have to contain the larval stage (cysticercus) of Taenia saginata, the human tapeworm – which would come from ‘measly beef’, condemned at a slaughterhouse (I’ve never even seen it in person).

    Gotta be careful though…if you got Taenia cellulosae – from ‘measly pork’, you’d also end up with the adult tapeworm in the GI tract of humans who consumed it – but unfortunately, humans can also serve as the intermediate host, so if they didn’t practice good personal hygiene – like washing hands after going to the bathroom, they could end up with neural or ocular cysticercosis, a very bad deal.

    Attaching an old article that I usually distribute to my parasitology students….

    Happy Thanksgiving... "

    And a scan of this article was attached: http://www.ncbi.nlm.nih.gov/pubmed/473521

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  2. Another update appeared by email:

    "Oops. Got my scientific names mixed up in that last email.

    The adult human/pork tapeworm is Taenia solium. The larval stage, present in the pork, is Cysticercus cellulosae.

    If you (generic), ingested those Dipylidium tapeworm segments from the dog feces, nothing would happen – but if you happened to consume one or more fleas, containing the cysticercoid(larval) stage, then you could develop tapeworms – and D. caninum has been reported in humans – usually kids(linoleum lizards, carpet crawlers) who accidentally ingest flea larvae/pupae as they crawl or play around on the floor/carpet.

    Maybe Mrs. ERJ wouldn’t be so opposed to you capturing the fleas and selling them?

    Tapeworms are among my favorite parasites (is that weird?). Somebody WAY smarter than me had to figure out those life cycles…who’da thunk that tiny little cyst-like structure in the muscle tissue or liver of that cow or squirrel would become the adult tapeworm that we all know and love? ;>). And who identified that tiny little cysticercoid larva in the tissues of the flea or free-living oribatid mite out in the pasture, and made the connection to the tapeworm in the dog or cow/sheep/goat?"

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  3. I bet I can name in one guess who emailed you that comment! lol

    I recently saw a segment on Untold Stories of the ER in which a teenage girl had an impacted bowel from tapeworms, she had taken a "capsule of tapeworm eggs) sold in Mexico. For weight lost purposes.

    ICK

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