Expert: Jessica - 7/23/2009

Question
QUESTION: Jessica,
Saw an answer you gave on roundworms from 2008 that was more comprehensive than any one article I've seen from hours of online research!

We're fostering two kittens from a shelter that were diagnosed with roundworms and immediate treatment with Pyrantel was administered.  They will each receive another dose of the medication two weeks after the first dose.  Unfortunately, I didn't realize just how resilient the eggs were until I did research (and after they were home for a few days), and when I speak to various vets or vet techs, I get repeated conflicting (and sometimes just darned wrong!) info on hygiene.  I realize the eggs are nearly impossible to get rid of entirely once in an environment, but proper hygiene (wash your hands before you eat!) seems to be best advice after you've done everything else possible.  But my main question:  After treatment with Pyrantel has begun, how long until the cats are no longer passing any more roundworm eggs in their feces?  I've only found one reference that said two days after starting treatment for DOGS, but my vet's office (tech) said keep up strict hygiene for two weeks.  

What say you?

Thanks so much!

ANSWER: Hi Carol.  I certainly understand the paranoia that's spread out there!  These things can be murder to get rid of.

The real answer to the question is that adult worms are displaced beginning within just a couple of hours of dosing, with the roundworm infection gone within 1-2 days.  No further egg laying takes place after this.  Although eggs are free-floating in the intestines and could potentially linger behind their "now in a better place" parents, two days is generally ample time for egg shedding to end.  

During this time, I always recommend using a disposable litter box, so you toss out the litter and any eggs that were passed in the kittens' feces with it, before they become infective.


---------- FOLLOW-UP ----------

QUESTION: Jessica,
A second dose of Pyrantel will be administered exactly 14 days after the first treatment to get rid of any further developing roundworms.  Will any of these newly developed roundworms produce eggs during any part of this 14 day period, or are they still immature enough that they will NOT produce any eggs so I don't have to worry about "super squeaky clean" hygiene during this time period or the two days after the second Pyrantel dose?  Thanks.

Answer
Hello again!  Hope things are getting under control.  It takes three weeks for newly hatched larvae to develop into fully mature, reproducing adults.  So by repeating treatments two weeks apart, you should, indeed, kill any worms before they have a chance to produce any eggs.