Expert: Jessica - 1/16/2012

Question
Hi there,
I have just rescued a 8 lb. 3 year old cat from the Humane Society.  From day one Luna had diarrhea, and after a trip to the vet she was on a 10 day dose of metrondazole (0.6ml 2 times/day) and put on Med-ical's GI High Energy food.  This did little to help, so we took her in for a 2nd visit 7 days later where the vet upped her dose to 1ml 2 times/day, changed her food to the Med-ical GI high fibre, and sent out a sample of her feces.  A few days later they told me she had roundworm,so we dewormed her with Milbemax (16mg milbemycin, 40mg praziquantel) & instruction to repeat in 14 days.  She did pass one worm that i actually saw, and within 2 days the diarrhea was gone. We are now on day 13 and she has had diarrhea since yesterday.  Can i deworm her a day early? I have gone crazy cleaning & vacuuming my house since i found out, going so far as deworming my 75 lb. dog with Drontal, my 2 year old daughter and both myself & my husband with the over the counter pinworm/ roundworm treatment (the same day as she was treated with the Milbemax)  I now know how hard it can be to get rid of the eggs, & with this 2nd bout of diarrhea i want to do absolutly everything i can do to make sure that she (or us) won't get reinfected.  Should i bathe her? (cringe)  What are the chances that I will have to treat her again (if the diarrhea returns)  Should I be retreating my family?  I only ask, because I called my vet this morning to see if i could dose her early, asked my other questions, and was then told by the vet tech answering the phone that she wasn't even aware that you had to retreat in 14 days, but not to worry because it isn't transmissable to humans, which i know to be false.
Please, i am desperate for help, & with so much conflicting info out there, it is hard to know what is true.

Answer
Hi Angie,

The Milbemax actually does not need to be repeated in order to treat roundworm infections. It only needs to be repeated if you want to provide continued protection against REINFECTION. In that case, treatment once a month is recommended and is plenty to suffice (one dose provides her with continuous protection against infection with worms for one full month). Treatment 13 or 14 days apart will not harm her, but I feel it will be money down the drain, and I don't suspect you're going to see an improvement in her diarrhea.

I don't think bathing your kitty is necessary. Her highest chances of reinfecting herself come from contact with eggs that might stick to her feet from the environment, so cleaning the floors as you have done is more important. If reinfection is your biggest concern, keeping her on a once-monthly treatment of Milbemax is your best bet.

It's hard to say for sure why you were instructed to repeat the Milbemax so early. Some vets like to repeat dewormers in cases of bad diarrhea, even when there is no proof that it's necessary to do so.

I hope Luna's diarrhea will improve once the inflammation the worms had created dies down. But she may have an infection that doesn't respond to the antibiotics you've tried, or an inflammatory condition like colitis or Inflammatory Bowel Disease. In these cases, different antibiotics or anti-inflammatories will be required.

I also feel it's unnecessary to retreat your family. Although transmission to people is possible, it's extremely uncommon. It typically only occurs in very young children who have had their hands in the litter box. And since Luna is worm-free and not shedding any eggs because of the Milbemax, your home is probably much more sanitary than anything your child might come in contact with outdoors.

Good luck!
Jessica