Skip to content


    Exciting News for WebMD Members!

    We've been busy behind the scenes building new message boards for you. You'll have new and easier ways to find messages, connect with others, and share your stories.

    And, this will all be available on your smartphone or other mobile device!

    What Do You Need to Do?

    The message board you're used to will be closing in the coming weeks. While many of your boards will be making the move to our new home, your posts will not. Want to keep a discussion going? Save posts you want to continue (this includes your member profile story), so that you can re-post them in the new message boards.

    Keep an eye here and on your email inbox, we'll be back in touch soon to give you all the information you need!

    Yours in health,
    WebMD Message Boards Management

    Includes Expert Content
    Mosquito larvae in my cat's water fountain!
    kittyquest posted:
    Help! When I went to clean my cat's water fountain tonight, I found lots of black worms (mosquito larvae, I think) swimming around in one of the nooks & crannies where water stands. I'm soaking the fountain in hot water and vinegar right now, but should I just throw it out? And, more importantly, are my cats in any danger if they ingested larvae? One of them already has a heartworm. I'm calling the vet & taking litter samples over first thing in the morning but was hoping for advice tonight because I'm really worried.
    Byroney_WebMD_Staff responded:
    Kittyquest, thanks so much for posting.

    How are your kitties doing? What did your vet have to say? This article on Heartworm in Cats doesn't specifically mention the larvae (that I saw) so hopefully your vet can address that. I would think a thorough cleaning would get rid of any issues, but again, check with your vet for an expert answer.

    Let us know how you and the kitties are doing,

    Every dog has his day - but the nights are reserved for the cats ~ Unknown
    Drew Weigner, DVM, ABVP responded:
    Mosquito larvae will not hurt your cat but it's pretty yucky! It does show that you have a severe mosquito problem and that your cats are at risk for getting Heartworms, as one already has (they're transmitted by mosquitoes and are blood parasites, so they won't show up in stool tests.) Your other cats should be on Heartworm Preventative if they test negative. You can kill the larvae with a 10% bleach solution but don't forget to change the filter in the fountain as well.

    Drew Weigner, DVM, ABVP
    The Cat Doctor
    Board Certified in Feline Practice

    Helpful Tips

    Excellent website for information on parasites in dogs and catsExpert
    I just conducted a seminar and hands-on demonstration on diagnosis of fecal parasites to veterinarians and technicians. An excellent ... More
    Was this Helpful?
    33 of 48 found this helpful

    Report Problems With Your Medications to the FDA

    FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

    Learn more about the AVMA

    WebMD Special Sections