Dog ate chocolate?

ask a vet

Does Hartz kill roundworms?

Species: Dog
Breed: lab mix
Age: 1-2 years
well, this one time when I had a lab mix puppy that wasn't vetted or wormed or anything because she came from a super rural farm in MN. She was 12 weeks old and I used those flea and tick drops on her (they were from Wal-mart...Hartz brand) and the next morning I went to take her outside to potty, and there were dead worms all over the crate floor! there were A LOT! sp I was wandering.....the fleas and tick drops can kill worms too?...because it sure looked like it to me....

Related Article: How to get rid of fleas!


Online vet, Dr. Marie

Dr. Marie replied:

Thanks for an interesting question!

Hartz flea drops are not supposed to treat roundworms (which is most likely what you saw). The ingredients in Hartz flea and tick drops are mostly phenothrin and some methoprene. Both of these have some effectiveness against fleas. (I say some because I find that these products do not work well for fleas.)

There is no claim on the label that they work for intestinal parasites. I did some research for you to see if there was any connection but could not find any.

However, my theory is that the ingredients do have some effect on roundworms. Many of the topical medications do get absorbed through the skin and can have systemic effects as well.

It is definitely a good idea to repeat a treatment with a dewormer that is meant for roundworms as there may still be more there. You will also want to repeat it in 10-14 days to make sure that you cover all the life stages.

As an additional note, I really don't recommend over the counter flea products like Hartz. I have seen so many cases where they don't work and in some cases they can be toxic especially if applied to a young puppy or to a cat.

I hope that helps!

Dr. Marie

---This question was asked in our Ask A Vet For Free section.---


Do you have a pet website? Interested in learning more about SEO for Wix?


Check out our dog age calculator and cat age calculator.

Want to receive pet coupons, vet advice and info on new pet products in your inbox?

* indicates required

We'll only send you great stuff, never spam. Unsubscribe any time.

Disclaimer: Although Dr. Marie is a qualified veterinarian, the information found on this site is not meant to replace the advice of your own veterinarian. AskAVetQuestion.com and Dr. Marie do not accept any responsibility for any loss, damage, injury, death, or disease which may arise from reliance on information contained on this site. Do not use information found on this site for diagnosing or treating your pet. Anything you read here is for information only.

Search for similar questions:

ask a vet

Popular questions...

Unneutered dog bit child. Hello Dr. Marie, Our 9 year old Border Collie has no history of aggression or... (11473 views)

Dog can't jump. My dog has a hard time standing up from the sitting position. Occasionally, he will... (14257 views)

Flea problems. My dog Roxie has had a flea dip and has had her last months flea treatment, but she... (11098 views)

medicine for collapsing trachea We are leaving for a car trip with Skiggy. She has a collapsable larynx and gets... (12002 views)

Incontinence and balance issues. We have a dog breed and age unknown is a stray all of a sudden she has started... (19031 views)

Anxious cat - medicine? Hello, My Cat Guen shows MANY attention seeking behaviors. She chews chords,... (22492 views)

Diabetes and IBD. Hi Dr. Marie- This one is long and complicated, but hopefully it makes sense! I... (11079 views)

Snapping noise in joints. Doctor, We have two labs (chocolate, and black). They love to run, fetch, play, and... (16087 views)

Dog with small pink lump. My dog has a smallish lump on her back which is sort of pinkish in colour but dosn't... (21089 views)

Introducing kittens. hi, i have a 5 month old kitten, and have introduced an 8 week old kitten to the... (10402 views)

See all questions...

Dr. MarieDr. Marie is a veterinarian who practices in a busy animal hospital in Ottawa, Ontario. She created Ask A Vet Question as a resource for good, accurate veterinary advice online. Dr. Marie treats dogs, cats, hamsters, guinea pigs, and rats. She has been a vet since 1999.

Is an online vet visit just as good as a trip to your veterinarian? No! But, many times, asking an online veterinarian a question can help save you money. While Dr. Marie can't officially diagnose your pet or prescribe medications, she can often advise you on whether a vet visit is necessary. You can also ask Dr. Marie for a second opinion on your pet's condition.