How Specific are Deworming Agents?

Hi Dr Moffat, just wondering if worm medicine covers all types of worms or if I should have my dog tested for other kinds? He is supposed to get a heartworm test, so am wondering if he should have a fecal exam at the same time. Thank you, T.D.

Dear T.D: Worm medicines are fairly specific with the different groupings of worms Terry.

So Strongid (Pyrantel pamoate) would work for most roundworms, Cestex (Epsiquantel) would work for most tapeworms and some forms of Ivermectin have fluke killing components in them but also work for tapeworms and roundworms. (Note: I consider ivermectin to be a last resort due to its toxicity.)

If you give your dog the heartworm medication (usually that has ivermectin in it) and he actually does have heartworms, the dog could die from an anaphylactic reaction. If you’re giving him heartworm medicine every 6 weeks or less—that wouldn’t happen. BUT if you haven’t given the heartworm medicine for a couple of months and want to re-start, then you should be doing a heartworm test first to be sure the dog doesn’t have heartworm. The medicine is a preventative and will kill the baby forms of heartworm before they reproduce inside the body causing real problems. Certain states have a higher incidence of heartworm so it may be more important to continue the heartworm medicine year round in those areas. I don’t know what the incidence rate is in Michigan where you are. If you travel to states that have high incidence of that parasite, then you’d also want to be more attentive to testing and consistent treatments.

Read more about Heartworm here: https://naturalhealthtechniques.com/specificdiseasesheartworm/

Often in adult animals, parasite eggs won’t show up in the feces (especially when the worm load is very small) so these days, veterinarians would not normally worm an animal unless they actually see evidence of worms on the critter or in the stool sample.

Sometimes I pick up worms through the muscle testing process (especially when the body is ready to release them) and we can treat them with something when the vet’s office won’t see anything to treat.

Natural herbal wormers treat more than one type of parasite. Homeopathics are more specific.

So the short answer to your question is, go for the heartworm test and feel free to do a fecal at the same time, but I doubt your vet will find anything at this point on the fecal test (because it didn’t come up with muscle testing and we’ve already attended to the appropriate internal parasites).

If your dog eats fleas, mice or dead critters on occasion though, you’ll want to re-worm with tapeworm medicine occasionally. Usually bloating, dull coat and sometimes dried tapeworm segments will be evident to help you know when to do that. Adult critters do a pretty good job of resisting roundworms (unlike younger animals and people) but sometimes you need to use the roundwormer preparations and an annual fecal exam can pick that up pretty well. I had to worm my own 8-year old cat last month because I saw roundworms in her feces. Kind of took me aback, but she her coat was a bit drier than usual. Still I expected tapeworms, not roundworms at her age.

Then, if the animal has bouts of diarrhea and you find they drink out of puddles and creeks and lakes you’d have to suspect giardia or other protozoal parasites. Those are way harder to pick up with veterinary testing as giardia needs special stains and multiple tests. I love muscle testing for these kinds of cases because it seems to be really accurate in letting us know how to treat an animal and which product is most effective with the least side effects.

To complicate things even more, Jessica Lynn at Earth Song Ranch has noted that the parasite counts will be higher (especially seen in large animals such as horses/cattle/llamas/goats/sheep) during a full moon and the egg counts will be lower during new moon times. She often uses an herbal wormer for routine stuff and suggests chemical wormers if the herbal ones don’t do the trick but it’s difficult to get dogs and cats to ingest those types of wormers as a general rule.

It’s all pretty involved, but there you go. I hope that answered your question. Denice