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Ask the Veterinarian/Too much dewormer?


Hi, thanks for taking the time to view my question!
I am concerned that we gave our pup too much dewormer.  Here's the story: On Sunday, we found our dog with poop all over the crate.  Upon cleaning, my husband discovered roundworms.  I bought Sentry WormXPlus and gave him one dose which had 114mg pyrantel.  He is a 6 month old boxer who weighs about 40lbs.

My husband, not asking beforehand, thought he had to give the dog another dose on Monday morning.  There enters an additional 114mg pyrantel.  Fast forward 5 hours and there's another mess, this time I had to clean up.

I went to the vet to get him Heartgard Plus since I read it kills roundworms.  Since he's 40lbs, they said it was okay for me to give him a dose for 51-100lb dogs that day, Monday.  That was an additional 227mg of pyrantel.

So my 6 month old, 40lb boxer had 455mg of pyrantel in 24 hours.  It just dawned on me now that this is probably bad.  Not emergent but still concerning.  Do you think he will be okay aside from just diarrhea for a couple days?  He's not dehydrated, and he's still eating.  The stools are malodorous and impossible to pick up, there is no solidity whatsoever in the stool.  I would say it's almost like a gush.  Please excuse the graphic nature of the description, but I have to be clear about it!

Your opinion would be appreciated!

Pyrantel is a fairly safe wormer. He will probably only get diarrhea from it but if he starts vomiting or shaking, or stops eating, then you should see a vet right away.

Let it clear out of him and just give him his Heartgard monthly. That will keep him worm free!  

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Jana Connell RVT, CVT


PLEASE READ BEFORE SUBMITTING TO ME: I am NOT a vet and do NOT diagnose diseases. That is only for a licensed Veterinarian to do. I will give you suggestions and steer you toward calling your vet for help. You can call the vet's office and talk to the technician there or the vet at times. Don't be afraid to call them! If you have a serious issue with your pet please post it to one of the veterinarians in here- I will tell you the same thing in my answer. IF your pet is injured or in an emergency situation, CALL YOUR VET- Do not wait and post in here. Just call the vet's office and get them in to see the vet right away. Critical treatment time is lost if you seek answers here when you should have your precious pet at the vets!! Don't sit at home waiting for an answer when your pet is critically ill or injured!! I can answer most questions about small animal and wildlife care as well as small animal nutrition. I can also answer questions about all phases of dental care for small animals. I DO NOT answer questions about birds (unless it is wildlife or songbirds) or HAMSTERS/GERBILS/CHINS/GUINEA PIGS/REPTILES/FROGS/RABBITS/PET BIRDS OF ANY KIND so please submit these questions to the appropriate sections. I, as well as other experts in here, do NOT do homework questions- that is for YOU to do! Please respect these rules for all of us. Thanks!


I have over 42 years experience in the field of veterinary medicine. I specialized in small animals and did wildlife rehab for over 25 years, mostly raptors, squirrels and opossums. I am a Small Animal Nutritional Consultant with 6 certificates from Hills Pet Foods, CNM and Purina. I also specialized in Small Animal Dentistry which is a field I truly love. I also Teach Veterinary Technology to working technicians who are studying to take their California Tests to become Licensed Technicians. They have to take both the VTNE (Veterinary Technician National Exam) and the California boards.

Audubon,World Wildlife Federation, American Society of Veterinary Dental Technicians.


Licensed with California and Oregon, RVT and CVT. Certified Veterinary Dental Technician Have over 1500 logged hours of Continuing Education Credits(that means I keep up to date!).

Awards and Honors
Nominated for Expert of the Month for the last 5 years.

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