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Why is my puppy losing weight and has diarrhea after deworming?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Large (61lb +) | Male | neutered | 6 months and 11 days old | 115 lbs

I’m really worried about my puppy, Bear is supposed to be a big dog and for 6 months old he is giant! But recently i noticed that he had worms and he’s been on dewormer and he’s having issues with healthy stools, it’s been watery etc. but the thing concerning me after all the works have left is that he is still having bad stools and now he is losing weight withhim two days his collar won’t even fit on him and slips right off and that is so irregular and making me concerned for him. What can i do

1 Answer

Most Helpful Answer

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Answered By Oneal Bogan, DVM

Veterinarian

Published on September 8th, 2018

Hi there. Weight loss in a puppy Bear's age is concerning. It could be the parasite but also diarrhea can cause weight loss quickly. I would recommend taking him into your vet for blood work and fecal testing to diagnose what is causing the diarrhea, and get him the treatment he needs. I hope that helps. Thanks for using Petco Pet Education Center, formerly Petcoach.

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