Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

Why is my puppy having diarrhea after deworming or new food?

Updated On September 23rd, 2025

My 3 month old golden retriever puppy was given a deworming med for tape worms on 12/29. Today he had diarrhea. We also started mixing new dog food with his old food 3 days ago. (3 parts old food and 1 part new food) Could the diarrhea be from the worm meds or from the new food?

1 Answer

Most Helpful Answer

Image profile

Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on January 6th, 2018

Great question! It could be from both honestly. You can see diarrhea after giving a deworming medication, it means the dead worms are moving through the GI tract and it's working. You are doing the right thing by mixing the new dog food with the old, but it could be his body doesn't like the new food. I would try feeding him a bland diet of boiled white meat chicken (no bones) and white rice in small amounts a couple of times a day for a few days to see if that helps with the diarrhea. Should the diarrhea clear up, then go back to mixing the old food with the new food. If it does not clear up, have him seen by a vet. Good luck, I hope this helps!

Vote icon

1Pet Parents found this answer helpful

Related Questions

Petco Pet Education Center
Health & Wellbeing
My pup is Golden retriever 5 months old. He is 15kg. He was given 2 deworming tablets for two days. After 12 hours of ii dose, he had watery diarrhea for goir times. Is it notmal. Suggest medication pl
No I would not expect diarrhea as a direct result of deworming, but the stress of the vet visit or even the vaccine that he likely received at the same time could cause temporary diarrhea. You can feed him boiled chicken and rice for 2 days. If he's still having diarrhea after 48 hours, or it's liquid diarrhea at any point, he needs to go to the vet.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My puppy is 10 weeks old. He got dewormed last week and just today got diarrhea. What should I do?
These signs could be compatible with a colitis, which is an inflammation of the last part of the colon, usually related to dietary indiscretion. As a first approach, I would suggest to start feeding with a bland diet based on boiled chicken and rice in small portion every 6 hours for the following 48hours. Then gradually reintroduce the normal diet over 5 days. I would definitively recommend a veterinary check up if the signs persist or you notice vomiting, lethargy or inappetence. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi. I have a 6 week old puppy. He was dewormed on thursday. He has been having diarrhea. Besides that there are no other symptoms. Still very energetic. Still eating. Its not dark in color and no blood presented. Should i be concerned? Should i withh
Poor pup! The diarrhea could be due to many conditions including eating something he shouldn’t have, bacterial over growth, parasites, the medication or even organ disease. If the diarrhea has continued beyond 24 hours, I recommend to have him examined by the veterinarian. With continued diarrhea, there are often bacterial shifts in the gut that will make matters worse regardless of the initial cause. Make sure to bring in a sample of fresh stool. The doctor will check him for parasites and bacterial over growth. Puppies can have trouble regulating their blood sugar so they should not be fasted very long. In general, I don't recommend to fast puppies at all. Some times a bland diet can help and then a slow, gradual introduction to the normal food can be done. A bland diet can consist of 25% boiled white meat chicken and 75% boiled white rice. This should all be plain. again though, because the diarrhea has lasted almost 5 days, with the bacterial shifts, I recommend to have him examin
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
I have a 13 week old puppy almost fully vaccinated, he has been de wormed. He has had constant diarrhea since we got him.
There are other parasites that can cause diarrhea that are not killed with the routine dewormers. I would recommend a full fecal exam with your veterinarian to see if there is a different medication that may be helpful. Sometimes probiotics and a bland diet may be helpful as well.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
I got her a few days ago and she has had diarrhea since I've had her I took her to the vet and they did a fecal exam but everything was negative. The people I had bought her from had started her on pedigree and then switched her to ol Roy and when I
Dogs will frequently develop diarrhea from a diet change which is why it is recommended to slowly transition your pet from one food to another. Since worms have been ruled out, it is likely that this is your pup's issue, although there may be many reasons for diarrhea including infection, allergies and other disorders. If the diarrhea does not resolve in another day or two, you should take her back to your veterinarian to determine the underlying cause of the diarrhea.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Dog had roundworm dewormer last dose on 28th and now had diarrhea all day which has now turned green.
It is possible that if your dog had a severe round worm problem, all the dead worms now are causing the intestine to try and get rid of them as fast as possible. This is achieved by diarrhea. I would wait for another day to see whether it goes away by itself. If not, then I suggest you withhold food for about 12 hrs and then feed some bland food (boiled rice and boneless chicken) for a day and then slowly transition back to his normal food. If that does not clear it up, it is time for a vet visit.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi my dog has diarrhea and has for two days now me and my husband picked him up from a guy who was really mistreating him amd was starving him... Yesterday i gave him some dewormer hoping that was the reason but he has been eating pedigree soft food
Oh no, poor Fat Boy! You are correct that worms could be causing the diarrhea, but if he was being starved, the sudden change in diet could also be causing the diarrhea. I can give you a home remedy to try to see if that helps. Withhold food for 12-24 hours, then feed a bland diet of boiled white meat chicken (no bones) and white rice in small amounts several times a day for a couple of days. Then slowly add back in his normal diet. If the diarrhea continues on the bland diet, he starts vomiting food, stops drinking water, starts vomiting water, or becomes very lethargic, he will need to see a vet right away. With the deworming, he will need another deworming treatment two weeks after the first to kill all the worms. After that, he should be dewormed every three months.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi my dog got his vaccine and deworming on saturday.it lost its appetite and diahrrea.im worried plz help.its 45 days old puppy.
The diarrhea could be caused by the deworming treatment. Feed Rudy a bland diet of boiled white meat chicken (no bones) and white rice in small amounts several times a day for a couple of days. Then slowly add back in his normal diet. If the diarrhea continues on the bland diet, he refuses to eat the bland diet, he starts vomiting food, stops drinking water, starts vomiting water, or becomes very lethargic, he will need to see a vet right away. Best of luck.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi! My dog is 6 weeks old.He hasn't been eating since yesterday night. He has diarrhea as well from yesterday. He was given a dewormer yesterday. What should i do to make him eat? What kind of food can be given?
Hi, and thanks for your question. As a first approach, I would suggest to start feeding with a bland diet based on boiled chicken and rice in small portion every 6 hours for the following 48hours. Then gradually reintroduce the normal diet over 5 days. I would definitively recommend a veterinary check up if the signs persist or you notice vomiting, lethargy or inappetence. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
my little Labrador who is 42 days old now , his poop is watery like very watery and he had his first vaccine 2 days before and i dewormed also ,
If Choco was given deworming medication recently, it could be the cause of his diarrhea. The medication will be killing any worms, and that can lead to diarrhea. It could also be that he has a GI illness. I can give you a home remedy to try to see if that helps. Withhold food for 6-8 hours, then feed a bland diet of boiled white meat chicken (no bones) and white rice in small amounts several times a day for a couple of days. Then slowly add back in his normal diet. If the diarrhea continues on the bland diet, he starts vomiting food, stops drinking water, starts vomiting water, or becomes very lethargic, he will need to see a vet right away. Best of luck, I hope this helps!
Updated on September 24th, 2025

Related Searches

Dog Food Dog Dewormers & Worm Medicine Prescription Dewormer for Dogs Dog Health & Wellness Prescription Dog Digestive Medications Dog Food With Grain Wet Dog Food Sensitive Stomach Dog Food Prescription Dewormer for Cats Premium Dog Food Natural Remedies Dog Dewormers & Worm Medicine WormX Dog Dewormers & Worm Medicine HomeoPet Dog Dewormers & Worm Medicine Earth Animal Dog Dewormers & Worm Medicine WormX Dog Health & Wellness Elanco Dog Dewormers & Worm Medicine PetArmor Dog Dewormers & Worm Medicine Iverhart Max Dog Dewormers & Worm Medicine Sentry Dog Dewormers & Worm Medicine WormX Dog Supplies
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored