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Dog not eating, vomiting, and lazy after deworming. What's happening?

Updated on September 23rd, 2025

Pet's info: Dog | Labradoodle | Male | unneutered | 1 year and 7 months old

after deworming bruno did not eat his meal the next day . and even vomitted. he ate only once and that was very little dry food. today again he is not eating anythinh and behaving very lazy. I can hear sounds from his stomach. i tried to feed him but he is not eating. what is happening ?

4 Answers

Most Helpful Answer

Answered By Stacey Anstaett, DVM

Veterinarian

Published on January 25th, 2019

I am sorry to hear that Bruno isn't feeling well. Sometimes after they are dewormed, they feel a little punky because if they have a large load of intestinal worms that die all at once, those worms can release inflammatory components that upset the GI tract.
If he still isn't back to himself, take him to your vet. He may have another cause go gastroenteritis, or he may have eaten something he shouldn't have (such as a toy, etc) and may have an intestinal blockage.

I hope he's feeling better now! I am sorry for the delay in our answering of your question. Thank you for asking Petco Pet Education Center, formerly Petcoach!

5Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Linda G, MS, DVM
Veterinarian
Published on February 1st, 2019
Hello. As long as Brownie is still drinking water & not vomiting, there is no need to panic. The worms & wormer may have upset his stomach. For now, I would pick up some jarred pureed meat baby food ( like turkey ) that does not have onions or garlic in it. Try feeding him about a teaspoon every hour or so. I would also try rubbing some light karo syrup on his gums at the same time to keep his sugar levels up. If he refuses to eat , or continues to vomit over the next 24 hours, you will have to find a veterinarian to help sort things out for you & Brownie. I hope Brownie is feeling better soon & thanks for using Petco Pet Education Center, formerly Petcoach.
1Pet Parents found this answer helpful
Answered By Ann Dion, DVM
Veterinarian
Published on June 9th, 2019
Hello and welcome to Petco Pet Education Center, formerly Petcoach.

The image you have provided looks like there are roundworms present. If there is a very large worm burden (large numbers of worms), this can cause animals to not be able to eat, and have vomiting and diarrhea.

You need to get him a dewormer that covers for 'roundworms'.

I also recommend getting him to a vet as soon as you can, as medication to stop the vomiting is a good idea.

Best of luck with Bolt! I hope he feels better soon!
1Pet Parents found this answer helpful
Answered By Lauren Jones VMD
Veterinarian
Published on June 18th, 2017
I'm sorry to hear that Cosmo isn't feeling well. I always say, better out than in when it comes to intestinal worms! I would not be surprised if more worms are passed either in his stool or vomit after the dewormer. It is possible that these intestinal worms are the reason that he has been vomiting and lethargic, but he could also be experiencing stomach upset from a virus (including parvovirus if he has not been fully vaccinated), stomach upset from different foods or treats, or a foreign body intestinal obstruction. Remember that young puppies are more susceptible to the effects of dehydration and hypoglycemia than adult dogs. Since Cosmo is still refusing food and lethargic, I recommend taking him to a vet urgently for evaluation. He will likely need some diagnostic testing, including abdominal x-rays to try to rule out suspicions of an intestinal foreign body obstruction. I hope this helps and that he feels better soon!
1Pet Parents found this answer helpful

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Related Questions

Health & Wellness

Why is my puppy pooping white goo and not eating after deworming?

Poor Bruno! It’s possible it’s related to the deworming but it’s also possible there’s another cause such as a viral infection, dietary indiscretion, parasites or bacteria over growth. Usually a reaction to an oral medication will happen within 24 hours. Since Bruno is young and small, I recommend to have him seen by his veterinarian today if possible. Small breed puppies are susceptible to low blood sugar and this will cause seizures and can be fatal if not treated. If puppies don’t eat, they run the risk of developing low blood sugar. He is not feeling well and that’s why he’s not eating. It’s always best to be safe with these little ones. Offer him cooked chicken breast and plain boiled white rice. Canned puppy food would also be a good option. If he shows any signs of significant lethargy, trouble walking or seizures, smear something sugary like Karo syrup on his gums and get to the vet’s office immediately. Unfortunately, many products now have xylitol in them to act as a sweetener and this is toxic to dogs so you want to read your labels. I hope he starts feeling better quickly! I hope this is helpful and please feel free to post any additional questions.

Updated on September 23rd, 2025

Why is my dog still vomiting and not eating after deworming?

Hi, and thanks for your question. These signs could be compatible with an inflammation infection of the gastrointestinal system and surrounding organs (like pancreas and liver). The death of the worms can cause an obstruction. A clinical examination at your local veterinarian is immediately essential to confirm these clinical suspicions and treat appropriately. Antibiotics and possibly further investigations (like abdominal imaging as ultrasound or radiographs) may be needed. 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 23rd, 2025

Food & Nutrition

Dog not eating after deworming. Is it his stomach or vegetables?

Hello and welcome to Petco Pet Education Center, formerly Petcoach. It is ok for your dog to eat vegetables, they are good for dogs. Avoid onions, garlic, grapes, chocolates and raisins as these are toxic. Stick to the normal vegetables like broccoli, carrots, potatoes, cauliflower, peppers. No eating for 2 days after deworming is not normal. I recommend that you have him seen by his vet, as I am worried he has some other condition aside from worms that are making him sick. Best of luck with Binnu, I hope he feels better soon!

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My dog won't eat after deworming. Is this normal? What to do?

It is quite possible that he is nauseous from the medicine or he had a lot of worms which are now dying and that is causing him a tummy ache. Don;t feed him for 12 to 24 hours and then offer him some bland food such as boiled white rice and boiled white boneless chicken. Feed him small portions often. When he has regained his appetite he should be fine. There is a possibility that he will get diarrhea as well for a day or two as the body is going to try to get rid of the worms as quickly as possible.

Updated on September 23rd, 2025

Puppy lethargic, wobbly, not eating after roundworm meds. Normal?

Poor Kai! I'm sorry to hear that he isn't feeling well and I understand your concern! In some puppies with a significant burden of roundworms, vomiting and diarrhea can occur as a means of expelling the worms. This also can cause inappetence from nausea and mild lethargy as a result. Although rare, intussusception (essentially intestines that telescope into one another) can occur in cases of parasitism, which can cause vomiting, lethargy and inappetence. At this point, monitor Kai for changes tonight and try to tempt him to eat with boiled white meat chicken and white rice as a bland diet. If he is still lethargic and not eating by the morning, he should be examined by his vet. The greatest likelihood is simply that his body is working to expel the roundworms.

Updated on September 23rd, 2025

Health & Wellness

Is my puppy sick after deworming? Medicine or serious illness?

Hi,t hanks for using Petco Pet Education Center, formerly Petcoach! Dewowmers have the potential to cause an upset stomach such as vomit, diarrhea and decreased appetite. Though I am worried something else is going on since you lost a puppy recently. I worry most about parvo virus in puppies this age, especially if they are yet to be vaccinated. I would have this puppy seen today by your Vet and tested for parvo virus as it is VERY contagious and if it is the cause it will likely affect the entire litter. If it isn't parvo the Vet can at least get this puppy feeling better and prevent dehydration. Good luck!

Updated on September 23rd, 2025

My puppy threw up and won't eat after wormer. Is this normal?

I am not sure the type of dewormer or the vaccines that you used but vomiting often, lethargy, and not eating are not typical 2-4 days after vaccination and deworming. It is very concerning that she is having these signs and she could have an infection or possibly have a parasite that was not susceptible to the dewormer that you used. She really should be seen by a vet to determine the cause and treat. She may need an anti-vomiting injection, antibiotic, antacid, gastrointestinal protectant, dewormer, and/or other medications to treat. You could try to find a clinic that would work out a payment plan or apply for care credit and have her seen. Hope she feels better soon!

Updated on September 23rd, 2025

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