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Why is my dog lethargic, not eating or drinking after his shots?

Updated On September 23rd, 2025

Pet's info: Dog | Havanese | Male | neutered | 1 year and 10 months old | 13.8 lbs

Hello. Our two year old male neutered havanese received his vaccinations at 2:00 today for rabies, bordertella ,dhlpp. Distemper and leptospirosis. This hyperactive dog is now so lethargic, not eating and not drinking. Any suggestions or concerns. Thank you so much Mrs. Swift

4 Answers

Most Helpful Answer

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Answered By Jyothi Alagappan

Veterinarian

Published on June 8th, 2018

Hi and thank you for using Petco Pet Education Center, formerly Petcoach. He may be having a vaccine reaction. Sometimes it can be painful at the injection site and dogs can be sore. I would recommend calling your veterinarian tonight and letting them know that Wolfie is not feeling great. They may prescribed him some anti-inflammatory medication, fluids or anti-nausea medication to help him feel a little better. Good luck!

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Other Answers

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    Answered By Angel Alvarado, LVT

    Licensed Veterinary Technician

    Published on October 20th, 2017

    This may not be an allergic reaction to the vaccines. An allergic reaction is typically characterized by swelling of the face, vomiting and/or diarrhea. She may be a bit sore from the combination of vaccines. It should pass in 24-36 hours. If not, have her rechecked by your veterinarian. Have a note placed in her record to split the vaccines. If she becomes extremely lethargic or unresponsive or if she has difficulty breathing, then have her examined at the nearest veterinary ER.

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    Answered By Dr. Strydom, DVM

    Veterinarian

    Published on February 13th, 2020

    Yes, I would be a bit worried. He is probably having a mild vaccine reaction. If his symptoms last longer than 24 hours you should have him to the vet for an exam. At this stage you can just let him rest and monitor him. DO NOT give him any over the counter medications.

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    Answered By Jessica Desrosiers

    Veterinary Technician

    Published on January 15th, 2019

    I agree with your vet. Vaccines can make a dog a little tired or lethargic the day after, however if Daisy is still acting like that after 24 hours, or any of her symptoms worsen, then bringing her back to the vet is best to treat any allergic reactions or other underlying issues that may be the cause. You can try to encourage some eating with a little bland boiled chicken and rice, however if symptoms continue, seeking vet care is best.

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