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Why is my dog's lip swollen on one side, yet he seems normal?

Updated On September 23rd, 2025

Pet's info: Dog | Basset Hound | Male | neutered | 3 years and 8 months old | 53 lbs

My dogs lip is dry and swollen on one side. He is eating and drinking. Acting normal. Does not like it touched. Gums and rest of mouth not swollen or red.

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5 Answers

Most Helpful Answer

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Answered By Shaneez Wallani, DVM

Veterinarian

Published on February 26th, 2019

Toby is a very handsome man! If the area continues to bother him (if it stays swollen and he doesn't want you touching it) I recommend making an appointment to have him seen by a vet for diagnosis and treatment of the issue. If the swelling spreads elsewhere, he develops hives, or he begins to have any difficulty breathing, have him seen by a vet right away, as this could be a sign of a serious allergic reaction. If you are using plastic food or water bowls I recommend switching to stainless steel or glass and washing them thoroughly every day, as sometimes plastic bowls and the bacteria that can live on them can lead to irritation of the lips/ chin. If you think Toby may have chewed on an electrical wire and that may have caused the lesion on his lip, let your vet know right away, as this can be very painful.

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51Pet Parents found this answer helpful

Related Answers from Veterinarians

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    Answered By Anna M., DVM

    Veterinarian

    Published on March 17th, 2020

    Ele could be having a local reaction to a bug bite or sting, or she could have focal swelling from a tooth problem. If the swelling doesn't consistently improve and completely resolve over the next 2-3 days, I recommend having her seen by the vet. If at any point it looks worse, then i'd take her right in to be seen.

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    Answered By Dr. Strydom, DVM

    Veterinarian

    Published on March 26th, 2020

    It could be a contact allergy where that side of his mouth came into contact with something caustic/irritating. I don't really know. If he seems otherwise fine you can try giving him some Benadryl - 50mg (2 tablets) every 8 to 12 hours for a day or so. If no improvement then you should have your vet check him out.

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    10Pet Parents found this answer helpful

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    Answered By Dr. Heidi DVM, CVA, CCRT, CVTP, CVSMT, CVCH

    Veterinarian, Certified Veterinary Acupuncturist, Certified Canine Rehabilitation Practitioner

    Published on May 22nd, 2018

    The most likely reasons that we will see swellings like that on the chin of a dog would be a bacterial infection or an allergic reaction. If the area is becoming more swollen, then I would worry that it is an allergic reaction and would recommend having Winston examined tonight. We commonly see localized swelling from a potential allergic reaction that may only involve one area, but always worry about swelling on the face. If he vomits, is lethargic, or appears to have any trouble swallowing or breathing, it is an emergency and he needs to see a veterinarian immediately. If the area stays the same and does not appear to bother him, then it may be an infection or a mild reaction and your veterinarian should evaluate it to decide on the best treatment plan. Good luck! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

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    Answered By Rebecca, DVM

    Veterinarian

    Published on May 31st, 2017

    It does appear that he may be having a possible allergic reaction or hypersensitivity. Monitor to make sure the swelling doesn't increase and that he has no trouble breathing or swallowing. If it doesn't get worse it is likely self limiting and should resolve over a day or two. If it worsens definitely contact your veterinarian.

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