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Why is my puppy's leg still swollen with a persistent sack after injury?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | unneutered | 3 months and 18 days old | 15 lbs

Hi. My puppy was hit on his leg 3 days ago. His leg is very swollen and there is also some kind of flabby sack that has developed under his leg that continues to swell. A vet told me that a bone had damaged the muscle in the lower abdomen and caused the swelling. He was given painkillers and prescribed Augmentin The swelling in the leg has reduced, but the swelling of the sack/muscle or whatever it is has continued.

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1 Answer

Most Helpful Answer

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Answered By Kevin Sanada, DVM

Veterinarian

Published on April 1st, 2018

Sorry to hear about poor Oreo. The swelling that you are describing is most likely due to a seroma. This commonly happens after trauma is just an accumulation of fluid under the skin. These are not harmful and do take a week or two to subside. Sometimes they can persist and need to be drained. Unfortunately, without being able to evaluate the swelling in-person, I can't tell exactly what this is. It could also be due to a hernia, or abscess and the only way to tell for sure would be a physical examination and needle aspirate. The best option is to have your vet reevaluate Oreo to ensure all is OK. I hope that helps and Oreo gets better soon.

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