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My dog has a soft, fluid-filled lump on her chest. Is it serious?

Updated on September 23rd, 2025

Pet's info: Dog | Labrador Retriever | Female | spayed | 1 year old | 40 lbs

I just noticed this “lump” on my dogs chest. It isn’t hard, it seems to have fluid. She is not acting sick and has not been having any symptoms. Should I be concerned?

5 Answers

Most Helpful Answer

Answered By Ricardo Fernandez, DVM

Veterinarian, Veterinary Oncology Resident

Published on July 31st, 2018

Thanks for using Petco Pet Education Center, formerly Petcoach! This could be a benign or malignant growth. There is no way of knowing what it is just based on its appearance. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have her evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good night!

8Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Kevin Sanada, DVM
Veterinarian
Published on November 19th, 2017
It's not possible to tell exactly what this is from the picture, because there are a few different cysts, or tumors that can look similar to this. This could also be due to some sort of soft-tissue swelling. In order to tell for sure, a vet would need to examine it and likely need to take a sample for evaluation.

I recommend taking Bella to the vet, so they can identify this. It's always best to have this done as soon as possible in case it's something serious.

I hope that helps and all is well with Bella.
1Pet Parents found this answer helpful
Answered By Daniel Fonza, DVM
Veterinarian
Published on August 15th, 2017
Hi there and thank you for using Pet Coach. Due to the rapid increase in size, I would get this lump checked out by your veterinarian. They can perform a simple test by inserting a needle into the lump to see what the contents are. This may be a cyst / abscess / tumor (benign or malignant) and it should have more testing done to try and determine what it is and what the right course of treatment should be. Please let me know if you have any other questions / concerns.
1Pet Parents found this answer helpful
Answered By Dr. Strydom, DVM
Veterinarian
Published on May 22nd, 2023
Hello, thank you for using Petco Pet Education Center, formerly Petcoach.

This looks like a benign cyst. I would just monitor it. If you notice it growing larger then have your vet check it. Sometimes cysts do grow and need to be drained. I, personally, would not be worried about it.

Hope this helps. Best wishes.
4Pet Parents found this answer helpful
Answered By Andrea M. Brodie, DVM
Veterinarian
Published on September 28th, 2018
That is a very interesting looking growth and likely an oversized wart. However there is no way to determine whether this is a malignant or benign growth just by looking at it on a photo, so you need to schedule an exam with your veterinarian who can assess the growth with a hands-on exam. The vet may want to take some tissue from the mass with a very fine needle in order to help determine malignancy.
1Pet Parents found this answer helpful

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