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What's this red lump on my dog's leg? Is it a tumor? When to see vet?
Updated on September 23rd, 2025
Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Male | neutered | 5 years and 3 months old | 55 lbs
My dog has a red lump on his left leg
5 Answers
Most Helpful Answer
Answered By Dr. Massimo Orioles, DVM, Cert AVP, MRCVS
Veterinarian
Published on December 19th, 2021
In this case this lump seems to be a tumor and would need ideally to be checked by your local veterinarian to differentiate in between benign and more sinister ones. The lump seems big enough to be able to take a fine needle aspirate from it without using local or general anesthetic. A small needle can be inserted inside the lump to get some cells out and analyse them.
1Pet Parents found this answer helpfulRelated Answers from Veterinarians
Answered By Dr. Massimo Orioles, DVM, Cert AVP, MRCVS
Veterinarian
Hi and thanks for your request.
In this case a picture of the lump would be essential to determine the underlying nature of it more specifically. I would recommend to send it by email to our customer care service.0Pet Parents found this answer helpful
Answered By David Elbeze, DVM, MRCVS
Veterinarian
Published on January 1st, 2017
This lump needs to be checked and analysed as there are many conditions and types of tumors that could look like that. take Charlie to the vet, they will perform a fine needle aspiration on the growth and send it to the lab for analysis. when the result comes, the vet will advise what needs to be done according to the diagnosis.
1Pet Parents found this answer helpful
Answered By Andrea M. Brodie, DVM
Veterinarian
Published on October 9th, 2018
Unfortunately the photos are not very sharp when I try to enlarge them. The fact that this mass is growing is a little concerning.
This may be a little abscess, cyst or tumor. You should have it examined by your veterinarian as a tumor should be removed ASAP, especially on the leg, as there is not so much skin available to close the incision after removal. An abscess can usually be treated with antibiotics and/or be lanced, and a cyst can be evacuated. Your vet may want to do a fine needle aspirate (he takes some material from the bump with a needle and then looks at it under the microscope) to determine whether the mass is concerning.1Pet Parents found this answer helpful
Answered By Jennifer Summerfield, DVM CPDT-KA
Veterinarian, Certified Dog Trainer
Published on November 20th, 2016
Without seeing the lump, it's hard to say what it might be. Some possibilities would include a localized bacterial or fungal infection, a local inflammatory reaction due to an insect bite or sting, a lick granuloma (causing by excessive licking), or even a skin tumor of some kind. I would recommend having the lump examined by a vet when you are able to - he/she can do some testing if needed to help determine what it is and what treatment is needed.
1Pet Parents found this answer helpful