Petco Text Logo
Petco Pet Logo

My dog has a rapidly growing bump. What could it be before the vet?

Updated On September 23rd, 2025

Pet's info: Dog | Jack Russell Terrier | Female | spayed | 10 years old | 13 lbs

This bump grew almost overnight on my dog. I am taking her to the vet but they can't get her in until Friday. Any ideas what it could be?

This question includes photos that may contain sensitive content. Click to view.

View more to consider that the photos may include sensitive content.

4 Answers

Most Helpful Answer

Image profile

Answered By Kevin Sanada, DVM

Veterinarian

Published on March 6th, 2018

Bumps that appear rapidly are usually some sort of fluid-filled mass. This may simply be a blood blister, but it's also possible that it's a type of tumor that is filled with blood (hemangioma, or hemangiosarcoma). As long as she's otherwise normal, she will be fine to wait until Friday for your vet to look at it. They can inspect it closer and take samples to give you a better idea of what it is. I hope that helps and all is well with Mya.

Vote icon

1Pet Parents found this answer helpful

Related Answers from Veterinarians

  • Image profile

    Answered By Daniel Fonza, DVM

    Veterinarian

    Published on August 6th, 2017

    Hello and thank you for your post! It is difficult to tell what these bumps are exactly, but what you are describing sounds like what we call a hemangioma. These bumps are typically benign if that is what these are. Dogs that are in the Sun a lot are more predisposed to developing hemangiomas. However, that being said, hemangiomas Can potentially turn into a malignant cancer. Hemangiomas can turn into what we call hemangiosarcomas of the skin. To prevent these from turning to malignant masses, you can have these easily removed or frozen off at your vet's clinic. Another possibility is an insect bite causing a blood blister. Hemangiomas typically will occur in the areas that you're describing but can show up anywhere. I would schedule an appointment with a vet if you are concerned and more are showing up to have them removed and to be sure of the suspected diagnosis. I would not say this is urgent but the sooner you address it the better. I hope this helps guide you in the right direction. Please contact me if you have any other further questions or concerns. I am also available via consultation.

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By Jennifer Summerfield, DVM CPDT-KA

    Veterinarian, Certified Dog Trainer

    Published on April 28th, 2019

    Hi there. From what I can see in the photo, these bumps look consistent with a type of tumor called a sebaceous adenoma, which is a benign skin growth that is common in older small breed dogs. Sebaceous adenomas are harmless, and do not normally require any kind of treatment unless they are particularly large or located in an area where they're constantly being bumped and causing bleeding or drainage. In that case, they can normally be surgically removed without much difficulty. To be safe, I would recommend having them checked by your veterinarian in person, since it's not possible for us to make a definitive diagnosis from a photo. :)

    Vote icon

    13Pet Parents found this answer helpful

  • Image profile

    Answered By Jessica Keay, DVM

    Veterinarian

    Published on August 21st, 2017

    I am sorry to hear about Remi! While we can see some cancers cause many bumps on the skin a more common cause would be a skin infection. We can have skin lesions develop as a result of bacterial infection, fungal infection, allergies, or parasites. I would recommend a visit to your veterinarian. They can examine this bumps and may recommend some testing (such as skin scraping to test for parasites, impression smear cytology to check for bacteria or yeast, biopsy if cancer is suspected) to help determine the cause and therefore the appropriate treatment. This may be an easily treatable problem.

    Vote icon

    1Pet Parents found this answer helpful

See More Answers
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Sponsored