Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

My dog has a hard, baseball-sized lump on his back. What should I do?

Updated On September 23rd, 2025

Pet's info: Dog | Dogo Argentino | Male | 3 years and 8 months old | 70 lbs

My dog has a baseball size lump in his back. This developed in within 60 days. We didn't see any changes in his personality or behavior at all , nor to the way he eats or sleep. The lump is not a bother to him as I touch it without any reaction to pain or any indication or infection. The mass of the lump is hard and the diameter is like a baseball.

1 Answer

Most Helpful Answer

Image profile

Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on April 20th, 2018

This lump on Messi could be a cyst, a benign tumor, or a malignant tumor. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of it's cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Given that it has developed within the past 60 days and gotten as large as a baseball, I would give your vet a call first thing in the morning to make an appointment to have this seen and treated. Best of luck!

Vote icon

3Pet Parents found this answer helpful

Related Questions

Petco Pet Education Center
Health & Wellbeing
My cocker spaniel has a mass on her shoulder and its the size of a baseball what is it???
Without seeing the actual mass and palpating it, it is impossible to give you an exact diagnosis. Any mass this size is very concerning, as it could be a large tumor, a large hematoma or a cyst or an abscess. Seeing that Chloe is fairly heavy for her breed, this could also be a harmless fatty tumor (lipoma). It would be best to make an appointment with your veterinarian for an exam. He can then look at the mass and determine whether it needs to be removed or can be drained.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
We’ve just discovered a small grape-sized place on the lower right hind leg of our dog Simba. It’s hard, moves a little with manipulation, is uncomfortable for him when we touch it, the skin isn’t red or hot with fever, & there isn’t a “head” on the
You are correct that this lump on Simba could be a cyst, a benign tumor, or a malignant tumor. The only way to know for sure is to have him seen by a vet for it, and I'd recommend giving your vet a call on Monday to set up an appointment for him. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of it's cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause the lump is found, the vet can discuss treatment options with you. Because it is uncomfortable for him when you touch, having him seen next week sometime is best. I hope this helps!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
I have an 11 year old shih tzu maltese. She's had this hard lump on her back for a while now, probably over a year. It got bigger over time. I saw a vet about it and her tendency to throw up (she's thrown up mucus for years, i believe due to anxiety.
Hello, thank you for using Boop by Petco. Chances are that this is a sebaceous cyst. Sebaceous cysts are usually harmless, sack-like growths with a lining that is not cancerous. In dogs, most cysts develop from hair follicles. These cysts typically appear as single, clearly defined, firm or soft lumps located in the skin or just beneath it. They are often between 0.5 to 5 centimetres in size and may sometimes have a bluish colour. A cyst can release a thick, gray-to-yellow-brown cheesy substance if it bursts. Other terms for sebaceous cysts in dogs include infundibular or follicular cysts. The lump needs to have a fine needle aspirate (FNA)/cytology to be sure of that diagnosis. Here is a link about the procedure and why it is done. It does not require anesthesia. ( https://vcahospitals.com/know-your-pet/cytology-fine-needle-aspiration-fna ) If it is a sebaceous cyst, it will be very obvious once the vet introduces the needle into the lump. Hope this helps. Best wishes.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Small hard knot on my Poodle mix’s back on the right side. Normally his knots pop and release fluid, but this one is solid. When I apply pressure to it, he wants to nip me, which is indicative of pain. There is no hair loss, no discoloration. It has
Thanks for using Boop by Petco! This could be a benign or malignant growth. 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 him evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good night!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
1.5 yr old dog, found a flat feeling lump on shoulder last month, seems to be getting larger. What is this lump likely to be?
In a young dog, this lump is likely a cyst, a lipoma, or benign tumor. Any suspicious lump should be examined by a vet. The vet can do a fine needle aspirate on it. To do this, the vet sticks a needle into the lump to get a sample of its cells, and examines them under the microscope. It's relatively quick to do, and usually painless for the dog. Given that it's been growing larger, I would have your dog examined by a vet tomorrow.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
So for the last month or so.... my dog has had this lump on her stomach. Now, it’s grown a bit bigger over time. I’m not sure if it’s a lump that could be harmful to her or not. But it doesn’t seem to hurt her if we touch it. So, could it just be a n
It's concerning this lump has gotten bigger, and it could be a cyst, a benign growth, or a malignant growth. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. Give S's vet a call to make her an appointment.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My 8yr Staffie has a golf ball sized lump on his inside back right leg. One vet said it was a boil, but I'd like another opinion. I will also add a photo.
This lump needs to be checked and analysed as there are many conditions and types of tumors that could look like that. take him 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.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi my dog has had this lump on her front right leg for about a month now and out of no were it got very big it is not solid it feels like fluids are inside but also doesn’t seem to bother her but I no it does I need answers so bad
Oh that's quite large! This could be a cyst, benign tumor, or a malignant tumor. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. Give Mj's vet a call to make her an appointment. Best of luck.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog brooks has a round hard lump / bump inside of her on her back below her neck and it hurts her when touched. What could this be ?
This could be a benign or a malignant growth. It could even be a cyst. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. Give Brooks's vet a call to make her an appointment. I hope this helps!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog is growing a big hard ball on her stomach and I’m wondering what it could be because it doesn’t seem to bother her.
I'm concerned this ball could be something serious like a growth. This growth could be malignant or benign. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. Give Princess's vet a call to make him an appointment.
Updated on September 24th, 2025

Related Searches

Dog Supplies Dog Toys Dog Food Dog Health & Wellness Dog Medicine and Prescriptions Antifungal Medication for Dogs Dog Balls Plush Dog Toys Dog Blood Pressure Medication Pet Jerseys & Sports Gear DOG by Dr Lisa Lantus Dog Medicine and Prescriptions Lantus Prescription Dog Insulin & Diabetes Medication Dermalone Antifungal Medication for Dogs Prednisone Dog Pain Relief & Arthritis Meds Lambwolf Dog Balls Lantus Solostar Dog Medicine and Prescriptions Dermalone Dog Medicine and Prescriptions Lantus Solostar Prescription Dog Insulin & Diabetes Medication Prednisone Dog Medicine and Prescriptions
image
Have A Vet Question?

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

Book Now

Sponsored