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Dr. K
Dr. K, Veterinarian
Category: Dog
Satisfied Customers: 7544
Experience:  13 years experience as Veterinarian
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My dog has a big bump on his head. It just got larger not

Customer Question

My dog has a big bump on his head. It just got larger not so long ago. It is also discharging something. he is not in pain and seems to be the same active dog.
Submitted: 9 years ago via PetPlace.
Category: Dog
Expert:  Dr. K replied 9 years ago.
Where on your dog's head is this bump located?
How large is it (diameter in inches or cm.)?
What color is the discharge?
How long has the lump been present?

Dr. K
Customer: replied 9 years ago.

Right on the top of his head closer to his right ear.

Size: I have not messured it but it looks like a good 3in wide and an 1in high

color is hard to say he is a white boxer with some brown spots, It looks like a dark brown to black (maybe its blood)

the bump has been their for a while it was the size of a penny then it would go away.

When it came back I thought he had hit himself and was waiting for it to go down like the last time. This time the bump just got bigger. But like I said he is acting normal without pain. Hope this helps I can email a picture if it helps

Expert:  Dr. K replied 9 years ago.
How long ago did it first appear?
Has it gone away a few times, before returning again and getting this big...or did this coming and going of the lump only occur once?
Customer: replied 9 years ago.


4 weeks ago. Yes he had it las year but very small, then it would go away. Could it be a bite from a spider?

Customer: replied 9 years ago.

4 weeks ago but not that size it was small, just about 4 to 5 days ago did it get this big. and just yesterday it started to bleed or discharge something.

Expert:  Dr. K replied 9 years ago.
It is unlikely that this is a spider bite, or other insect bite, since it has now been around for several weeks. There are a number of possibilities for something that looks that large. It could be an abscess (which is a pocket of pus under the skin). The doctor could determine this pretty quickly by putting a needle in it to aspirate out what is inside. If it is an abscess, the doctor would need to open it up, drain it out, and thoroughly clean it. Oral antibiotics would then be necessary to clear it up for good.
It could be a hematoma..which is a pocket of bleeding under the skin. The doctor could also determine this with a needle aspirate. Based on its behavior of getting very large over the last few days...I think that a hematoma is less likely. Also, hematomas usually stop getting bigger and then just go away.

Another possibility is that it is a tumor (either benign or malignant). Boxers are somewhat prone to cancerous tumors, and the history of it having appeared suddenly, then disappearing, and then reappearing again is a bit suspicious for an aggressive tumor called a mast cell tumor. These do need to be resected quickly.

Unfortunately, there is no way to know what a lump is definitively, unless it is removed surgically and sent in for biopsy. One way to try to find out is by doing a test called a fine needle aspirate. During this test, the vet places a needle inside the mass and pulls out some of the cells and other materials inside. This is then sprayed and smeared on a glass slide and is stained for viewing under a microscope. A pathologist can tell what a lump is 50% of the time with this test. The major benefit of this test is that it may give you an answer without having to put your dog under anesthesia.

Most people opt to surgically remove the lumps, even when benign, because this will give a definitive diagnosis, and the lump will then be gone if it is malignant (cancerous). Furthermore, many benign lumps do continue to get bigger and this can be cumbersome, unsightly, and sometimes uncomfortable for the dog.

I hope that this information is of help to you, and I wish you the best of luck with your dog. Please let me know if I can be of further assistance.

Dr. K