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Dr. Kara
Dr. Kara, Veterinarian
Category: Dog
Satisfied Customers: 18169
Experience:  Over 20 years of experience as a veterinarian.
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Hi iv got a 14 year old staff, thats developed a brown spongy

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Hi iv got a 14 year old staff, that's developed a brown spongy growth on her front leg, it seems to have doubled in size other the last 3-4 days any advice would be appreciated thanks
Hello, my name isXXXXX and I have over 20 years of experience as a veterinarian. I'm sorry to hear that Storm has a brown, spongy growth on her front leg that has grown quickly over the last 3 to 4 days.

Does her bump look like the one in this link?

If her bump looks like that then it is possibly a sebaceous adenoma. These are very benign growths of the sebaceous (oil) glands and can be cream colored to reddish or black depending upon how irritated they get. They are very common on the head, neck, trunk and legs/feet. Once one pops up they seem to multiply. But really it's just if the dog has the genetic predisposition to form one then they will continue to get them. I tend to remove them if they break open or bother the dog as then they can get infected. Or if they are in a bad spot. They aren't really warts and aren't caused by a virus so don't respond to medication used to treat warts in people. They don't tend to increase in size quickly like her did, so this seems a little less likely.
Dogs can get viral warts but they occur in young dogs and are generally on the lips, mouth and sometimes the genital area. They would be very rare in an older dog.

Another likely cause is a benign growth called a histiocytoma. These growths pop up quickly, grow quickly for a month or so and then tend to regress and resolve on their own within 2 to 3 months. But they don't tend to grow quite as quickly as hers did. They are most common in young dogs on the face, ears and legs and paws. But older dogs can get them too and if they scratch them they may not resolve.
If the dog rubs them or scratches they will hang around longer or can get infected. You can use a drop of cortisone cream on them to reduce inflammation. If they are scratched open I would recommend an antibacterial ointment instead. And I would recommend an E-collar for her to try and stop her from scratching any more. If the bump doesn't resolve completely in 3 months it should be surgically removed as it is unlikely to go away on its own at that point and can lead to a secondary infection.

Another possibility is a tumor called a mast cell tumor. These have variable degrees of malignancy, some can be treated with just surgical removal, some are quite aggressive and will spread deep into tissue and to local lymph nodes. The only way to know for sure how malignant the tumor is is to remove it and have it biopsied. These tumors do tend to increase in size very quickly if bumped, because the cells they are made of contain histamine, so any trauma causes histamine release and swelling. This tumor seems very likely given your description.

Other tumors that this may be include a basal cell tumor but these are much less common in dogs then in people or a melanoma. These tend to be fairly benign behaving in the skin and respond to surgical removal. A plasma cell tumor is another possibility.

Of these tumors none resolve completely on their own except a histiocytoma. Mast cell tumors will change in size if they are bumped, and then go down slightly in size but never fully resolve on their own.

If you want to be absolutely certain of a diagnosis your veterinarian can perform a fine needle aspirate on the bump. He or she puts a tiny needle in the bump, draws cells out, and looks at the cells under the microscope to identify them.

In case this is a mast cell tumor you can give the antihistamine Benadryl (diphenhydramine only don't use the combination products with decongestants or acetaminophen as they can be toxic to dogs) at 1mg to 2mg per pound or two 25mg capsule per 30 to 50 pounds of body weight orally every 8 hours as needed, but for at least 5 to 7 days.
You can also very gently dab a little cortisone ointment on it. Do not rub as that will cause more histamine release.

Please let me know if you have any further questions.
Customer: replied 3 years ago.
Hello again I'm unable to see the photo which you recommended
Is there another link I can try , iv also found a photo of it on,jpg hopfully it's the same as what you mentioned thanks again
I'm sorry that you are unable to see the picture on the link I gave you, the link works for me.
The link that you gave me looks more like a button tumor or a histiocytoma.
Here's another link to see a sebaceous adenoma:

Customer: replied 3 years ago.
If it is the button tumour/histiocytoma what's the best course of action for me to take? Take her to the vets to get it removed or just leave it to heal by itself, iv got to be honest its about the same size as the one in the jpg i sent you
Honestly a button tumor (histiocytoma) in a dog her age is uncommon and it would be very rare for one to double is size over 3 to 4 days. I would be concerned that this is an atypical looking mast cell tumor.
If she were my pup I would aspirate the lump, look at the collected cells under the microscope and make sure it isn't a mast cell tumor.
I would recommend that you have it checked by her veterinarian because of the way it is behaving.
Dr. Kara and other Dog Specialists are ready to help you
Customer: replied 3 years ago.
Thanks for your help I will take her tomorrow afternoon get it checked out hopfully it's something easily treated cheers XXXXX XXXXX
You are very welcome. Please let me know how things go for her tomorrow, thanks, Dr. Kara.