Strange bulge/nodule on nipple of dog

Question

My female dog, aged 12 years, developed a bulge on her nipple about 3 years back.

We showed it to the local vet who said (by just seeing it and without any tests) that it was the reaction of her medication Gardinal 30.

Then we took her to a larger hospital who did X-ray and everything and said it was stage 4 cancer and she had few months or a year to live. They refused to surgically remove it as this would have killed her in their opinion.

That was three years ago, and she's still hale and hearty.

We suspect it was wrong diagnosis, as she should not have survived so well for so long after cancer.

Anyone has any ideas what it is? I am asking because she is developing another bulge near it, and I'd like to get rid of it if I can.

Answer 1

Full disclosure: I'm neither a vet nor a medical professional, but I do work in the manufacturing of medical devices and learned some medical knowledge for my job.

The images clearly show the bulge with an uneven, ridged surface. That is a strong indicator for a malignant tumor, so I have no reason to doubt the diagnosis of your vet. Benign tumors like lipoma tend to have a smooth surface and a clearly defined margin, which means they feel encapsulated and can be nudged around under the skin. You can read about benign vs. malignant tumors on Wikipedia.

If you doubt your vet you can and should get a second opinion from a different vet.

Whether or not this tumor could have been surgically removed is outside of my expertise. But there are 2 major problem with malignant tumors:

1. They usually don't have a clearly defined margin, but meld and mix with the healthy tissue around them.
2. You have to remove the entire tumor without cutting into it, because if tumor cells get into the bloodstream they will metastasize. That means you have to cut a wide margin around the tumor, removing a lot of healthy tissue to avoid the risk of metastasizing.

That could have been one reason why the vet clinic didn't want to operate.

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The original prognosis was that "she had few months or a year to live". She was 9 years old at that time. The cell division rate of all cells (including cancer) slows down with age, so a younger dog with the same tumor might have died in the past 3 years. Cancer can be unpredictable like that. The growth rate depends on many factors including the food you eat and how physically active you are.

I think nowadays doctors aren't supposed to voice any prognosis in terms of months or years anymore because too many patients and loved ones where devastated when the end came sooner or suffering went on for so much longer than predicted.

My personal opinion is that you should feel extremely lucky that you've got so much more time with your dog. I do advice against an operation because at 13 years she is a senior who might face complications like circulatory problems or slow wound healing and (as mentioned above) if it's a malignant tumor and it isn't removed entirely in one piece, the operation will probably cause more metastases.