A few days ago I saw a 10 year old husky for a routine check-up and vaccines. She is unspayed and has been overall healthy for most of her life. During the exam I noticed a firm, irregular mass in her mammary chain, and with a second look I found a smaller mass nearby. I called and talked to the owners, and they had not noticed these swellings, and were surprised when I pointed them out. We had also seen this dog in May for unrelated issues and had not noticed the masses then either. So in a 2-3 month period these lumps had developed.
In an older female dog who had never been spayed the most likely possibility is mammary gland cancer. This form of cancer can potentially be as bad and as malignant as breast cancer in humans. We took some chest x-rays to make sure there were no obvious metastases in the lungs, and when those were clear I talked to the owners about a partial mastectomy. In cases like this it's important to move quickly, removing the masses as soon as possible to minimize the likelihood of them spreading. Leave them too long and you're almost assured of metastasis. There are sometimes benign masses as well as other types of cancer, but there is no way to tell for certainty without removing them and sending them for a pathologist review.
Today she came in to have the surgery done. We did our normal preanesthetic evaluation, blood tests, and so on, and considered her generally healthy. We placed her catheter, induced her, and began doing the surgical shave and prep of the site. As we were shaving we noticed another small mass under the skin on the same site but several centimeters away from the largest mass. Further shaving showed an fourth mass close to the newest one but on the other side of the abdomen, so in a completely different mammary chain. This concerned me greatly, as we had masses developing in very separate locations from the largest lesion. I had checked all of the mammary regions earlier in the week, so it surprised me to find more masses, even if they were small. Did I miss them because they were small and she has thick fur? Did they start to grow in a few days time? Unfortunately I couldn't say for sure.
I called the owner before we went to surgery and presented them with the new information. I discussed the options, neither of which were good. The primary reason for doing the surgery was to remove the masses before there was further spread. We didn't know how quickly it was spreading, as the lumps I found could have started growing two months ago or in the last couple of weeks. Since there were new lumps in different locations, there was already spread. However, we could proceed with the surgery and do a more radical procedure, basically a double mastectomy. This is a radical, extensive, and painful surgery, and one not to be undertaken lightly. The odds were good that spread in the bloodstream was already happening, but there was no way to tell for certain. So should we do a more complicated surgery and roll the dice, hoping for the best? Or should we realize that metastasis may already be happening, it was too late to prevent it, and save her a painful and potentially long recovery?
This was a very difficult decision for the owner. Honestly, I was on the fence myself, though leaning towards not doing the surgery as I was worried that it wouldn't help her in the long run. But my job is to give the client enough information for them to make an informed decision. I can never make the decision for them. And if it was my own dog I would have had an equally hard time making up my mind.
In the end the owner decided to forgo the surgery and observe her, giving her the best quality of life they can. I can't say that this was the wrong decision. Sometimes in medicine there is not a straightforward choice, only difficult ones.