My 10-year-old Border Collie, Vinnie, started to develop fatty tumors a couple of years ago. I believe I know that a growth or tumor that is “hard” is dangerous, but if it can be moved around or “soft”, it’s just usually benign. I took him to the Vet to make sure (again), and he said, “It’s common for older dogs to develop fatty tumors, so these are nothing to worry about.”

But they seem to be getting bigger and bigger. Should I have them removed? Is it safe at his age? Are they causing him any pain?

Thank You.

Linda
San Diego, CA

There is no way to know whether a lump or mass is dangerous without sampling it. It is true that soft, mobile masses most often are benign and hard, anchored masses have a higher chance of being malignant. But there are ample exceptions to this rule. The simplest way to sample a mass is a technique called fine needle aspiration. It’s like a biopsy, only less invasive, less painful, and less expensive.

Fatty tumors also are called lipomas. I prefer the latter term because it doesn’t contain the scary T-word, and lipomas aren’t scary. They are just about the least dangerous type of mass that occurs in veterinary medicine. That’s a good thing, since they’re phenomenally common in older dogs.

I do not recommend removing lipomas unless they cause trouble–and they almost never cause trouble. They are not painful. They do not metastasize. They do sometimes make dogs look funny, but dogs are blessed with self esteem that is not based on something as superficial as physical appearance. Most lipomas are harmless.

Surgical excision of lipomas usually requires general anesthesia. The surgical sites may be painful for days. Post-operative complications such as hematomas (bleeding into the surgical site), seromas (oozing into the surgical site), and infection are not uncommon. Why risk these complications to remove a mass that isn’t causing any harm?

That said, lipomas in areas such as the armpits can grow large enough to interfere with mobility. It’s not common, but it happens–I have seen it twice in the last ten years. And, lipomas, like all masses, are most easily removed when they are small. There are instances when removing lipomas makes sense, but those instances are few and far between.

If your dog is like the overwhelming majority of his cohorts, the risks of removing the lipomas outweigh the benefits.

Here is a final thought. If your dog’s masses have not been sampled, they should be. Fine needle aspiration usually can distinguish a lipoma from a more dangerous mass instantaneously. Talk to your vet about this.