Lump on the Rump

I just discovered a huge lump on my little 15ish yo yorkie/pom's rump...kind of off to side of tail on upper hip/toosh. I have noticed the last week or two, he's been holding his tail down more, which is what brought me to exploring deeper into it. I don't know if it developed fast, but I didn't notice it when giving him past toosh rubs [he loves them like a cat]. He has a lot of hair, so it could just be some thing I overlooked.

I will be calling vet after weekend, but I am having a hard time not letting my anxiety get the best of me. I had a ferret years ago that had a lump on the rump and it turned out to just be a harmless mass, which the vet cut open and rinsed out. It never returned and he lived a full life. Due to age here, I don't know if I can be as hopeful it's just a harmless mass, but even if it is...he has a heart murmur and I've had a couple different vets express they won't risk him in surgery [which I am not disagreeing with].

Does anyone have any experience here or can help me have kind of an idea of what to expect?

Sending healing vibes. My neighbor's lab had a lump on his rear; the vet said it wasn't just a mass that would eventually open up and drain on it's own. After about 3 weeks, it started to drain. My neighbor had to put peroxide on it to keep clean and all is well.

Did you get it looked at? Sounds like it's an anal gland issue from what you're describing. Is it painful?

I hope all would be well for your mature dog. Sending good vibes.

Sorry didn't see this. Yeah it's not low enough to be gland area. Vet thinks it's a cyst and wasn't overly concerned.

So glad to hear this. Thanks for updating us.