Lipomas (fatty tumors) are common in this breed so I would not get overly concerned right away about your findings. They are generally harmless.
Since there are lumps around the mammaries, you need to go ahead and see the vet for a fine needle aspiration. The vet will insert a fine needle into the lump and draw back some cells. Then they can tell you what you're dealing with.
In a lot of cases, it's just fatty tumors and they can be left alone. In other cases, further treatment is needed.
But, no matter what, go ahead and get in for that appointment!
Let me know if you have more questions.
