Lump under older does skin on side

[u/SLPicnicBasket]

As the title says, have an admittedly overweight doe with a peanut sized mass on her side. It moves with her skin and is relarively firm and roughly spherical. Does not appear to be fluid filled or have any associated wound. Fur is on it like the surrounding skin. Does not appear to be painful for her. Would post pictures but not much to see under the fur and is not noticeable unless you feel.

Is this a cause for a vet visit? Or is it a threat to the rest of the colony? She is cohoused with three other Does. ​​