Max had similar spots on his undercarriage last year and I took him to the vet twice. Two doctors deemed them an allergic reaction of some kind and gave us antibiotics that cleared them up right away.
I think it might be some kind of grass allergy, maybe Bermuda grass. Since I don't want Max on antibiotics several times a year, I tried organic coconut oil which has properties like Neosporin. It cleared the spots up. I like Nutiva brand, which I buy at the Vitamin Shoppe.
The spots do need to be taken of because they can turn into a staph infection.
Best wishes to Luma. She is super cute even when posing to show her spots.