Or it could be flea bites, allergy to fleas, food allergies, environmental allergeries, etc.
Any bumps and rashes are symptoms of these allergies.
The vagina is sensitive and closet to her thighs which usually manifests rashes due to food or environmental allergies.
It's not uncommon for dogs to be allergic to flea bites and fleas miagrate to the genitals.
Go to your local pet store and buy a topical ointment. Panolog is a good general ointment for any and all rashes (unless really bad and spread which indicates a staff infection that can get in their blood stream. See a vet for prescription oral meds to clear the staff infection)...Panalog contains nystatin-neomycin, sulphate-thiostrepton,triamcinolone)
Don't allow the rash, or any rash and bumps to spread out of hand. See a vet if it does.
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