If it's just one foot, then it sounds like she's got something in there. A sticker, a tiny piece of grass seed or even a small piece of glass. Inspect her foot thoroughly. Top and bottom, in between the toes, up close and personal (use a magnifying glass).
If it's more than one foot, then it's likely allergies.
Wash her foot in mild dog shampoo. If it continues through the morning, then I'd call the vet.
If it's more than one foot, then it's likely allergies.
Wash her foot in mild dog shampoo. If it continues through the morning, then I'd call the vet.