We give my dog allergy medication to make her sleepy during oncoming thunderstorms...if need be you could use that too. Just a pill, or 1/2 a pill. People also use it for puppies that have an injury they shouldn't be jumping around with.

And aspirin is perfectly fine, although if used for too long i've heard of stomach ulcers and such. Did she rub her pad raw? Or maybe just sore...anyways keep us updated.