Which preposition to use with spume

of Occurrences 5%

HORSE-SICKNESS Lying beside the road with outstretched neck and a spume of white froth on nose and muzzle are the horses of the 2nd Mounted Brigade; with bodies swollen by the decomposition that sets in so rapidly in this sun, and smelling to high heaven, are the fine young horses that came so gallantly through Kahe some ten days ago.

at Occurrences 1%

Quivering, throbbing with the tremendous effort, she dashed on, the water climbing her sides and lashing to spume at her stern.

Which preposition to use with  spume