Poppy has pretty bad hayfever, she started with this last night not troubled her before. & its not constant but will last a few hours after her walk

her eyes are red & weepy & she is trying to paw at them.

i know that you can use piriton on dogs with hayfever, my vet recomended it, but im not sure of the dosage etc so dont want to risk this - unless anybody knows?

do any of you use an alternative natural remedy for hayfever & your dogs?