I suffer allergies to a few things, my furbabies included and I'm on an inhaled stereroid to help me breathe called advair.
I'm not sure how dog allergies work, but there are allergens all times of the year for humans depending on what you're allergic to.
There's a lot of mold during the winter so maybe she is suffering from that
I hope she feels better soon! Poor little Layla -- it stinks dealing w/allergies.