Hmm...is there any redness or slight swelling near the base of the nails? Are her nails flaky looking, brittle or changing in color? Those are all symptoms of a fungal nailbed infection & the sneezing might be allergies (could be 2 different things). Doggies can get fungal infections in their nails just like humans can, particularly if their paws are frequently moist & open to the elements. It's also a common result when there is damage to a quick & bacteria has time to take up residency.
Good luck & whatever it is I hope she gets relief soon
