There are no specific drug therapies to treat instances of reverse sneezing. However, these episodes may be caused by another underlying condition that can predispose a dog to such episodes, states PetMD.
As outlined by PetMD, reverse sneezing is characterized by backwards motion of the head as the dog brings in air with lips sucking in. The purpose of this action is to remove irritants that may be lying behind the pet's nose and nasal passages. Reverse sneezing is typically the side effect of another condition, so treatment of the episodes of reverse sneezing lie in addressing the underlying condition. For puppies, a malformed palate may be a root cause. For adult dogs, the movement of the cilia lining the larynx may set off a reverse sneeze. The cilia function to remove irritants, but this function alone may not be sufficient. For instance, antihistamines can eliminate reactivity to allergens and thereby reduce reverse sneezing.