Aloha! You're speaking to Dr. Michael Salkin I'm sorry for the delay in responding to you. Leuta's red and watery eyes may, indeed, be due to an allergic conjunctivitis but an infectious conjunctivitis, corneal disorders, misdirected eyelashes irritating the cornea (the clear window of the eye), infections of the lacrimal apparatus (dacryocystitis) and diseases of the globe of the eye (glaucoma, uveitis, e.g.) also need to considered. The proper manner in which to address such eyes is to have them carefully examined under magnification (an ophthalmologic exam) and then treated specifically predicated upon the findings of such an exam. Antihistamines aren't reliably effective in our allergic dogs in any event. If an allergy were suspected in Leuta's eyes, her vet is likely to dispense an ophthalmic ointment containing an antihistaminic glucocorticosteroid such as prednisone or dexamethasone. Please respond with further questions or concerns if you wish.