Doxycycline is a broad spectrum antibiotic that is a member of the tetracycline family. It is used to fight bacterial infections in dogs and cats. Doxycycline is used to treat many different bacterial infections including, leptospirosis, toxoplasmosis, mycoplasma, psittacosis, and tick borne diseases including Lyme disease, ehrlichiosis, and Rocky Mountain spotted fever.**We directly source prescription medications from manufacturers and wholesale distributors registered with the FDA and licensed by applicable state boards. Guaranteed genuine, and where applicable, backed by the manufacturer.**