Doxycycline Hyclate is a broad spectrum antibiotic that is a member of the Tetracycline family.It is used to fight bacterial infections in dogs and cats.It is also used to treat many different bacterial infections including Leptospirosis, Toxoplasmosis, Mycoplasma, Psittacosis and Tick Borne Disease including Ehrlichiosis, Lyme disease Rocky Mountain Spotted Fever and other Protozoa