In this review, the structures of the ciliary body producing the aqueous humor and trabecular meshwork located in anterior cameral angle and playing an important role on the outward drainage of the aqueous humor, and the definition, classification, signs, diagnosis and treatment of glaucoma resulting from drainage failure of this fluid have been evaluated in the light of the current literatures. It has been evaluated in detail the surgical treatment techniques of glaucoma such as glaucoma filtration surgery (GFS, trabeculectomy) and anterior cameral shunt (ACS) used commonly nowadays and antiprolipherative agents that have an important contribution to prolonged success of GFS. It is suggested that the review may provide useful information to small animal practitioners and young researchers who has interest in the field of veterinary ocular diseases.