Chapter 4 Lacrimal System
Conditions of the nasolacrimal system affect the lacrimal secretions, particularly the aqueous phase of the tear film secreted by the lacrimal and third eyelid glands and the lipid secretions of the meibomian gland. Keratoconjunctivitis sicca (KCS) is undoubtedly the most important disease of lacrimal secretion that occurs commonly in dogs of numerous breeds; the incidence in cats is much lower. For a variety of reasons, the majority of problems involving nasolacrimal drainage manifest as limited tear drainage, often resulting in epiphora.
Figure 4-1 A-B A, Chronic KCS has caused corneal scarring, neovascularization, and increased mucous discharge. Note the mucopurulent discharge adhering to the eyelids and cornea. B, the eye after it was cleaned of discharge.
Figure 4-2 Mucopurulent discharge adherent to the eyelids and cornea and corneal neovascularization as a result of KCS.
Figure 4-3 KCS in an Australian heeler. Mucopurulent discharge and corneal neovascularization are marked.
Figure 4-4 KCS in a shih tzu. Mucopurulent discharge and corneal edema and vascularization are present.
Figure 4-5 Chronic KCS in a Lhasa apso. Periocular dermatitis is present, and crusted discharge is attached to the eyelid cilia. Mucopurulent discharge adheres to the corneal surface.