Aspectos macroscópicos e morfométricos das glândulas lacrimal e superficial da terceira pálpebra de cães (Canis familiares; LINNAEUS, 1758)

Tear film disorders in dogs can Key words: d o g s , t e a r f i l m , k e r a t o c o n j u n c t i v i t i s s i c c a , lacrimomimetics, lacrimostimulants, immunosuppressors. RESUMO

Reports of Toxocara canis ocular larva migrans are uncommon in animals, with only a few cases reported. Most reports involve larval migration into the retina and choroid, with parasitic invasion of the orbit reported only in experimental studies. This is the first clinical case of Toxocara canis infection in the retrobulbar region of a 10-year-old, cross-bred male dog presenting with unilateral orbital cellulitis. Ophthalmic signs included protrusion of the nictitating membrane, chemosis, exophthalmos and hypertropia. The parasite was diagnosed by histologic and parasitologic examination of orbital tissues, which were removed during enucleation.

A 5-year-old Brazilian Fila dog was presented with a history of vision loss, alopecia, and generalized depigmentation of the skin and hair. Clinical examination confirmed generalized depigmentation and pyodermitis. On ophthalmic examination there was depigmentation at the eyelid mucocutaneous junction, associated with anterior uveitis, and bilateral posterior synechia at 360 degrees. Both the complete blood count and skin scraping were normal. Skin biopsy showed histiocytary lichenoid interface dermatitis with an absence of pigment within the queratinocytes, and a moderate lymphomononuclear infiltrate and predominance of histiocytes in the papilar derma suggestive of uveodermatologic syndrome. Clinical management consisted of oral and topical administration of prednisone, associated with 1% indometacine eye drops. Methylprednisone was also used twice via the subconjunctival route, at an interval of 15 days. To prevent the development of secondary glaucoma due to posterior synechiae, dorzolamide and timolol eye drops were indicated. Both dermatologic and ophthalmic signs showed good improvement, vision was preserved, and some repigmentation of the skin and hair occurred.

Qualitative and quantitative abnormalities in primary components of the tear can alter the dynamics of the lacrimal film, compromising its function. Lipids, an aqueous fraction and mucoproteins constitute the lacrimal film. Keratoconjunctivitis sicca (KCS) is a disease commonly diagnosed in dogs. It is characterized by the deficiency of the aqueous fraction in the lacrimal film that results in dryness, inflammation of the conjunctive and cornea with progressive corneal illness and reduction of vision and pain. Due to the significant contribution of the third eyelid lacrimal gland to the production of the aqueous fraction of the lacrimal film, the removal of this gland when prolapsed is an important cause of iatrogenic keratoconjuctivitis sicca. This paper describes a clinical case of iatrogenic keratoconjuctivitis sicca in a 10 month-old Boston Terrier which was caused by the removal of the third eyelid lacrimal gland due to its prolapse.