Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

188 •DOG OWNER’S HOME VETERINARY HANDBOOK
see how much of the strip is wetted. Normally the strip should be wet to a distance
of 20mm. In dogs with dry eye, the strip wets less than 10mm (often less
than 5mm).
Treatment: For many years, the frequent application of artificial tears was
the only treatment available for dry eye. But FDA approval of ophthalmic
cyclosporin has revolutionized treatment and greatly improved results.
Cyclosporin is an immunosuppressive drug that reverses immune-mediated
destruction of the lacrimal glands.
Cyclosporin ointment is applied to the surface of the involved eye. The
frequency of application must be determined by your veterinarian. The effect
is not immediate. Artificial tears and topical antibiotics should be continued
until the Schirmer tear test indicates that the volume of tears is adequate.
Treatment is life-long. Interrupting cyclosporin for as little as 24 hours
causes symptoms to reappear in 90 percent of dogs. This can be reversed by
resuming treatment.
When damage to the lacrimal glands leaves little or no functioning tissue,
cyclosporin is not likely to be effective. Artificial tears (drops and ointments)
prescribed by your veterinarian must then be instilled into the dog’s eyes several
times a day for life. Ointments are less expensive and do not need to be
applied as frequently as drops. Saline drops should not be used because they
aggravate the problem by washing away the lipid layer of the tear film.
A topical mucolytic agent containing acetylcystine may be recommended
to reduce heavy mucus accumulation. Topical antibiotics are indicated whenever
the mucus discharge becomes purulent. Topical corticosteroids may be
prescribed by your veterinarian in some circumstances to decrease inflammation.
In the presence of corneal ulceration, corticosteroids are contraindicated
because they predispose a dog to rupture of the cornea.
Surgical treatment can be considered as a last resort when medical management
fails. The operation involves transplanting the duct of the parotid
salivary gland up into the corner of the eye. The saliva takes the place of the
tears. The operation has several significant disadvantages. One is that the
volume of tears may be more than the drainage system can handle. This can
result in a watery eye and the accumulation of mineral deposits on the cornea
and face.
EPIPHORA (WATERY EYE)
There are many conditions in which a watery or mucus discharge overflows
the eyes and runs down the face. With a severe watery eye there is constant
wetness and the skin may become inflamed and infected, adding to the dog’s
unsightly appearance and physical discomfort.
Epiphora is primarily a cosmetic problem unless it causes inflammation or
is a symptom of a painful eye. For example, entropion, conjunctivitis, foreign
bodies, corneal ulcers, anterior uveitis, and acute glaucoma are all accompanied