Today we will talk to you about one of the most common eye pathologies in dogs: dry eye disease or Keratoconjunctivitis Sicca.

Keratoconjunctivitis Sicca is an inflammatory disease of the ocular surface (cornea and conjunctiva) secondary to the deficiency of some of the phases of the tear film and which generates tear hyperosmolarity. This hyperosmolarity and increased friction will lead to secondary infections, dehydration and malnutrition of the cornea and conjunctiva and will increase the likelihood of corneal ulcerations. In turn, chronic inflammation of the ocular surface will also end up generating conjunctival hyperemia, hyperkeratinization and thickening of the corneal epithelium, corneal vascularization with increased migration of inflammatory cells and the deposition of pigment, lipids and calcium. The prognosis is usually favorable, although it will depend on the cause of the disease and whether effective treatment is implemented early and individualized for each patient.

There are two main classifications of Keratoconjunctivitis Sicca:

Qualitative: Pathological decrease in the lipid or mucoid components of the tear film. In this case, the lacrimal gland is functional and the hyperosmolarity of the tear is due to an increase in its evaporation. The cause of this type of Keratoconjunctivitis Sicca may be damage or acute/chronic inflammation in the meibomian glands and/or the goblet cells of the conjunctiva, such as in cases of infectious blepharitis, seborrheic dermatitis, etc.
Quantitative: Pathological decrease in the aqueous component of the tear film. In this case, hyperosmolarity is due to reduced secretion of the aqueous component under normal evaporation conditions. This is the most common initial presentation in dogs, although in most cases, a vicious circle is generated in which the other types of components of the tear film are also affected.

The causes of Quantitative Keratoconjunctivitis Sicca are varied, such as infectious diseases, endocrine diseases, systemic immune-mediated/autoimmune diseases, iatrogenic (surgical), etc. although the most common is localized and chronic immune-mediated inflammation of the lacrimal gland (immune-mediated adenitis). There are breeds of dogs and cats that are more predisposed, as we already mentioned in one of our previous posts on our social networks (Instagram and Linkedin), such as brachiocephalic breeds, West Highland White Terriers, Cocker Spaniels and American , etc.

The symptoms that may occur are: very characteristic mucous exudate, conjunctival hyperemia, opaque cornea, with neovascularization, corneal edema and ulceration, etc.

To reach a diagnosis, we will have to be attentive to the patient’s anamnesis and clinical history, perform a general and ophthalmoscopic examination, if we suspect systemic pathologies, general analytical and other complementary tests and followed by ophthalmological tests: Shirmer test, Fluorescein, Lysamine Green Test, TBUT (Tear Break-up Time), Impression Cytology and Osavet Test.

There are various types of systemic and topical medical treatments such as artificial tears (there is a wide variety), topical immunosuppressants, etc. and in most cases they can be applied together. Additionally, if there are secondary problems such as infections or corneal ulcers, these will also need to be treated. There are also surgical procedures such as parathyroid duct transposition, among others.

Another essential asset to help improve the symptoms of Keratoconjunctivitis Sicca, of which studies have already been carried out in dogs and which has others being carried out to demonstrate its effectiveness, will be supplementation with specific nutraceuticals such as Lacrimalis, rich in Omega-Fatty Acids. 3 that will improve the quality, stability and tear secretion, Lactoferrin with anti-inflammatory and antimicrobial properties on the ocular surface and antioxidants such as Vitamins E and C and the minerals Zinc and Copper.

From Dr+Vet Pet Care by Böthmen Pharma, we will present each of the different ophthalmological tests that we have mentioned little by little over the following weeks together with the Veterinary Ophthalmological Institute (IVO) so that you can learn more about them. lose!