Reduced tear production in three canine endocrinopathies

Area of Science:

• Veterinary Ophthalmology
• Endocrinology

Background:

• Keratoconjunctivitis sicca (KCS) is a common ocular condition in dogs.
• Previous reports suggest a link between endocrine disorders and KCS.

Purpose of the Study:

• To quantify tear production in dogs with diabetes mellitus, hypothyroidism, and hyperadrenocorticism.
• To compare tear production in these groups with healthy control dogs.
• To assess corneal sensitivity in diabetic dogs.

Main Methods:

• Schirmer tear test (STT) was performed on dogs with hyperadrenocorticism (n=16), diabetes (n=18), hypothyroidism (n=12), and 100 controls.
• Corneal sensitivity was measured in diabetic dogs using a Cochet Bonnet aesthesiometer.

Main Results:

• STT values were significantly lower in dogs with endocrinopathies (hypothyroidism: 12.3 mm/min, hyperadrenocorticism: 14.0 mm/min, diabetes: 12.3 mm/min) compared to controls (19.6 mm/min).
• Profound KCS (STT < 5 mm/min) was observed in only a few hypothyroid and diabetic dogs.
• Diabetic dogs exhibited significantly reduced corneal sensitivity.

Conclusions:

• Endocrinopathies like diabetes, hypothyroidism, and hyperadrenocorticism are associated with reduced tear production in dogs.
• Routine tear production assessment is recommended for dogs diagnosed with these conditions.
• Further research is needed to understand the mechanisms behind reduced tear production in these endocrine diseases.