J Vet Sci.  2023 Mar;24(2):e32. 10.4142/jvs.22237.

Association of serum 25-hydroxyvitamin D concentrations with Schirmer tear test 1 and tear film breakup time in dogs

• Kim Y
• Kang S
• Seo K

• KMID: 2541339
• DOI: http://doi.org/10.4142/jvs.22237

Abstract

Background
The association between vitamin D and canine keratoconjunctivitis sicca (KCS) has not been investigated in dogs.
Objectives
To investigate the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with Schirmer tear test 1 (STT-1) and tear film breakup time (TFBUT) in dogs.
Methods
Sixty-one clinically healthy, client-owned dogs were enrolled. STT-1 and TFBUT were measured in 122 (61dogs) and 82 (41 dogs out of total 61 dogs) eyes, respectively. Serum 25(OH)D concentrations were evaluated by quantitative chemiluminescent immunoassay. The dogs were classified into 6 groups according to the evaluations (STT-1: group 1, normal [≥ 15 mm/min] in both eyes; group 2, normal in one eye and abnormal [< 15 mm/min] in the fellow eye; group 3, abnormal in both eyes; TFBUT: group 4, normal [≥ 20 sec] in both eyes; group 5, normal in one eye and abnormal [< 20 sec] in the fellow eye; group 6, abnormal in both eyes).
Results
STT-1 was positively correlated with TFBUT (p < 0.001). Among the STT-1 groups, the mean serum 25(OH)D concentration in group 1 was significantly higher than in groups 2 and 3 with positive correlation (p < 0.001). However, there were no significant differences among the TFBUT groups 4, 5, and 6.
Conclusions
In dogs, it was found that serum 25(OH)D concentrations had a greater effect on quantitative KCS than qualitative KCS. Therefore, it is considered that measurement of serum 25(OH)D concentration could be included in the diagnostic tests in canine quantitative KCS patients.

Keyword

Canine; dry eye; dry eye test; keratoconjunctivitis sicca; vitamin D