Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips.
Abstract: Tear production was evaluated in 39 horses and 29 ponies using Schirmer tear test strips to determine whether diurnal or weekly fluctuations occur, whether location of strip placement has an effect, if values are the same for both eyes in an animal and whether sex, age, stabling vs. pasture and winter vs. summer had an effect. There was no test in which the raw score was less than 10 mm, although there were many occasions where tear wetting exceeded 35 mm. Analysis of the raw (continuous) scores by linear regression provided no evidence that signalment, housing or season or location of strip placement affected results. The distribution of tear test scores for a 'population' of eyes did not differ when the right eye was compared with the left eye or when the same eye was compared at different times on the same day. Individual test wetting values for opposing eyes measured at the same time, and also wetting values for the same eye measured at different times on the same day sometimes differed substantially. In winter maximum tear wetting exceeded 35 mm more frequently in the STT I than in the STT II even in housed horses and ponies, but there was no consistent significant difference. There appears to be wide variability in the STT I in normal horses and ponies.
Publication Date: 2003-09-03 PubMed ID: 12950657DOI: 10.1046/j.1463-5224.2003.00302.xGoogle Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research attempted to understand factors affecting tear production in horses and ponies using Schirmer tear test strips. It found that apart from some fluctuations in both an individual’s left and right eyes or in the same eye at different times of the day, there were no major impacts from age, gender, environment, season, and time of day on tear production.
Objective of the Research
- The study aimed to investigate tear production in normal horses and ponies, and whether various factors influenced it. These factors include daily and weekly fluctuations, strip placement, the similarity of values in both eyes of an animal, and the impacts of sex, age, environment (stabling vs. pasture), and season (winter vs. summer).
Methodology
- The research used Schirmer tear test strips to analyse tear production in 39 horses and 29 ponies. This involved measuring tear wetness, with scores below 10 mm and above 35 mm considered noteworthy.
- The analysis of the scores was done by linear regression to determine whether there were significant differences affected by factors such as signalment, housing, season, or strip placement.
Findings
- The study found that none of the considered factors significantly affected the tear test scores. This means that tear wetness in animals was not influenced by factors like age, sex, season, or the time of day.
- However, there were some fluctuations in the tear test scores. These fluctuations occurred between the left and right eyes of the same animal and in the same eye at different times of the day.
- In winter, maximum tear wetting was more prevalent in certain instances but there was no significant, consistent difference.
- The authors note that there is a high variability in the Schirmer Tear Test I in normal horses and ponies, meaning that tear production can significantly vary on an individual basis.
This indicates a need for further investigation into what might cause these individual variations and whether there might be other influencing factors that were not included in this study.
Cite This Article
APA
Beech J, Zappala RA, Smith G, Lindborg S.
(2003).
Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips.
Vet Ophthalmol, 6(3), 251-254.
https://doi.org/10.1046/j.1463-5224.2003.00302.x Publication
Researcher Affiliations
- Section of Medicine, University of Pennsylvania, New Bolton Center, Kennett Sq., PA, USA. jbeech3085@vet.upenn.edu
MeSH Terms
- Animals
- Circadian Rhythm
- Environment
- Female
- Horses / physiology
- Male
- Reagent Strips
- Reference Values
- Seasons
- Tears / metabolism
Citations
This article has been cited 12 times.- Faulkner J, Williams DL, Mueller K. Ophthalmology of clinically normal alpacas (Vicugna pacos) in the United Kingdom: a cross-sectional study. Vet Rec 2020 May 16;186(16):e7.
- Kovalcuka L, Boiko D, Williams DL. Tear production and intraocular pressure values in clinically normal eyes of whooper swans (Cygnus cygnus). Open Vet J 2018;8(3):335-339.
- Suyama Y, Matsuda K, Teshima T, Matsumoto H, Koyama H. The effect of environmental and biological factors on STT I and normal total tear protein concentration in Japanese black calves. J Vet Med Sci 2019 Jan 8;81(1):26-29.
- Trbolova A, Ghaffari MS. Results of the Schirmer tear test performed with open and closed eyes in clinically normal horses. Acta Vet Scand 2017 May 31;59(1):35.
- Chen Z, Shamsi FA, Li K, Huang Q, Al-Rajhi AA, Chaudhry IA, Wu K. Comparison of camel tear proteins between summer and winter. Mol Vis 2011 Feb 1;17:323-31.
- Allen R, Goodhead AD. A survey of ocular pathology in Warmblood horses in South Africa. Equine Vet J 2025 Jul;57(4):889-897.
- Pavel R, Ene I, Costea R. Exploring Lacrimal Gland Tear Production in Sheep under General Anesthesia: Examining the Potential Impact of Utilizing 1% Hyaluronic Acid Ophthalmic Gel. Life (Basel) 2024 Aug 20;14(8).
- Pe'er O, Ofri R, Sebbag L. Schirmer tear test-1 with open or closed eyelids: An evaluation in brachycephalic and nonbrachycephalic dogs. Vet Ophthalmol 2025 Jan;28(1):21-27.
- Kovalcuka L, Malniece A. Measurement of Tear Production and Intraocular Pressure in Clinically Conscious Normal Captive Red Deer (Cervus elaphus). Animals (Basel) 2024 Mar 19;14(6).
- Cinar H, Yanmaz LE, Buyukkaraca N, Kaya Z, Kosuncu M. Comparing the effects of intraocular pressure and tear production measurements in horses in two different environments: Horse stable and medical barn. Equine Vet J 2025 Jan;57(1):271-276.
- Aftab G, Rajaei SM, Faghihi H. Comparison of the Schirmer tear test I values after placement in ventral and dorsal conjunctival fornices in healthy cats. J Feline Med Surg 2018 Dec;20(12):1169-1172.
- Visser HE, Tofflemire KL, Love-Myers KR, Allbaugh RA, Ellinwood NM, Dees DD, Ben-Shlomo G, Whitley RD. Schirmer tear test I in dogs: results comparing placement in the ventral vs. dorsal conjunctival fornix. Vet Ophthalmol 2017 Nov;20(6):522-525.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
