Keywords
How to Cite
Abstract
In routine veterinary medicine, the lacrimal and nasolacrimal systems are associated with several ophthalmopathies. Understanding its physiology and improving specific diagnostic tests will help establish an assertive approach and avoid lacrimal and nasolacrimal disorders that cause damage to the ocular surface. This prospective study was conducted on 43 dogs treated at the Veterinary Ophthalmology Service and approved by the Ethics Committee for the Use of Animals under protocol number 5154141022. The study’s objective of this study was to evaluate lacrimal and nasolacrimal system findings in dogs treated byat an ophthalmology service, determine the frequency of lacrimal and nasolacrimal system disorders, and correlate the diagnosed changes with the patient’s main complaint. All dogs underwent a complete ophthalmic examination, emphasizing the lacrimal and nasolacrimal tests: the Schirmer tear test, tear film break-up test, tear crystallization test, and Jones test. The findings of these tests correlated with those of the ocular surface and the general condition of the dogs. Statistical analyses were performed using the Shapiro–Wilk test, Pearson’s chi-square test, and Student’s t test. The Student’s t test revealed that dogs with normal tear crystallization test scores had a significantly higher score (25.5 ± 4.94) than dogs with altered tear crystallization test scores (15.35 ± 6.64) (t (40) = 2.121, p = 0.004). Our findings suggest that quantitative and qualitative tear tests should be performed together and their interpretation depends on several factors, including ocular and systemic disorders.
References
Ali, M. J., Rehorek, S. J., & Paulsen, F. (2019). A major review on disorders of the animal lacrimal drainage systems: Evolutionary perspectives and comparisons with humans. Annals of Anatomy, 224, 102-112. http://doi.org/10.1016/j.aanat.2019.04.003. PMid:31071433.
Bertram, M., Allbaugh, R. A., Mochel, J. P., Peraza, J., Pade, L., & Sebbag, L. (2021). Influence of Schirmer strip wetness on volume absorbed, volume recovered, and total protein content in canine tears. Veterinary Ophthalmology, 24(4), 425-428. http://doi.org/10.1111/vop.12876. PMid:33720492.
Faghihi, H., & Rajaei, S. M. (2022). Tear film break-up time and Schirmer tear test in normal dogs: Effects of age, sex, reproductive status, skull type, and nasolacrimal duct patency. Veterinary Ophthalmology, 26(1, Suppl 1), 72-80. http://doi.org/10.1111/vop.13021. PMid:36039507.
Galera, P. D., & Cremonini, D. N. (2023). Nasolacrimal apparatus and tear film. In A. M. V. Safatle & P. D. Galera (Eds.), Veterinary Ophthalmology: Clinical and Surgical (pp.353-380). Payá.
Giuliano, E. (2021). Disease and surgery of the canine lacrymal secretory system. In G. Gelatt, B.C. Ben-shlomo, D. V. H. Gilger, T. J. Hendrix, T. J. Kern & C. E. Plummer (Eds.), Veterinary Ophthalmology (6th ed., v. 1, pp. 1008–1044). Blackwell Pub.
Haukoos, J. S., & Lewis, R. J. (2005). Advanced statistics: Bootstrapping confidence intervals for statistics with “difficult” distributions. Academic Emergency Medicine, 12(4), 360-365. http://doi.org/10.1197/j.aem.2004.11.018. PMid:15805329.
Labelle, A., & Labelle, P. (2023). Diagnosing corneal pigmentation in small animals. The Veterinary Clinics of North America. Small Animal Practice, 53(2), 339-352. http://doi.org/10.1016/j.cvsm.2022.11.001. PMid:36813389.
Malik, V., & Pandey, R. P. (2021). Ocular affections in dogs. Indian Journal of Canine Practice, 13(2), 63-70. http://doi.org/10.29005/IJCP.2021.13.2.61-70.
Marchini, L., Fachini, F. A., Rabelo, I. P., & Moraes, P. C. (2024). Oftalmophaties in 574 dogs of the breed Shih tzus attended at the Veterinary Hospital: retrospective study. Brazilian Animal Science, 25, 79326.
Masmali, A. M., Murphy, P. J., & Purslow, C. (2014). Development of a new grading scale for loom ferning. Contact Lens & Anterior Eye; the Journal of the British Contact Lens Association, 37(3), 178-184. http://doi.org/10.1016/j.clae.2013.09.011. PMid:24814055.
Meekins, J., Rankin, A., & Samuelson, D. A. (2021). Ophthalmic anatomy. In G. Gelatt, B.C. Ben-shlomo, D. V. H. Gilger, T. J. Hendrix, T. J. Kern & C. E. Plummer (Eds.), Veterinary ophthalmology (6th ed., v. 1, pp. 41-123). Blackwell Pub.
Naranjo, C., Fondevila, D., Leiva, M., Roura, X., & Peña, T. (2005). Characterization of lacrimal gland lesions and possible pathogenic mechanisms of keratoconjunctivitis sicca in dogs with leishmaniosis. Veterinary Parasitology, 133(1), 37-47. http://doi.org/10.1016/j.vetpar.2005.05.017. PMid:16023786.
Oriá, A. P., Raposo, A. C. S., Araújo, N. L. L., Lima, F. B., & Masmali, A. M. (2018). Tear ferning test in healthy dogs. Veterinary Ophthalmology, 21(4), 391-398. http://doi.org/10.1111/vop.12524. PMid:29111585.
Penaforte, K. M., Silva, E. S., Melo, S. N., Soares, P. H. A., Gonçalves, C. M. S., Ribeiro, R. A. N., Horta, M. A. P., Lélis, S. F., Silveira, C. G., Figueiredo, F. B., Teixeira-Neto, R. G., & Belo, V. S. (2024). Factors associated with adherence to the principles of responsible companion animal guardianship in a municipality in southeastern Brazil. Preventive Veterinary Medicine, 227, 1-7. http://doi.org/10.1016/j.prevetmed.2024.106207. PMid:38626595.
Pickett, J. P. (2019). Lacrimal apparatus. In C. L. Martin, J. P. Pickett & B. M. Spiess (Eds.), Ophthalmic disease in veterinary medicine (2nd ed., pp. 297-306). CRC Press, Taylor & Francis Group.
Reyneke, R. A., Richens, I. F., Buchanan, H., Davies, E. B., Sorrell, C., Ashmore, A., & Brennan, M. L. (2023). The use of theories, models, and frameworks to inform the uptake of evidence-based practices in veterinary medicine - a scoping review. Preventive Veterinary Medicine, 216, 105928. http://doi.org/10.1016/j.prevetmed.2023.105928. PMid:37224662.
Sahr, S., Dietrich, A., & Oechtering, G. (2021). Evaluating malformations of the lacrimal drainage system in brachycephalic dog breeds: A comparative computed tomography analysis. PLoS One, 16(9), e0257020. http://doi.org/10.1371/journal.pone.0257020. PMid:34492067.
Sebbag, L., & Mochel, J. P. (2020). An eye on the dog as the scientist’s best friend for translational research in ophthalmology: Focus on the ocular surface. Medicinal Research Reviews, 40(6), 2566. http://doi.org/10.1002/med.21716. PMid:32735080.
Sebbag, L., Silva, A. P., Santos, A., Raposo, A. C., & Oriá, A. P. (2022). An eye on the Shih Tzu dog: Ophthalmic examination findings and ocular surface diagnoses. Veterinary Ophthalmology, 26(1, Suppl 1), 59-71. http://doi.org/10.1111/vop.13022. PMid:36057776.
Tang, Y., Chang, H., Tsai, C., Chen, L., & Lin, D. P. (2020). Establishment of a tear ferning test protocol in the mouse model. Translational Vision Science & Technology, 9(13), 1. http://doi.org/10.1167/tvst.9.13.1. PMid:33344045.
Wegg, M. L. (2020). A retrospective evaluation of systemic and/or topical pilocarpine treatment for canine neurogenic dry eye: 11 cases. Veterinary Ophthalmology, 23(2), 341-346. http://doi.org/10.1111/vop.12731. PMid:31872935.
Woodham-Davies, S. (2020). Keratoconjunctivitis sicca in dogs. The Veterinary Nurse, 11(1), 19-23. http://doi.org/10.12968/vetn.2020.11.1.19.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2025 Lucas de Souza Viana, Diego Neves Vianna, Camila Cristina Rio Preto Martins de Sousa, Suzana de Souza Lima, Bruno Alberigi