Peer-reviewed veterinary case report
Tear tests in normal dogs and how age, sex, and skull shape affect
By Faghihi, Houman & Rajaei, Seyed Mehdi·Published in Veterinary ophthalmology·2023·Ophthalmology Section·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Tear film breakup time and Schirmer tear test in normal dogs: Effects of age, sex, reproductive status, skull type, and nasolacrimal duct patency.
- Species:
- dog
Plain-English summary
A study looked at tear production and tear film stability in 82 healthy adult dogs to see how factors like age, sex, and skull shape affected these measurements. It found that brachycephalic breeds (dogs with short noses) had lower tear film breakup times compared to other breeds, meaning their tears evaporated more quickly. Interestingly, these dogs also produced more tears to compensate for the quicker evaporation. Overall, the study suggests that while certain factors like age and reproductive status didn't impact tear production, the shape of the dog's skull did play a role.
People also search for: dog eye problems · brachycephalic dog tear production · why are my dog's eyes watery
Abstract
OBJECTIVE: The present study aimed to determine the effects of age, sex, reproductive status, skull type, and nasolacrimal duct (NLD) patency on tear production and tear film breakup time (TBUT) in normal dogs. ANIMALS STUDIED: The ophthalmic data of 82 healthy adult dogs were evaluated in this study. PROCEDURES: Age, sex, breed, and reproductive status were recorded. Schirmer tear test (STT) and TBUT were assessed in all dogs, and interferometry was available for the selected dogs. The Jones test was used to evaluate NLD patency. The cephalic index (CI) was calculated for each dog (skull width/skull length ×100). RESULTS: Mean (SD) values for the STT results for the right (OD) and left (OS) eyes were 20.6 (2.7) and 20.2 (2.7) mm/min, respectively. Mean (SD) TBUT values for OD and OS were 6.5 (2.5) and 6.1 (2.3) mm/min in all dogs, respectively. Sex and reproductive status had no significant effect on STT and TBUT (P > 0.05). Skull type significantly affected TBUT in both eyes (P = 0.01, P = 0.003), but had no effect on STT (P > 0.3). Age had no correlation with STT and TBUT in either eye (P > 0.05). STT and TBUT had no correlation in either eye (P > 0.2). NLD patency had no significant effect on STT or TBUT (P > 0.1). CONCLUSIONS: The results of this study showed lower TBUT values in brachycephalic breeds than in non-brachycephalic breeds. A compensatory increase in STT values was observed in dogs with low TBUT values.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/36039507/