Age-Related Variations of Corneal Sensitivity in Puppies Beagle Dogs - Original Report - Open Access

Sep 28, 2026

Objective: assess the evolution of corneal sensitivity in healthy beagle puppies during the first weeks of life, compare findings with adult corneal sensitivity, and identify the age when adult levels are reached. Animals studied: twelve puppies and five adult females. Corneal touch threshold (CTT) was measured weekly (puppies, 2–7 weeks) and in mothers using a Cochet–Bonnet esthesiometer, with humidity and temperature recorded.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages5

Reading Time13 min

AccessFree to download

Abstract

Objective

Animals Studied

Procedures

Results

Conclusions

Introduction

Corneal sensitivity and innervation

Corneal sensitivity measurement history

Corneal Touch Threshold (CTT) and influencing factors

Veterinary Ophthalmology ORIGINAL REPORT OPEN ACCESS Age-Related Variations of Corneal Sensitivity in Puppies Beagle Dogs Sabine Chahory1 | Célia Maringue2 | Pierre Huiban3 | Loïc Desquilbet4 1Ecole Nationale Vétérinaire d'Alfort, CHUVA, Unité d'Ophtalmologie, Maisons-Alfort, France | 2Ophtavet, Paris, France | 3Mon véto Beynes, Centre Commercial de la Petite Mauldre, Beynes, France | 4Ecole Nationale Vétérinaire d'Alfort, IMRB, Maisons-Alfort, France Correspondence: Sabine Chahory ([sabine.chahory@vet-alfort.fr](sabine.chahory@vet-alfort.fr)) Received: 16 June 2024 | Revised: 5 February 2025 | Accepted: 8 February 2025 Keywords: aging | cornea | corneal esthesiometry | corneal sensitivity | dog ABSTRACT Objective: To evaluate the evolution of corneal sensitivity in healthy beagle puppies during the first weeks of life, compare these results with adult corneal sensitivity, and determine the age at which adult corneal sensitivity levels are reached. Animals Studied: Twelve puppies and five adult females. Procedures: Corneal sensitivity was assessed in puppies weekly from 2 to 7 weeks of age and in their mothers by measuring the corneal touch threshold (CTT) in the central cornea using a Cochet–Bonnet esthesiometer. Hygrometric and temperature measurements were recorded throughout the study period. Results: In puppies, esthesiometry indicated a progressive decrease in corneal sensitivity with age. Sensitivity was higher between 2 and 4 weeks, which stabilized between 5 and 7 weeks, with a median CTT values of 0.5, 0.5, 0.8, 1.4, 1.2, and 1.4 g/mm2 at 2, 3, 4, 5, 6, and 7 weeks, respectively. The median CTT in puppies reached the adult median value (1.4 g/mm2) at 5 weeks. The median CTT at 2 weeks was significantly different from the median CTT at 7 weeks (0.5 vs. 1.4 g/mm2). Humidity and temperature were not significantly associated with corneal sensitivity in adults. Conclusions: In this study, corneal sensitivity in beagle puppies was higher during the first 3 weeks of life compared to 7 weeks. During this early period, puppies exhibited corneal sensitivity levels exceeding those of adults, which subsequently decreased to adult-equivalent values between 5 and 7 weeks of age. 1 | Introduction The cornea is the most sensitive tissue in the body, responding to sensations such as touch, pain, and cold [1] . Corneal sensitivity is mediated by the central nervous system and serves as a primary protective mechanism for the ocular surface through the blink reflex [1–3] . The ophthalmic division of the fifth cranial (trigeminal) nerve forms the posterior ciliary nerves, which are responsible for corneal innervation. Near the cornea, a superficial meshwork, known as the limbal plexus, branches into numerous nerve fibers that penetrate the cornea, dividing into stromal and subepithelial nerve plexuses. During development, the subepithelial plexus produces bundles that rise to the epithelium in ascending branches. These branches are activated by corneal stimuli through mechanonociceptors, polymodal nociceptors, or cold receptors [1–4]. Corneal innervation provides corneal sensitivity, participates in eyelid closure, and liberates neurotrophic factors. These key roles are crucial for preserving corneal function, avoiding epithelial cell impairment, corneal transparency, and healing ability [2]. Corneal denervation leads to morphological and physiological disturbances, including epithelial cell swelling, desquamation, and surface microvillus loss, resulting in epithelial defects [5]. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2025 The Author(s). Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologis

FAQs

What was the study objective regarding corneal sensitivity in beagle puppies?

To evaluate how corneal sensitivity changes during the first weeks of life in healthy beagle puppies, compare it with adult sensitivity, and determine when adult levels are reached.

How was corneal sensitivity measured in the puppies and adult females?

By measuring the corneal touch threshold (CTT) in the central cornea using a Cochet–Bonnet esthesiometer. Puppies were assessed weekly from 2 to 7 weeks of age, and mothers were assessed during the study period.

What did the results show about CTT changes with age in puppies?

Esthesiometry showed a progressive decrease in corneal sensitivity with age. Sensitivity was higher from 2 to 4 weeks and stabilized between 5 and 7 weeks, with puppies reaching the adult median CTT value at 5 weeks.

Sep 28, 2026

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