Postnatal development of canine axial globe length measured by B-scan ultrasonography


Address communications to: S. M. Petersen-Jones Tel.: (517) 353-3278 Fax: (517) 355-5164 e-mail:


Objective  The objectives of this study were to document the development of axial globe length (AGL) in normal mesocephalic cross-bred dogs between 2 and 52 weeks of age, to determine a relationship between AGL and age, and derive an equation to predict AGL in normal mesocephalic cross-bred dogs.

Animals studied and procedure  The AGL of twenty normal mesocephalic cross-bred dogs was measured at 12 time points from 2 to 52 weeks of age using B-scan ultrasonography.

Results  The mean (± SEM) AGL increased from 12.65 mm (± 0.18) at 2 weeks of age to 19.52 mm (± 0.18) at 52 weeks of age. The correlation between AGL and age was evaluated by fitting possible variables to a regression pattern. A linear model of natural logarithmic-transformed value of AGL (mm) and age (week) was established. Side (left or right eye) and gender did not correlate with development of AGL.

Conclusions  A reverse transformation of the formula can be used to predict AGL in mesocephalic cross-bred dogs: AGL = 10.847 * age in weeks 0.1653.