Bilateral Basal Nuclei Vacuolar Lesions: A Novel and Emerging Potential Background Finding in Beagle Dogs

In this case presentation, the speaker and co-authors represented a group of scientists engaged in a cross-institutional precompetitive working group focused on elucidating a novel background change in the basal nuclei of Beagle dogs. The group's ongoing efforts since first publication of the lesion in 2024 enabled further characterization of the lesion and revealed additional incidences in control animals. The characterization, including newly discovered lesion features, and terminology of the condition were outlined and suggestions for interpretation in nonclinical toxicity studies were given.