title: Spontaneous Pathology and Routine Clinical Pathology Parameters in Aging Beagle Dogs: A Comparison With Adolescent and Young Adults.
abstract: AstraZeneca ran a bespoke study to generate age-matched clinical pathology and histopathology data from a cohort of Beagle dogs aged between 25 and 37 months to support the use of these older animals in routine preclinical toxicology studies. As the upper age range of Beagle dogs routinely used in toxicology studies does not normally exceed 24 months, there is an absence of appropriate age-matched historical control data. The generation of such data was crucial to understand whether age-related differences in spontaneous findings might confound the interpretation of toxicology study data. While the majority of the histopathology findings in all the older dogs occurred at a similar prevalence as those expected in young adult dogs (<24 months), a number of differences were observed in the thymus (involution), bone marrow (increased adiposity), testes (degenerative changes), and lung (fibrosis, pigment and alveolar hyperplasia) that could be misinterpreted as a test article effect. Minor differences in some clinical pathology values (hemoglobin, alkaline phosphatase, absolute reticulocytes) were of a small magnitude and considered unlikely to affect the interpretation of study data.
authors.affiliation: Drug Safety and Metabolism, AstraZeneca, Macclesfield, UK.
authors.forename: J
authors.initials: J
authors.lastname: Barnes
authors.affiliation: Drug Safety and Metabolism, AstraZeneca, Macclesfield, UK.
authors.forename: P
authors.initials: P
authors.lastname: Cotton
authors.affiliation: Drug Safety and Metabolism, AstraZeneca, Macclesfield, UK.
authors.forename: S
authors.initials: S
authors.lastname: Robinson
authors.affiliation: Drug Safety and Metabolism, AstraZeneca, Macclesfield, UK matt.jacobsen@astrazeneca.com.
authors.forename: M
authors.initials: M
authors.lastname: Jacobsen
mesh_terms: D000367:Age Factors; D000375:Aging / Q000473:pathology*; D000818:Animals; D015331:Cohort Studies; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D033162:Incidental Findings; D008297:Male; D013737:Testis / Q000473:pathology
keywords: aging; background lesions; beagle; clinical pathology; dog; histopathology; incidental findings; toxicology studies