Prospective Ultrasonographic Evaluation of Adrenal Glands in a Population of Beagle Puppies and Functional Analysis of Basal Cortisol Levels in Blood

This study presents a prospective evaluation of adrenal gland development in a cohort of Beagle puppies, utilizing sonographic imaging and functional assessment of the basal serum cortisol concentrations. The objective was to characterize the growth patterns and physiological maturation of the adrenal glands in dogs between six and twelve months of age. Ten Beagle puppies from two litters, bred and maintained under standardized conditions at the Veterinary Teaching Hospital in Hannover, were included in the study. Serum cortisol levels were determined, and adrenal gland dimensions were measured using ultrasonography at regular intervals over a six-month observation period. The results demonstrated a significant growth trajectory of the adrenal glands, characterized by notable increases in both the longitudinal length and caudal pole diameter. No significant correlation was found between serum cortisol levels and adrenal gland size, indicating that the cortisol data primarily served to confirm the physiological function of the adrenal glands rather than to influence their size. The adrenal gland sizes mostly resembled those of adult animals; however, significant growth was observed between 6 and 12 months. In conclusion, the presence of small adrenal glands in young dogs with clinical suspicion should prompt further diagnostic testing or, at least, regular follow-up evaluations.