Abstract
We performed MRI scanning of the adrenal glands together with both clinicopathologic analysis and a skin biopsy in Pomeranians with non-illness, generalized alopecia. Fifty-one Pomeranians with the alopecia were included in this study, all of which had a brachycephalic type. Laboratory tests carried out on selected cases revealed slight elevations of several tests PCV, ALT, AST, ALP, and blood glucose, a slightly exaggerated response to ACTH stimulation test, and in some cases, inadequate suppression against low-dose dexamethasone. All animals showed a normal response to TSH administration. All 18 dogs on which we performed skin biopsies showed mild epidermal thinning, hyperkeratosis, follicular atrophy, and thinning of the subcutaneous adipose tissue. MRI scanning was performed in 14 of the affected dogs and 3 healthy control Pomeranians. Median length, width, and thickness of the adrenal gland in affected dogs were not different from those in control dogs, and no abnormality of the pituitary gland was found. Based on these findings, it is considered that abnormal adrenal steroidogenesis associated with adrenal hyperplasia is not an acceptable pathogenesis of this condition. It is hypothesized that the affected dogs seem to have a breed- and/or family-specific, physiological hormonal constitution that may lead to alopecia, rather than suffering from a functional anomaly of the adrenal gland.
