Abstract
A 12-year-old male miniature dachshund, weighing 6.2 kg, presented with a 1-year history of pigmentation and alopecia on the nasal bridge, abdominal distention, alopecia and desquamation on the trunk, alopecia and skin flare on a tarsal joint, and a 1-month history of polyuria and polydipsia (PU/PD, 192 ml/kg/day). The adrenocorticotrophic hormone (ACTH) stimulation test showed a pre cortisol level of 12.1 μg/dl and a post level of 68.4 μg/dl. Computed tomography revealed a 3-mm pituitary gland and bilateral adrenal gland enlargement (right, 16 mm; left, 13 mm). The diagnosis was pituitary-dependent hyperadrenocorticism. The pituitary region was irradiated in three fractions once a week for a total of 18 Gy. Hair growth and water consumption (167 ml/kg/day) improved slightly when radiotherapy was completed. No acute radiation side effects were detected. After completion of radiotherapy, the owner reported that the PU/PD improved gradually (day 85, 138 ml/kg/day; day 157, 94 ml/kg/day; and day 388, 85 ml/kg/day). On day 157, the lesion on the nasal bridge improved, and on day 388, the hair coat was normalized. The ACTH stimulation test showed a pre cortisol level of 10.7 μg/dl and a post level of 64.0 μg/dl on day 85, and a pre level of 6.3 μg/dl and a post level of 36.1 μg/dl on day 410. Hypofractionated low-total-dose radiotherapy was not effective immediately, unlike medical management, but it may be useful for controlling some clinical symptoms without radiation side effects.
