Outcomes of transsphenoidal surgery in 34 small dogs with pituitary-dependent hypercortisolism.

OBJECTIVE

This study aimed to evaluate the clinical outcomes of transsphenoidal surgery (TSS) in dogs weighing < 15 kg with pituitary-dependent hypercortisolism (PDH).

ANIMALS: The study included 34 dogs, each weighing < 15 kg, diagnosed with PDH, and undergoing TSS at our facility between 1999 and 2021.

PROCEDURE: Postoperative assessments included fatal complications within 4 wk, the extent of mass resection, the duration of central diabetes insipidus, long-term survival, and duration of remission.

RESULTS

Five dogs died within 4 wk after TSS. Complete resections were completed in 28 dogs, whereas 6 dogs underwent partial resection. Factors associated with partial resection included a higher pituitary-to-brain ratio (odds ratio: 112 705.8; P = 0.014). The median duration of central diabetes insipidus after TSS was 9.5 d. The median long-term postoperative survival was 1228 d. The estimated censored survival rates were 83 and 69% at 1 and 2 y postoperatively, respectively. Recurrence of PDH was observed in 2 dogs, with a median postoperative remission duration of 1188 d. Estimated recurrence-free rates were 90 and 90% at 1 and 2 y postoperatively, respectively.

CONCLUSION AND CLINICAL RELEVANCE: Transsphenoidal surgery is an effective treatment for PDH in dogs weighing < 15 kg, particularly when the pituitary gland is small.