Addition of cabergoline to trilostane treatment for dogs with pituitary-dependent hypercortisolism

STEFANIA GOLINELLI, FEDERICO FRACASSI, ÁLAN GOMES PÖPPL, VIVIANI DE MARCO, KYOUNG WON SEO, EDWARD C. FELDMAN; MICELI DD

Congreso; ECVIM CONGRESS; 2023

Trilostane(T) is usually effective in controlling the hypercortisolemic state in canine pituitary-dependent hypercortisolism (PDH), however, its effect on pituitary tumor (PT) function and growth has not been reported. Cabergoline (C), a dopamine agonist,is a potential “pituitary-targeting”drug.This study aimed to evaluate the addition of cabergoline totrilostane in controlling PDH’s clinical signs and/or blocking growth or even reducing the size of PTs.This prospective, controlled, multicenter study included 25 dogs with PDH (PT height [PTh] 12 mm). Thirteen dogs (TC group; TCg) were treated with Tmedian 0.5 mg/Kg (minimum 0.3-maximum 3.2)and C (23 mcg/Kg q48h) (TC group, TCg) and 12 dogs with onlyT(T group, Tg) for at least 6 months. Each dog underwent a pituitary CT scan at the beginning (T0) and the end of the study (T180-T365); pituitary/brain ratio (PBr) was calculated from each scan. Each dog was monitored at T30 (days), T60, T120, T180, and T365 with a clinical evaluation (standardized questionnaire,higher scores were associated with worst PDH clinical control), urine specific gravity (USG), cortisol (prepill or ACTH stimulation test) and endogenous ACTH (eACTH)measurement. Results of the questionnaire, USG, eACTH, PTh, and PBrwere not significantly different between TCg and Tg at any time point. Questionnairescores were significantly higher (P=0.0101) at T30 versus T365 in the Tg. Urine specific gravity was significantly lower (P=0.0312) at T0 versus T365 in the Tg. The PBr was significantly higher (P=0.044) at T0 in comparison with T365 in the Tg group. In the TCg,PThwas smaller in 4/12 0.5 mm (0.04-1.5);PTh did not change in 2/12; PTh increased in 6/12 dogs2.15 mm (0.25-5.2); andone dog died before the end of the study. In the Tg,PThwas smaller in 5/120.27 mm (0.05-1.3), was not visualized at either T0 or T365 in one, and it increased in 6/12 dogs1.55 mm (0.24-5.7). In TCgthe PBrreduced in 4/12dogs 0.07 (0.01-0.13)and increased in 8/12 dogs0.08 (0.06-0.43). In the Tg,the PBr reduced in 3/120.02 (0.01-0.03), did not change in 3/12, and increased in 6/12 dogs0.15 (0.06-0.35). In conclusion, the combination of trilostane and cabergoline treatment does not improve the control of PDH’s clinical signs in comparison with trilostane treatment alone. Function and size of PT is not influenced by the addition of cabergoline to trilostane treatment of canine PDH.