Clinical Relationship between Cholestatic Disease and Pituitary-Dependent Hyperadrenocorticism in Dogs: A Retrospective Case Series

Abstract

Background: A high prevalence of cholestatic disease, including gallbladder mucocele (GBM), has been reported in dogs with naturally occurring pituitary-dependent hyperadrenocorticism (PDH).

Hypothesis/objectives: Differences exist in the clinical features of dogs with PDH and concurrent cholestatic disease, and also is the management of these dogs with trilostane.

Animals: Sixty-five client-owned dogs with naturally occurring PDH.

Methods: This was a retrospective, observational case series. Each dog was treated with trilostane for at least 3 months before the study, and had a good clinical response, as determined by owners. Statistical comparisons of clinical signs, results of routine blood tests, basal and post-ACTH cortisol concentration, and optimal trilostane dosage were made after dogs were separated into the following 3 groups by ultrasonographic imaging: normal on ultrasound (NOU) group, cholestasis group, and GBM group.

Results: The GBM group had more severe clinical signs and significantly different total serum cholesterol concentration and post-ACTH stimulation cortisol concentration at the time of diagnosis. Dogs that weighed <6 kg had a significantly higher prevalence of cholestatic disease than did the other dogs (P = .003). The optimal trilostane dosages for the GBM and cholestasis groups were 2.5 and 1.5 times the dosage of the NOU group, respectively (P < .001).

Conclusions and clinical importance: Gallbladder disease associated with cholestatic disease is correlated with PDH in dogs, in both its clinical features and drug management. These findings may be associated with hypercholesterolemia, unidentified genetic factors, and the hydrophobic nature of trilostane.

Keywords: Cholesterol; Female; Mucocele; Trilostane.

Figure 1

The box‐and‐whiskers plots comparing serum cortisol concentration (A) and required trilostane dosage (B) among 3 groups. The top end of each box represents the 75th percentile of data, and the bottom end represents the 25th percentile. The horizontal line through each box is the median. The whiskers on the top and bottom of the boxes indicate the highest data point still within 1.5 interquartile range (IQR) of the upper quartile, and the lowest data point still within 1.5 IQR of the lower quartile. Any data not included between whiskers are presented as outliers. NOU, normal on ultrasound; IQR, interquartile range. Statistically significant difference: *P = .03; **P < .001