Epidemiological, clinical, and laboratory aspects in a case series of canine hyperadrenocorticism: 115 cases (2010-2014)

Abstract

ABSTRACT: Diseases’ clinical-epidemiological characterization assists in directing the diagnosis. The objective of this study was to describe epidemiological, clinical and laboratorial aspects of a case series of canine hyperadrenocorticism (HAC). One-hundred fifteen records of dogs diagnosed by the low dose dexamethasone suppression test and/or ACTH stimulation test were evaluated. Of the cases, 81.3% were HAC ACTH-dependent and 18.7% HAC ACTH-independent. Females were more affected, representing 69.3% of the cases. The mean age was 10.3±2.5 years and 64.9% were gonadectomized. Most of the patients were small size dogs, weighting less than 10kg (73.9%). The most frequent breeds were: Poodle (27%), Dachshund (17.4%), and Yorkshire Terrier (10.4%). The most frequent clinical manifestations were polyphagia (86%), polydipsia (82.6%), polyuria (80%), abdominal enlargement (82.6%), thin skin (79.1%), muscular weakness (78.3%) and panting (74.8%). However, eventually unusual HAC-associated signs would be present in some dogs in a more important way compared with the classic disease´s clinical signs. The CBC showed neutrophilia (66%), eosinopenia (58.3%) and lymphopenia (42.6%) as main hematological abnormalities. The most common findings in serum biochemistry were increased alkaline phosphatase activity (81.74%), increased ALT activity (62.6%), hypercholesterolemia (66%) and hypertriglyceridemia (54.7%). Urinalysis revealed hyposthenuria in 14.9% and isostenuria in 13.5%; besides proteinuria in 50% of the cases. Abdominal ultrasound showed bilateral adrenal hyperplasia (92.2%) with adrenal asymmetry in 20.8% of the cases, in addition to hepatomegaly (80.9%), biliary sludge (67.8%) and hepatic hyperechogenicity (47.8%). It was concluded that small size gonadectomized female dogs, mainly Poodles and Dachshunds, presented higher frequency in the population studied, and that the main changes observed in clinical and complementary tests were polyphagia, polyuria, polydipsia, abdominal enlargement, adrenal hyperplasia, increased phosphatase alkaline and hyperlipidemia. These results corroborated to a better disease characterization at Brazil. This work concluded that the population studied resembles the profile describe in European and North American epidemiologic studies, and that the HAC dog´s clinical picture looks similar worldwide.