Frequency of Endocrinopathies and Characteristics of Affected Dogs and Cats in Southern Brazil (2004-2014)

Abstract

Background: The increase in the life expectancy of dogs and cats in recent decades has heightened the incidence of aging-associated diseases. Among such diseases, endocrinopathies, such as obesity, stand out. In addition, there exists a lack of professionals with expertise in this area. Therefore, proper knowledge of the characteristics of patients affected by endocrinopathies as well as the frequency of these diseases aid in the recognition of endocrine syndromes in the general population. Thus, the aim of this study was to conduct a retrospective analysis of medical charts of dogs and cats compiled by a Division of Endocrinology in southern Brazil during a 10-year period.Materials, Methods & Results: An epidemiological survey of the medical charts of 1,400 dogs and cats compiled by a Division of Endocrinology between 2004 and 2014 was performed. The diagnostic data based on laboratory and hormone tests and on ultrasound scans were used as gold standard. The data were tabulated using Excel for Windows for the stratified analysis of the diagnoses. The major diseases (93.4% of the cases) detected in dogs were hyperadrenocorticism (37%), diabetes mellitus (22%), hypothyroidism (11%), and overweight/obesity (8%), whereas the main diseases (6.6% of the cases) detected in cats were diabetes mellitus (42%) and hyperthyroidism (23%). Some rare and uncommon diseases were diagnosed, such as hypoparathyroidism, pheochromocytoma, pituitary dwarfism, and diabetes insipidus, but they were present in less than 1% of the patients. Multiple endocrinopathies accounted for 8% of the cases, and the most frequent association was that between diabetes mellitus and hyperadrenocorticism in dogs and cats. The mean age of dogs was 9.11 ± 3.43 years, and 69% of the patients were female. The mean age of cats was 10.97 ± 4.29 years, and 58% of the patients were male.Discussion: The high prevalence of endocrinopathies among female dogs is closely related to the higher prevalence of diabetes mellitus and hyperadrenocorticism in female patients, and these two diseases together accounted for 59% of the cases. Among cats, the high prevalence of endocrinopathies among male cats was influenced by the large number of cases of diabetes mellitus, a disease that is typically more prevalent among tomcats. Some findings were alarming as they indicate probable lack of early diagnoses of some conditions (e.g., the prevalence of dogs with hyperadrenocorticism and diabetes three times greater than that reported by other countries), absence of patients younger than 10 years with hyperthyroidism, or failure to seek veterinary care for obese cats with initial presentation of overweight. Raising the awareness of tutors about the consequences of overweight can drastically reduce the incidence of diabetes mellitus in cats. Finally, knowledge about the characteristics of patients with the most common types of endocrinopathies is useful to clinicians as it can increase the predictive values of clinical and laboratory findings and help them include certain endocrinopathies as differential diagnoses for patients with some risk factors (age or sex). Anyway, the endocrinopathies, as well as the characteristics of the affected population in southern Brazil, are in line with similar studies on the most frequent diseases in other regions, taking into account small differences in breed and age distribution.