Endocrine diseases in Brazilian hospital and referral small-animal caseloads: systematic review and meta-analysis of proportions

Endocrinopathies are common chronic disorders in small-animal practice, and accurate estimation depends on standardised diagnostic criteria and denominator-defined populations. Brazilian epidemiological evidence is mostly drawn from hospital and referral settings, resulting in fragmented coverage, poor generalisability, and marked between-study heterogeneity. Conversely, VetCompass in the United Kingdom integrates standardised primary-care electronic records and supports denominator-based population inference. Searches were last updated in January 2026 and covered PubMed, Web of Science, Scopus, VETINDEX, LILACS (via BVS-Vet), SciELO, and grey literature (2005–2025). A total of 2,501 records were identified, of which 13 studies met the eligibility criteria. Two reviewers independently screened studies, extracted data, and appraised methodological quality using the JBI checklist. Random-effects meta-analyses of proportions (frequency estimates) were undertaken where appropriate, with heterogeneity quantified using I². When quantitative synthesis was not appropriate, results were synthesised narratively. In Brazilian dogs, reported frequencies varied widely across studies and were strongly setting-dependent, consistent with referral and selection effects. Across outcomes, estimates ranged from very low frequencies in broad hospital caseloads to substantially higher proportions in specialised endocrinology referral cohorts (e.g., diabetes mellitus, hypothyroidism, and hypercortisolism). Hyperparathyroidism was consistently rare (0.01%–0.07%). Hypoadrenocorticism was uncommon (0.09% in a multicentre cohort). In cats, hyperthyroidism frequencies also varied substantially by setting. Evidence on diabetes mellitus was limited to a single endocrinology referral cohort, reflecting a selected population. Brazilian results are therefore reported as study-specific frequencies. In the present study, VetCompass estimates are used as a primary-care benchmark to contextualise Brazilian hospital-based frequencies and illustrate setting effects (primary versus tertiary care). They are not used to infer true between-country differences in population prevalence. As a primary-care benchmark, UK studies report canine hypercortisolism at 0.28% (95% CI: 0.25–0.31), hypothyroidism at 0.23%, and diabetes mellitus at ~0.34%. For feline hyperthyroidism, prevalence is 2.4% overall and 8.7% among cats aged ≥10 years. Overall, the Brazilian evidence base largely reflects tertiary-care caseloads, and most studies were at high risk of bias. This reinforces the need for multicentre primary-care surveillance in Brazil supported by harmonised diagnostic criteria and interoperable electronic records.