Diego Miceli Diego Miceli Stijn J M Niessen Stijn J M Niessen Juan P Rey Amunategui Juan P Rey Amunategui Florian K Zeugswetter (Clinical Centre for Small Animal Health and Research, Clinical Department for Small Animals and Horses, Departments, University of Veterinary Medicine Vienna) Florian K Zeugswetter Gustavo Pompili Gustavo Pompili Flavia Tavares Flavia Tavares Estela Molina Estela Molina Rodolfo Leal Rodolfo Leal Ignacio Espiñeira Ignacio Espiñeira Doroteia Bota Doroteia Bota Andrea Corsini Andrea Corsini Federico Fracassi Federico Fracassi Oxford University Press 2026 Background Hypersomatotropism (HST) in cats has predominantly been associated with diabetes mellitus (DM) and HST in nondiabetic cats is poorly described. Hypothesis/Objectives To describe the clinical presentation, clinicopathologic findings, and outcome of nondiabetic cats with presumed HST. Animals Twenty-eight client-owned cats. Methods Multi-site retrospective study based on medical records of nondiabetic cats seen at 10 institutions between 2014 and 2024 with presumed HST (elevated serum insulin-like growth factor-1 [IGF-1] ± clinical signs compatible with acromegaly ± documented pituitary enlargement). Clinical presentation, diagnostic findings, and survival times were reviewed. Results Twenty-eight cats with HST were included. Twenty-six cats were males, and 2 cats were females; mean age was 9.5 years (±SD 3.5 years); mean body weight was 7.1 kg (±SD 2.1 kg). The median serum IGF-1 concentration was 1236 ng/mL (range 704-2455 ng/mL). Nineteen of 28 cats (68%) had clinical signs possibly related to acromegaly: prognathia inferior (13/28), weight gain (12/28), broad facial features (10/28), abdominal enlargement (10/28), respiratory stridor (9/28), polyphagia (9/28), and signs of neurological disease (3/28). The most common clinicopathological abnormalities were hyperproteinemia (12/28), serum creatinine above the reference interval (RI) (10/28), and urinary specific gravity below the RI (9/28). Hypertrophic cardiomyopathy phenotype was identified in 8/17 cases. The most common comorbidity was chronic kidney disease (10/28). The median survival time after diagnosis was 24 months (range 1-103 months). Conclusions and clinical importance Hypersomatotropism can present without DM and should be considered in cats with signs suggestive of growth hormone excess or a pituitary tumor. PDFDocument eng 2026-08-12T08:41:17.236472514Z 2026 Acromegaly Cats GH Excess Nondiabetic 670089 b application/pdf http://creativecommons.org/licenses/by-nc/4.0/