NEPHROCALCINOSIS IN CATS WITH CHRONIC KIDNEY DISEASE

• Grant number: 25/25911-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2026
• End date: January 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Fernanda Chicharo Chacar
• Grantee: Ana Beatriz Silveira Salvatico
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In veterinary medicine, chronic kidney disease (CKD) is a disease of great clinical relevance, which affects up to 80% of felines over 15 years of age. Nephrocalcinosis is frequently associated with CKD in this species, and is characterized by the deposition of calcium salts in the renal parenchyma. Recent studies that evaluated the association between nephrocalcinosis and CKD progression in cats presented divergent results, which highlights the importance of further investigations. Therefore, the objectives of the present study are to determine the frequency of nephrocalcinosis in cats with chronic kidney disease in all stages (IRIS), correlate clinical, laboratory, ultrasonographic findings and renal histopathological analyses, and evaluate the effect of nephrocalcinosis on the progression of CKD. To this end, 24 cats with CKD in Stages (IRIS) 1, 2, 3 and 4 will be selected, coming from routine care at the Veterinary Hospital of the Faculty of Veterinary Medicine and Animal Science of the University of São Paulo (HOVET/FMVZ/USP), according to the combination of two or more of the following criteria: (1) ionic hypercalcemia (ionic calcium > 1.4 mmol/L in at least two measurements); (2) hyperphosphatemia (serum phosphorus > 4.6 mg/dL, fasting, in at least two measurements); (3) presence of renal mineralization on ultrasound examination; (4) presence of nephrolithiasis on radiographic, ultrasonographic or post-mortem examination; (5) presence of post-mortem renal mineralization. Cats that present endocrinopathy, neoplasia, or that use furosemide, corticosteroids, supplements based on calcium or vitamin D will be excluded. Clinical parameters (general condition, appetite, muscle mass score, body condition score and systemic blood pressure) and laboratory parameters (triglycerides, cholesterol, ionic calcium, total calcium, serum phosphorus, total magnesium, urinary excretion of calcium, phosphorus and magnesium) will be evaluated; Data from cats submitted to necropsy and that meet the aforementioned criteria will also be considered. ANOVA, and Pearson or Spearman tests, to evaluate the correlation between variables, will be adopted. For all tests, a significance level of 5% will be considered (Prism, GraphPad, v. 10.0). Nephrocalcinosis is expected to occur more frequently in late stages of CKD, associated with the severity of mineral disorders and CKD progression. (AU)