Vol. 9, Issue 5, Part M (2025)

Hydronephrosis, which results from urethral blockage, is a critical and potentially fatal condition in cats that requires immediate diagnosis and treatment. This study aimed to establish a relationship between the severity of hydronephrosis and changes in the important serum biochemical indicators blood urea nitrogen (BUN) and creatinine as well as describing the ultrasonographic characteristic of different grades of the condition. Seven male cats with confirmed urethral obstruction were comprehensively evaluated through a clinical examination, serum biochemistry and abdominal ultrasonography. The results indicated a statistically significant rise in both BUN and creatinine levels with the progression of hydronephrosis. Mean±SE BUN levels were 43.14±3.65 mg/dL for mild cases, increasing to 68.58±2.99 mg/dL for moderate cases and and reaching a high of 99.75±12.56 mg/dL for severe cases. Similarly, mean creatinine levels were 2.49±0.10 mg/dL, 3.78±0.31 mg/dL and 6.02±0.21 mg/dL for the respective grades. A strongly positive correlation was established between the hydronephrosis grades and biochemical markers. Ultrasonography proved to be an essential tool for precise grading of the renal pathology, revealing a clear progression of renal pelvic dilation and parenchymal thinning as the disease progressed. This study highlights the importance of a comprehensive diagnostic approach that combines biochemical analysis and imaging for the early detection, accurate grading and timely management of hydronephrosis in cats with urethral obstruction, ultimately leading to improved recovery and prognosis.