Hydronephrosis - Atlas of swine pathology
Where: genitourinary system, kidney
Possible causes: Other
This pathological lesion, was found in a fattening pig at the slaughterhouse, is due to occlusion (by a nearby inflammatory or neoplastic growth) or obstruction (Bladder stones) of the urinary tract, with consequent difficulty or interruption of urine flow. Poor implantation of ureters in the bladder has also been described as a cause of hydronephrosis in pigs. Initially there is urine buildup in the area before the point of occlusion or obstruction of the ureter. It distends, increasing its diameter and thinning its wall. As urine builds up in a distal direction, the renal pelvis ends up being affected by the bloating process caused by urinary stasis. Later, the retained urine compresses the renal parenchyma which is sometimes reduced to a millimeter thick below the capsule.