Changes in Renal Peritubular Capillaries in Canine and Feline Chronic Kidney Disease.

Renal capillary rarefaction is a crucial event that leads to tubulointerstitial damage during the progression of chronic kidney disease (CKD). In the present study, changes in CD34-positive renal capillaries were investigated in dogs and cats with CKD. A significant decrease in CD34-positive capillaries was observed in canine diseased kidneys, even at the early stage of disease. In cats, CD34-positive capillaries were well preserved in the diseased kidneys, with no link to the severity of CKD. Renal capillary rarefaction might be a trigger event that leads to the progression of CKD in dogs, rather than in cats.