The use of Ribavirin to treat chronic hepatitis C in patients receiving azathioprine has been reported to induce severe pancytopenia and may increase the risk of azathioprine-related myelotoxicity. Inosine monophosphate dehydrogenase (IMDH) is required for one of the metabolic pathways of azathioprine.
There are several common underlying causes of kidney disease. 1  In older cats Interstitial Nephritis is most frequently seen. 2  Polycystic Kidney Disease (PKD) is a very common problem in Persian cats - 20-30% of them can be affected. 3  Tumours are occasionally seen in middle-aged and older cats.
Pyelonephritis in Small Animals. Kidney infection (pyelonephritis) is usually due to ascending bacteria, although hematogenous spread is possible. The organisms and predisposing causes are similar to those of bacterial cystitis. Renoliths and ureteroliths, which impede the normal flow of urine out of the renal pelvis, may be contributory.