Acute on chronic kidney disease in cats: Etiology, clinical and clinicopathologic findings, prognostic markers, and outcome

Abstract

Background Chronic kidney disease (CKD) and acute decompensation of CKD (ACKD) are common in cats. Objectives To characterize the etiology, clinical and clinicopathologic findings, and the short‐ and long‐term prognosis of feline ACKD. Animals One hundred cats with ACKD. Methods Retrospective study, search of medical records for cats with ACKD. Results Common clinical signs included anorexia (85%), lethargy (60%), weight loss (39%), and vomiting (27%). Suspected etiologies included ureteral obstruction (11%), renal ischemia (9%), pyelonephritis (8%), others (6%), or unknown (66%). Hospitalization duration was longer in survivors versus nonsurvivors (median = 7 days, range = 2‐26 versus median = 3 days, range = 2‐20, respectively, P < .001). The survival rate to discharge was 58%. Age, serum creatinine, urea, and phosphorous concentrations were higher and venous blood pH was lower in nonsurvivors. However, only serum phosphorus remained associated with the short‐term outcome in the multivariable model ( P = .02; 95% confidence interval = 1.03‐1.39). Survivors had a median survival time of 66 days after discharge. Serum creatinine concentrations at presentation as well as at discharge were associated with long‐term survival ( P < .002 for both). Conclusions The short‐term prognosis of ACKD is comparable to acute kidney injury, while the long‐term prognosis is guarded.

Acute on chronic kidney disease in dogs: Etiology, clinical and clinicopathologic findings, prognostic markers, and survival

“…In our study, inflammatory conditions, followed by pyelonephritis and ischemia, were the common presumptive causes, consistent with the causes of ACKD in cats. 16 This observation is in contrast with previous results of dogs with AKI, in which ischemia was the most common cause, followed by nephrotoxicity, a major cause of AKI in dogs, 9,10,13 which was not documented in our study. It is possible that dogs previously diagnosed with CKD may be less exposed to nephrotoxic substances because of enhanced owner awareness.…”

“…Median hospitalization duration was 5 days and is comparable to hospitalization duration of dogs with AKI and cats with ACKD. 9,16 Hospitalization duration in nonsurvivors was shorter, as expected, because of early death or euthanasia. Hospitalization duration was significantly longer for dogs surviving to discharge, consistent with a previous study indicating that dogs with AKI surviving 5 hospitalization days are more likely to recover.…”

“…28 Lack of an identifiable cause of ACKD in our study was not associated with a worse short-or long-term outcome, and should not be considered a negative prognostic factor, in agreement with a recent study of ACKD in cats. 16 In the univariable analysis, concentrations of creatinine, urea and phosphorus, RBC count and CK activity at presentation were associated with outcome. Azotemia and hyperphosphatemia are expected to be associated with the prognosis because they reflect the severity of kidney dysfunction.…”

“…5 In both ACKD and AKI, the common clinical signs are nonspecific, and include lethargy, anorexia and vomiting. 13,16 This clinical similarity at presentation, with presence of concurrent azotemia in both conditions, can make the differentiation between the 2 conditions challenging. Differentiation is especially difficult when clear history and clinical signs of CKD are absent, recent SCR is not available, and ultrasonographic evidence of CKD is equivocal or absent.…”

“…It appears that dogs with ACKD have poorer long-term prognosis compared to those with AKI and absence of CKD, consistent with findings in cats with ACKD. 16 The long-term prognosis of dogs with CKD largely depends on disease stage. In a retrospective study of 107, 214 dogs with CKD, the overall MST was 226 days, with significant differences among IRIS CKD stages.…”