Evaluation of and the prognostic factors for cats with big kidney‐little kidney syndrome

Abstract

Background The term big kidney‐little kidney syndrome in cats has been used for many years, but the definitions are not consistent and relevant research is limited. Objective To determine the factors that differ between normal and BKLK cats, as well as to develop models for predicting the 30‐day survival of cats with ureteral obstruction (UO). Animals Sixteen healthy cats and 64 cats with BKLK. Methods Retrospective study. To define BKLK by reference to data from clinically healthy cats. The demographic and clinicopathological data among groups were statistically analyzed. Results Big kidney‐little kidney syndrome cats had higher blood urea nitrogen (BUN) (median [interquartile range] 69 [28‐162] vs 21 [19–24] mg/dL, P < .001), creatinine (5.6 [1.9‐13.3] vs 1.3 [1.05‐1.40] mg/dL, P < .001), and white blood cells (10 800 [7700‐17 500] vs 6500 [4875‐9350] /μL, P < .001) and lower hematocrit (32.8 [27.1‐38.4] vs 39.1 [38.1‐40.4]%, P < .001), urine specific gravity (1.011 [1.009‐1.016] vs 1.049 [1.044‐1.057], P < .001) and pH (5.88 [5.49‐6.44] vs 6.68 [6.00‐7.18], P = .001) compared to the control cats. A lower body temperature (BT; 38.1 [37.9‐38.2] vs 38.7 [38.3‐39.2]°C, P = .009), higher BUN (189 [150‐252] vs 91 [36‐170] mg/dL, P = .04), and creatinine (15.4 [13.3‐17.4] vs 9.0 [3.1‐14.2] mg/dL, P = .03) were found among the UO cats that were not 30‐day survivors. A combination of BUN, phosphorus, and BT can predict 30‐day survival among UO cats with an area under receiver operating characteristic curve of 0.863. (P = .01). Conclusion An increase in the length difference between kidneys can indicate UO, but cannot predict outcome for BKLK cats.

Risk factors for upper urinary tract uroliths and ureteral obstruction in cats under referral veterinary care in the United Kingdom

“…“Big kidney little kidney” syndrome was defined as a difference in longitudinal kidney measurements on imaging of >0.7 cm between the contralateral kidneys. 24 …”

“…A diagnosis of ureteral obstruction relied on statements to this effect made by board‐certified diagnostic imaging specialists in the case records and included cats considered to have partial or complete obstruction. “Big kidney little kidney” syndrome was defined as a difference in longitudinal kidney measurements on imaging of >0.7 cm between the contralateral kidneys 24 …”

“…"Big kidney little kidney" syndrome was defined as a difference in longitudinal kidney measurements on imaging of >0.7 cm between the contralateral kidneys. 24 For UUTU cases, age was recorded at the baseline visit (when first diagnosed) and for non-cases, age was recorded on the final visit date to the QMHA before or on 1 January 2019, whichever came first to allow as much time as possible to be diagnosed with UUTU before classification as a non-case. Neuter status was excluded from analyses because "entire" status was the default option within the hospital's computer software, therefore missing selection of this box during cat data entry might have led to cats being misclassified regarding neuter status.…”

The utility of clinicopathological findings and point‐of‐care ultrasound in increasing the index of suspicion of ureteral obstruction in azotaemic cats presenting to the emergency room

“…Renal asymmetry was present exclusively in OA cats in this study, however healthy patients (Wu et al . 2021) and patients with kidney disease (Bua et al . 2015, Wu et al .…”

“…2015, Wu et al . 2021) can have a degree of renal asymmetry. Bilateral nephromegaly and presence of perinephric fluid were present in both OA and NOA cats, supporting previous findings that these ultrasonographic signs are not useful in differentiating obstructed and non‐obstructed causes of azotaemia (Lamb et al .…”