Table 4

Renal function biomarkers, serum chemistries and urinalysis parameters for cats with IRIS stage 1 and 2 CKD fed control or test food at baseline and after consuming foods for 1, 3 and 6 months (mean±SEM)

AnalytesFood fed*BaselineMonth 1Month 3Month 6P value†
Renal function biomarkers and serum metabolites‡
 Urea nitrogen, mg/dlTest25.8±1.325.0±1.423.3±1.024.5±1.60.86
 (16.3–39.0 mg/dl)Control27.1±1.325.3±1.424.0±1.025.6±1.6
 Creatinine, mg/dlTest1.35±0.081.37±0.081.49±0111.53±0.10§0.0004
 (<1.6 mg/dl)Control1.39±0.081.61±0.081.70±0.111.64±0.10§
 SDMA, µg/dlTest12.5±0.818.1±1.220.0±1.018.5±1.20.43
 (<14 µg/dl)Control13.1±0.820.3±1.121.9±1.021.0±1.2
 Calcium, mg/dlTest9.0±0.19.2±0.29.3±0.29.7±0.2§0.0002
 (8.6–10.7 mg/dl)Control9.2±0.19.5±0.210.3±0.211.0±0.2§
 Sodium, mmol/dlTest153.0±0.4151.1±0.4152.6±0.4151.3±2.10.007
 (149–156 mmol/dl)Control151.9±0.4151.7±0.4153.3±0.4147.3±2.4
 Phosphorus, mg/dlTest4.4±0.24.5±0.24.2±0.24.5±0.20.03
 (3–6 mg/dl)Control4.2±0.24.4±0.24.8±0.24.4±0.2
 Albumin, mg/dlTest3.08±0.073.13±0.083.21±0.083.00±0.080.47
 (2.5–3.8 mg/dl)Control3.20±0.073.22±0.083.27±0.083.01±0.08
 Globulin, mg/dlTest3.54±0.123.57±0.133.74±0.133.70±0.13§0.01
 (2.5–5.3 mg/dl)Control3.41±0.123.12±0.133.51±0.133.29±0.13
 Total protein, mg/dlTest6.6±0.16.7±0.17.0±0.16.7±0.10.001
 (5.6–8.3 mg/dl)Control6.6±0.16.3±0.16.8±0.16.3±0.1§
Urinalysis parameters
 Urine-specific gravity
Test1.044±0.0031.047±0.0041.042±0.0021.043±0.0030.37
Control1.044±0.0031.044±0.0031.044±0.0021.042±0.003
 Urine creatinine, mg/dl
Test348±28402±30370±30381±300.03
Control333±28455±29451±31475±32§
 Urine protein:creatinine ratio
Test0.26±0.040.22±0.140.17±0.080.19±0.030.69
Control0.21±0.040.31±0.130.23±0.080.16±0.04
  • *Test food was Hill’s Prescription Diet k/d Feline with chicken, dry cat food (Hill’s Pet Nutrition, Topeka, Kansas, USA). Control food was Feline Renal Support A dry cat food (Royal Canin Veterinary Diet, St. Charles, Missouri, USA).

  • †P values are shown for diet×time interaction.

  • ‡Normal reference intervals are shown in parentheses.

  • §For those analytes with diet×time interaction P<0.05, indicates mean values at 6 months that were different from baseline at P≤0.05.

  • CKD, chronic kidney disease; IRIS, International Renal Interest Society; SDMA, symmetric dimethylarginine.