Clinical Assessment of Renal Function in the Dog With a Reduction in Nephron Number*

Abstract

The viewpoint presented is that, because compensatory functional adjustment of the residual nephrons occurs in chronic renal disease, reduction in nephron number usually exceeds 70% before a diagnosis is made. The case that earlier diagnoses are likely if laboratory medicine values are measured and interpreted with a maximum of efficiency is then made. The laboratory data more commonly used in practice for the clinical assessment of renal function in the dog are presented and some comparisons with findings in man are made. The information originates from clinical and experimental observations of the authors, as well as from a literature review. The laboratory data presented and discussed includes glomerular filtration rate and the clearance of nitrogenous waste (urea and creatinine), plasma protein concentration, plasma osmolality, renal concentrating capacity, and urinary constituents, particularly its protein concentration and sediment (centrifuge deposit). All parameters recommended for the clinical assessment of chronic renal failure are considered qualitatively, and some are also dealt with quantitatively.

Creatinine in the Dog: A Review

“…Hydration state. Dehydration caused increases of P‐creatinine only when it was greater than 5% 45 . Changes in P‐creatinine were not proportional to dehydration and showed large interindividual variability 94…”

“…P‐creatinine is increased for the first few hours and remains increased for up to 12 hours after meals of raw or cooked meat 41,42 . Following ingestion of commercial food of undetermined creatine/creatinine content, increases, 43,44 decreases, 42,45 or no change 46 in P‐creatinine have been reported. Oral loading with creatine for 2–4 weeks caused a dose‐dependent increase in P‐creatinine 47,48 …”

Daily rhythm of creatinine in dog: clinical and diagnostic significance

“…However, dietary intake of creatinine may inhibit its endogenous synthesis (Walker 1960(Walker , 1961. Following ingestion of commercial food of undetermined creatine/creatinine content, increases, decreases or no changes in creatinine have all been reported (English et al 1980;Watson et al 1981;Epstein et al 1984;Evans 1987).…”

Indirect markers of glomerular filtration rate in dogs and cats: a review

“…Creatinine concentrations are increased from 1-12 hours after meals of raw or cooked meat (Watson and Church 1980;Watson et al 1981). In dogs fed with commercial food, postprandial concentrations of creatinine were reported to be increased (Evans 1987), decreased (English et al 1980;Watson et al 1981) or unchanged (Epstein et al 1984). Similar results are reported in cats: preand postprandial creatinine concentrations were comparable (Ghys et al 2015a) or lower (Reynolds et al 2015).…”