Previously presented in part at the 16th Annual Congress of the European College of Veterinary Internal Medicine Companion Animals (ECVIM-CA), Amsterdam, The Netherlands, September 14–16, 2006.
Glomerular Filtration Rate Estimated by 3-Sample Plasma Clearance of Iohexol in 118 Healthy Dogs
Article first published online: 14 FEB 2008
Copyright © 2008 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 22, Issue 1, pages 66–73, January–February 2008
How to Cite
Bexfield, N.H., Heiene, R., Gerritsen, R.J., Risøen, U., Eliassen, K.A., Herrtage, M.E. and Michell, A.R. (2008), Glomerular Filtration Rate Estimated by 3-Sample Plasma Clearance of Iohexol in 118 Healthy Dogs. Journal of Veterinary Internal Medicine, 22: 66–73. doi: 10.1111/j.1939-1676.2007.0035.x
- Issue published online: 14 FEB 2008
- Article first published online: 14 FEB 2008
- Submitted April 22, 2007; Revised June 14, 2007; Accepted September 28, 2007.
- Renal function;
- Simplified method
Background: Glomerular filtration rate (GFR) decreases in the aging human kidney, but limited data exist in dogs.
Hypothesis: There is an effect of age and body size on estimated GFR in healthy dogs.
Animals: One hundred and eighteen healthy dogs of various breeds, ages, and body weights presenting to 3 referral centers.
Methods: GFR was estimated in clinically healthy dogs between 1 and 14 years of age. GFR was estimated from the plasma clearance of iohexol, by a compartmental model and an empirical correction formula, normalized to body weight in kilograms or liters of extracellular fluid volume (ECFV). For data analysis, dogs were divided into body weight quartiles 1.8–12.4, 13.2–25.5, 25.7–31.6, and 32.0–70.3 kg.
Results: In the complete data set, there was no trend toward lower estimated GFR/kg or GFR/ECFV with increasing age. GFR decreased with age in dogs in the smallest weight quartile only. A significant negative linear relationship was detected between body weight and estimated GFR/kg and GFR/ECFV. Reference ranges in different weight quartiles were 1.54–4.25, 1.29–3.50, 0.95–3.36, and 1.12–3.39 mL/min/kg, respectively. Standardization to ECFV rather than kilogram body weight did not produce substantial changes in the relationships between GFR estimates and age or weight.
Conclusions and Clinical Importance: Interpretation of GFR results for early diagnosis of renal failure should take into account the weight and the age of the patient for small dogs.