This study was carried out at the Clínica Veterinaria Germanías, Gandía-Valencia, Spain and the Veterinary Teaching Hospital of the University of Murcia, Murcia, Spain. Preliminary results of this work were presented in poster format at the 26th ACVIM Forum, San Antonio, 2008.
Calcium and Phosphorus Homeostasis in Dogs with Spontaneous Chronic Kidney Disease at Different Stages of Severity
Article first published online: 17 NOV 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 1, pages 73–79, January/February 2010
How to Cite
Cortadellas, O., Fernández del Palacio, M.J., Talavera, J. and Bayón, A. (2010), Calcium and Phosphorus Homeostasis in Dogs with Spontaneous Chronic Kidney Disease at Different Stages of Severity. Journal of Veterinary Internal Medicine, 24: 73–79. doi: 10.1111/j.1939-1676.2009.0415.x
- Issue published online: 4 JAN 2010
- Article first published online: 17 NOV 2009
- Submitted April 1, 2009; Revised September 10, 2009; Accepted September 23, 2009.
Background: Studies in dogs with experimental chronic kidney disease (CKD) have demonstrated that abnormalities of calcium-phosphorus (Ca-P) homeostasis occur frequently and have a negative effect on kidney function and survival. However, the prevalence of these alterations in dogs with naturally occurring CKD at different stages of severity has not yet been investigated.
Hypothesis: Abnormalities of Ca-P metabolism occur early in the course of CKD with an increased prevalence in more severe stages.
Animals: Fifty-four dogs with CKD and 22 healthy dogs.
Methods: Blood and urine samples were obtained for a CBC, biochemistry, determination of parathyroid hormone (PTH), calcitriol, and ionized calcium concentrations and urinalysis. Based on urine protein/creatinine ratio and serum creatinine concentration, dogs were grouped according to the IRIS classification for CKD.
Results: Hyperparathyroidism (HPTH) (PTH ≥ 48 pg/mL) was diagnosed in 41 (75.9%) dogs with CKD. Its prevalence increased from 36.4% (stage 1) to 100% (stage 4). Hyperphosphatemia (P > 5.5 mg/dL) was present in 37 (68.5%) dogs; increasing in prevalence from 18% (stage 1) to 100% (stage 4). Receiver-operating characteristic curve analysis showed that serum phosphorus concentration in the 4.5–5.5 mg/dL range correctly identified the presence of HPTH in most dogs. Calcitriol concentration progressively decreased in dogs with CKD and differences became statistically significant by stage 3.
Conclusion and Clinical Relevance: HPTH and hyperphosphatemia occur frequently in dogs with naturally occurring CKD, even at early stages of CKD in some dogs. These findings highlight the importance of monitoring these parameters early in the course of CKD.