Bone resorption in dogs with calcium oxalate urolithiasis and idiopathic hypercalciuria

Abstract

People with calcium oxalate (CaOx) urolithiasis and idiopathic hypercalciuria (IH) often have evidence of increased bone resorption, but bone turnover has not previously been investigated in dogs with these conditions. The aim of this study was to determine whether a marker of bone resorption, β-crosslaps, differs between dogs with CaOx urolithiasis and IH compared to controls. This retrospective, cross-sectional study used a canine specific ELISA to measure β-crosslaps concentrations in stored frozen serum samples from 20 dogs with CaOx urolithiasis and IH and 20 breed-, sex-, and age-matched stone-free controls (18 Miniature Schnauzers, 14 Bichons Frise, and 8 Shih Tzus). Dogs with CaOx urolithiasis and IH had lower β-crosslaps concentrations relative to controls (P = 0.0043), and β-crosslaps had a moderate negative correlation with urinary calciumto-creatinine ratios (r = −0.44, P = 0.0044). Miniature Schnauzers had lower β-crosslaps concentrations than the other two breeds (P = 0.0035). The ELISA had acceptable intra-assay precision, but concentrations decreased when samples were repeatedly assayed over time. Assay recovery rates were also below acceptance criteria. In conclusion, Miniature Schnauzers, Bichons Frise, and Shih Tzus with CaOx urolithiasis and IH have evidence of decreased bone resorption compared to stone-free controls. This suggests that other causes of IH, such as intestinal hyperabsorption of calcium, underlie risk for CaOx urolithiasis in these breeds. Results should be confirmed in larger populations and with other β-crosslaps assays and additional biomarkers of bone turnover. The stability of canine serum β-crosslaps after freeze-thaw cycles and storage at various temperatures requires investigation.

Vitamin D metabolism in dogs with and without hypercalciuric calcium oxalate urolithiasis

“…Each group included 10 Miniature Schnauzers (5 male neutered and 5 female spayed), 5 Shih Tzus (3 male neutered and 2 female spayed), and 4 Bichon Frise (3 male neutered and 1 female spayed). Thirty‐four of the dogs had participated in previously published studies on urinary metabolites and 29 had participated in a study on a serum marker of bone turnover in dogs with and without CaOx urolithiasis. Serum sample storage time before vitamin D metabolite analysis was not significantly different between groups ( P = .55) with an average of 3.5 ± 0.9 years for cases and 3.3 ± 1.4 years for controls.…”

“…The study took place at the University of Minnesota Veterinary Medical Center (UMN VMC). Stored (−80°C) serum samples were available from dogs recruited as cases and controls for genetic and metabolic studies on CaOx urolithiasis between February 2011 and November 2015 . The dogs were recruited from the patient population at the UMN VMC and through outreach to primary care veterinary clinics and breeders in Minnesota, Iowa, and Wisconsin.…”

“…Increased bone resorption is associated with urolithiasis in people . In contrast, a marker of bone resorption, serum β‐crosslaps, is decreased in dogs with hypercalciuric CaOx urolithiasis, suggesting bone turnover is not the primary mechanism underlying stone risk in dogs …”

Effects of dietary phosphates from organic and inorganic sources on parameters of phosphorus homeostasis in healthy adult dogs

“…The reference range given by the laboratory for adult dogs is 8–45 pg/ml. CrossLaps are a degradation product of mature collagen type I and therefore a biomarker for bone resorption [ 78 , 79 ]. They were analyzed with an ELISA for human serum samples, validated for dogs (Serum CrossLaps (CTX-I) ELISA kit; ids GmbH, Frankfurt/ Main, Germany).…”

Diagnosis of bacterial urinary tract infection: Utility of urine myeloperoxidase concentration to predict urine culture results in dogs

“…The inter-assay variability was 18.34%. The acceptable range of %CV is typically accepted as <15% for intraassay variability and <20% for interassay variability [14]. Based on urine spiked with standards, average percent recovery was determined to be 45% for this assay.…”