Effect of sampling method and storage conditions on albumin, retinol-binding protein, and N-acetyl-β-D-glucosaminidase concentrations in canine urine samples

Urinary markers for renal dysfunction are gaining interest but effects of sampling method, storage conditions, and urinary tract inflammation or infection on these markers are unclear Therefore, the objectives of the current study were to determine the difference in urinary albumin (uALB), urinary retinol-binding protein (uRBP), and urinary N-acetyl-beta D-glucosaminidase (uNAG) concentrations in cystocentesis and voided samples and to investigate concentration changes after storage at -20 degrees C and at -80 degrees C Effects of a protease inhibitor were also assessed in samples stored at -80 degrees C for 12 months In a pilot experiment, influence of in vitro hematuria, pyuria, and bacteriuria on the urinary markers was evaluated A mixed model was used to calculate mean differences and 95% confidence intervals Urinary ALB, uNAG, and uRBP concentrations were similar in voided and cystocentesis samples After storage for 4 months at -20 degrees C, uALB concentration was not affected and uRBP concentration showed a mild and clinically irrelevant decrease, whereas uNAG activity was significantly lower compared with fresh samples After storage for 12 months at -80 degrees C, uALB and uRBP concentrations did not differ from fresh samples but uNAG activity was severely decreased Protease inhibitor addition did not preserve uNAG activity Experimental hematuria, pyuria, and bacteriuria did not seem to affect urinary markers although further research is neede

Administration of progestagens to the bitch and the cat: a survey among Flemish small animal veterinary practices

Progestagens can be used to control the estrus of bitches and cats for contraceptive purposes. This implies the occurrence of both reproductive and non-reproductive side effects. However, other contraceptive methods such as surgical sterilization are alternatives of equal value. To investigate this matter, a survey about the use of progestagens in small animal practices was sent to 120 Flemish veterinarians, 80 of whom responded. The results show that surgical sterilization is recommended by 98% of the veterinarians when owners require heat control of their animal. Nevertheless, the use of progestagens remains popular, with 71% of the practices using them with dogs and 58% using them with cats. The injectable formulations of medroxyprogesterone acetate and proligestone are mostly used in bitches, while the oral administration of megestrolacetate is most commonly used in cats. Increased appetite and body weight, neoplasia of the mammary gland and cystic endometrial hyperplasia/pyometra complex were the side effects most commonly noticed by veterinarians in both species

Escherichia coli pyometra induces transient glomerular and tubular dysfunction in dogs

Background: Pyometra in dogs has been associated with renal injury. Hypothesis: Examine pyometra-related nephropathy by evaluating novel renal biomarkers. Animals: Twenty-five dogs with Escherichia coli pyometra. Fourteen clinically healthy bitches of comparable age. Methods: Prospective study. Urinary biomarkers determined by immunoassays (uIgG, uCRP, uAlb, uRBP, uTXB(2)) or colorimetric test (uNAG) with results normalized to urine creatinine concentration. Nonparametric Mann-Whitney U-test and Wilcoxon's signed-rank test used to compare healthy dogs and dogs with pyometra, and dogs with pyometra at initial and follow-up examination. Results: Urinary biomarkers (median, range) significantly increased in dogs with pyometra (uIgG/Cr: 169.7 mg/g, 4.8-1052.9; uCRP/Cr: 0.260 mg/g, 0.006-3.030; uAlb/Cr: 89.5 mg/g, 8.8-832.7; uRBP/Cr: 1.66 mg/g, 0.05-21.44; uNAG/Cr: 5.8 U/g, 1.6-27.7; uTXB(2)/Cr: 15.3 mu g/g, 3.2-139.6) compared with healthy bitches (uIgG/Cr: 3.4 mg/g, 0.6-8.9; uCRP/Cr: below detection limit; uAlb/Cr: 17.5 mg/g, 1.3-166.3; uRBP/Cr: 0.13 mg/g, 0.02-0.44; uNAG/Cr: 2.4 U/g, 1.4-7.4; uTXB(2)/Cr: 2.4 mu g/g, 1.2-4.7) (P .05). Conclusion and Clinical Importance: Pyometra-related renal dysfunction affects the nephron both at glomerular and proximal tubular level and is a transient process in most dogs with E. coli pyometra

Urinary markers in healthy young and aged dogs and dogs with chronic kidney disease

Background : Blood urea nitrogen and serum creatinine concentrations only detect a decrease of > 75% of renal functional mass. Therefore, there is a need for markers that allow early detection and localization of renal damage. Hypothesis : Urinary albumin (uALB), C-reactive protein (uCRP), retinol binding protein (uRBP), and N-acetyl-beta-d-glucosaminidase (uNAG) concentrations are increased in dogs with chronic kidney disease (CKD) compared with healthy controls and in healthy older dogs compared with young dogs. Animals : Ten dogs with CKD, 10 healthy young dogs (age 1-3 years), and 10 healthy older dogs (age > 7 years) without clinically relevant abnormalities on physical examination, hematology, biochemistry, and urinalysis. Methods : Urinary markers were determined using an ELISA (uALB, uCRP, and uRBP) or a colorimetric test (uNAG). Results were related to urinary creatinine (c). The fixed effects model or the Wilcoxon rank sum test were used to compare the different groups of dogs. Results : uALB/c, uRBP/c, and uNAG/c were significantly higher in CKD dogs than in healthy dogs. No significant difference was found for uCRP, which was not detectable in the healthy dogs and only in 3 of the CKD dogs. Between the healthy young and older dogs, no significant difference was detected for any of the markers. Conclusion : The urinary markers uALB/c, uRBP/c, and uNAG/c were significantly increased in dogs with CKD compared with healthy controls. Additional studies are needed to evaluate the ability of these markers to detect renal disease before the onset of azotemia

Urinary biomarkers for acute kidney injury in dogs

Routinely, kidney dysfunction and decreased glomerular filtration rate (GFR) are diagnosed by the evaluation of changes in the serum creatinine (SCr) and blood urea nitrogen (BUN) concentrations. However, neither of these tests is sensitive or specific enough for the early diagnosis of impaired kidney function because they are both affected by other renal and nonrenal factors. Furthermore, kidney injury can be present in the absence of kidney dysfunction. Renal reserve enables normal GFR even when nephrons are damaged. Renal biomarkers, especially those present in urine, may be useful for the study of both acute and chronic nephropathies. The aim of this review is to describe the current status of urinary biomarkers as diagnostic tools for kidney injury in dogs with particular focus on acute kidney injury (AKI). The International Renal Interest Society (IRIS) canine AKI grading system and the implementation of urinary biomarkers in this system also are discussed. The discovery of novel urinary biomarkers has emerged from hypotheses about the pathophysiology of kidney injury, but few proteomic urine screening approaches have been described in dogs. Lack of standardization of biomarker assays further complicates the comparison of novel canine urinary biomarker validation results among studies. Future research should focus on novel biomarkers of renal origin and evaluate promising biomarkers in different clinical conditions. Validation of selected urinary biomarkers in the diagnosis of canine kidney diseases must include dogs with both renal and nonrenal diseases to evaluate their sensitivity, specificity as well as their negative and positive predictive values