Editorial Type:
Analytic Techniques

Effect on urine specific gravity of the addition of glucose to urine samples of dogs and cats

Ellen N. Behrend 1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.

Search for other papers by Ellen N. Behrend in
Current site
Google Scholar
PubMed Close
 VMD, PhD
,
Annabel N. Botsford 1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.

Search for other papers by Annabel N. Botsford in
Current site
Google Scholar
PubMed Close
 DVM, MS
,
Samuel A. Mueller 1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.

Search for other papers by Samuel A. Mueller in
Current site
Google Scholar
PubMed Close
 BA
,
Erik H. Hofmeister 1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.

Search for other papers by Erik H. Hofmeister in
Current site
Google Scholar
PubMed Close
 DVM, MA, MS
, and
Hollie P. Lee 1Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849.

Search for other papers by Hollie P. Lee in
Current site
Google Scholar
PubMed Close
DOI:
https://doi.org/10.2460/ajvr.80.10.907
Volume/Issue:
Volume 80: Issue 10
Online Publication Date:
01 Oct 2019
Restricted access
Sign In Reprints and Permissions Purchase Article

Abstract

OBJECTIVE

To evaluate effects of the addition of glucose to dog and cat urine on urine specific gravity (USG) and determine whether glucosuria affects assessment of renal concentrating ability.

SAMPLE

Urine samples from 102 dogs and 59 cats.

PROCEDURES

Urine for each species was pooled to create samples with various USGs. Glucose was added to an aliquot of each USG pool (final concentration, 2,400 mg/dL), and serial dilutions of the glucose-containing aliquot were created for each pool. The USG then was measured in all samples. The difference in USG attributable to addition of glucose was calculated by subtracting the USG of the unaltered sample from the USG of the sample after the addition of glucose. The relationship between the difference in USG and the USG of the unaltered, undiluted sample was evaluated by the use of linear regression analysis.

RESULTS

Addition of glucose to urine samples increased the USG. There was a significant relationship between USG of the undiluted sample and the difference in USG when glucose was added to obtain concentrations of 300, 600, 1,200, and 2,400 mg/dL in canine urine and concentrations of 600, 1,200, and 2,400 mg/dL in feline urine. The more concentrated the urine before the addition of glucose, the less change there was in the USG. Changes in USG attributable to addition of glucose were not clinically important.

CONCLUSIONS AND CLINICAL RELEVANCE

Substantial glucosuria resulted in minimal alterations in specific gravity of canine and feline urine samples. Thus, USG can be used to assess renal concentrating ability even in samples with glucosuria.

Abstract

OBJECTIVE

To evaluate effects of the addition of glucose to dog and cat urine on urine specific gravity (USG) and determine whether glucosuria affects assessment of renal concentrating ability.

SAMPLE

Urine samples from 102 dogs and 59 cats.

PROCEDURES

Urine for each species was pooled to create samples with various USGs. Glucose was added to an aliquot of each USG pool (final concentration, 2,400 mg/dL), and serial dilutions of the glucose-containing aliquot were created for each pool. The USG then was measured in all samples. The difference in USG attributable to addition of glucose was calculated by subtracting the USG of the unaltered sample from the USG of the sample after the addition of glucose. The relationship between the difference in USG and the USG of the unaltered, undiluted sample was evaluated by the use of linear regression analysis.

RESULTS

Addition of glucose to urine samples increased the USG. There was a significant relationship between USG of the undiluted sample and the difference in USG when glucose was added to obtain concentrations of 300, 600, 1,200, and 2,400 mg/dL in canine urine and concentrations of 600, 1,200, and 2,400 mg/dL in feline urine. The more concentrated the urine before the addition of glucose, the less change there was in the USG. Changes in USG attributable to addition of glucose were not clinically important.

CONCLUSIONS AND CLINICAL RELEVANCE

Substantial glucosuria resulted in minimal alterations in specific gravity of canine and feline urine samples. Thus, USG can be used to assess renal concentrating ability even in samples with glucosuria.

Contributor Notes

Dr. Botsford's present address is Atlantic Veterinary Internal Medicine and Oncology, 10000 Old Columbia Rd, Columbia, MD 21046.

Address correspondence to Dr. Behrend (behreen@auburn.edu).
Cover American Journal of Veterinary Research
American Journal of Veterinary Research
Publication Date:
01 Oct 2019

  • 1. Stockham SL, Scott MA. Urinary system. In: Stockham SL, Scott MA, eds. Fundamentals of veterinary clinical pathology. Ames, Iowa: Blackwell Publishing, 2008;415–494.

    • Search Google Scholar
    • Export Citation

  • 2. Dossin O, Germain C, Braun JP. Comparison of the techniques of evaluation of urine dilution/concentration in the dog. J Vet Med A Physiol Pathol Clin Med 2003;50:322–325.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 3. Bauer N, Rettig S, Moritz A. Evaluation of the Clinitek status automated dipstick analysis device for semiquantitative testing of canine urine. Res Vet Sci 2008;85:467–472.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 4. Defontis M, Bauer N, Failing K, et al. Automated and visual analysis of commercial urinary dipsticks in dogs, cats and cattle. Res Vet Sci 2013;94:440–445.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 5. Chew DJ, DiBartola SP, Schenck PA. Urinalysis. In: Chew DJ, DiBartola SP, Schenck PA, eds. Canine and feline nephrology and urology. 2nd ed. St Louis: Elsevier/Saunders, 2011;1–31.

    • Search Google Scholar
    • Export Citation

  • 6. George JW. The usefulness and limitations of hand-held refractometers in veterinary laboratory medicine: an historical and technical review. Vet Clin Pathol 2001;30:201–210.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 7. Hess RS, Saunders HM, Van Winkle TJ, et al. Concurrent disorders in dogs with diabetes mellitus: 221 cases (1993–1998). J Am Vet Med Assoc 2000;217:1166–1173.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 8. Nelson RW. Canine diabetes mellitus. In: Feldman EC, Nelson RW, Reusch CE, et al, eds. Canine and feline endocrinology. 4th ed. St Louis: Elsevier, 2015;213–257.

    • Search Google Scholar
    • Export Citation

  • 9. Ayoub JA, Beaufrère H, Acierno MJ. Association between urine osmolality and specific gravity in dogs and the effect of commonly measured urine solutes on that association. Am J Vet Res 2013;74:1542–1545.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 10. Imran S, Eva G, Christopher S, et al. Is specific gravity a good estimate of urine osmolality? J Clin Lab Anal 2010;24:426–430.

  • 11. Chew DJ, DiBartola SP, Schenck PA. Clinical evaluation of the urinary tract. In: Chew DJ, DiBartola SP, Schenck PA, eds. Canine and feline nephrology and urology. 2nd ed. St Louis: Elsevier/Saunders, 2011;32–62.

    • Search Google Scholar
    • Export Citation

  • 12. Rubini ME, Wolf AV. Refractometric determination of total solids and water of serum and urine. J Biol Chem 1957;225:869–876.

  • 13. Bennett AD, McKnight GE, Dodkin SJ, et al. Comparison of digital and optical hand-held refractometers for the measurement of feline urine specific gravity. J Feline Med Surg 2011;13:152–154.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 14. Vientós-Plotts AI, Behrend EN, Welles EG, et al. Effect of blood contamination on results of dipstick evaluation and urine protein-to-urine creatinine ratio for urine samples from dogs and cats. Am J Vet Res 2018;79:525–531.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 15. Tvedten HW, Noren A. Comparison of a Schmidt and Haensch refractometer and an Atago PAL-USG cat refractometer for determination of urine specific gravity in dogs and cats. Vet Clin Pathol 2014;43:63–66.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • 16. Paris JK, Bennett AD, Dodkin SJ, et al. Comparison of a digital and an optical analogue hand-held refractometer for the measurement of canine urine specific gravity. Vet Rec 2012;170:463–465.

    • Crossref
    • Search Google Scholar
    • Export Citation

Advertisement