Exploratory Study of the Urine Protein-to-Creatinine Ratio in Apparently Healthy Horses.
Abstract: Currently, there is relatively little published information on the urine protein-to-creatinine (UPC) ratio in horses, a parameter commonly used in dogs and cats. The aim of this study was to determine the reference range of UPC in urine samples of apparently healthy horses and to assess the influence of age and sex. Urinalysis and the determination of urinary protein and creatinine concentrations and ratios were performed. A total of 118 urine samples from apparently healthy horses were included in the study: 10 from foals younger than 6 months and 108 from horses older than 1 year. The median UPC for foals younger than 6 months and horses aged 1-4 years, 5-10 years, 11-17 years and older than 18 years were 0.074, 0.073, 0.070, 0.083, and 0.070, respectively. Using the non-parametric Kruskal-Wallis test, statistically significant differences were found between the youngest age group and both groups of adult horses (i.e., 5-10 years and 11-17 years); however, these differences were not confirmed by the General Linear Model, likely due to the small sample sizes in some categories. There was no effect of sex on UPC. The indicative reference range was set for the group of horses aged 5-17 years as 0.02-0.18.
Publication Date: 2025-08-21 PubMed ID: 40872733PubMed Central: PMC12389935DOI: 10.3390/vetsci12080783Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
Overview
- This study investigated the urine protein-to-creatinine (UPC) ratio in healthy horses to establish reference values and examine how age and sex might influence this ratio.
Background
- The UPC ratio is a common diagnostic metric in veterinary medicine for assessing kidney function and proteinuria in dogs and cats.
- There is limited data on UPC ratios specifically for horses, which makes understanding normal ranges and influencing factors important for equine health assessments.
Objectives
- To determine reference ranges of the UPC ratio in apparently healthy horses.
- To evaluate whether age and sex have an effect on the UPC ratio in horses.
Methods
- Sample Collection: 118 urine samples were collected from apparently healthy horses.
- Age Groups: Samples came from foals younger than 6 months (10 samples) and horses older than 1 year (108 samples), divided into further age brackets: 1-4 years, 5-10 years, 11-17 years, and older than 18 years.
- Measurements: Each urine sample underwent urinalysis, including the determination of protein and creatinine concentrations to compute the UPC ratio.
- Statistics: The researchers used the non-parametric Kruskal-Wallis test to compare groups and a General Linear Model to verify statistical significance while accounting for sample size effects.
Results
- Median UPC Ratios by Age Group:
- Foals < 6 months: 0.074
- 1-4 years: 0.073
- 5-10 years: 0.070
- 11-17 years: 0.083
- >18 years: 0.070
- Statistical Findings:
- The Kruskal-Wallis test suggested significant differences between the youngest foals (<6 months) and adult groups aged 5-10 and 11-17 years.
- The General Linear Model did not confirm these differences, likely due to the small number of samples in some age groups.
- Effect of Sex:
- No significant influence of sex on UPC values was found.
- Reference Range:
- For horses aged 5-17 years, an indicative UPC reference range was established between 0.02 and 0.18.
- This range may help veterinarians distinguish normal from pathological protein excretion in equine urine.
Conclusions and Implications
- The study provides preliminary reference data for the UPC ratio in healthy horses, which can be used for clinical interpretation of equine urinalysis.
- Age may influence UPC ratios, although more data are needed to confirm the significance of these observations given small sample sizes, especially in foals and older horses.
- Sex does not appear to affect the UPC ratio in horses, simplifying the application of reference ranges without sex stratification.
- These findings support the potential utility of UPC ratio measurements in equine medicine, similar to their established use in small animal practice.
Cite This Article
APA
Kovarikova S, Blahova J, Steffenova V, Vaskova N, Jahn P.
(2025).
Exploratory Study of the Urine Protein-to-Creatinine Ratio in Apparently Healthy Horses.
Vet Sci, 12(8), 783.
https://doi.org/10.3390/vetsci12080783 Publication
Researcher Affiliations
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences, 61242 Brno, Czech Republic.
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences, 61242 Brno, Czech Republic.
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences, 61242 Brno, Czech Republic.
- Department of Animal Protection and Welfare and Veterinary Public Health, Faculty of Veterinary Hygiene and Ecology, University of Veterinary Sciences, 61242 Brno, Czech Republic.
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary Sciences, 61242 Brno, Czech Republic.
Grant Funding
- 2024ITA26 VETUNI / University of Veterinary Sciences, Brno, Czech Republic
Conflict of Interest Statement
The authors declare no conflicts of interest.
References
This article includes 22 references
- Piech TL, Wycislo KL. Importance of Urinalysis. Vet. Clin. N. Am. Small Anim. Pract. 2019;49:233–245.
- Galen GV, Olsen E, Siwinska N. Biomarkers of Kidney Disease in Horses: A Review of the Current Literature. Animals 2022;12:2678.
- Segev G, Cortellini S, Foster JD, Francey T, Langston C, Londoño L, Schweighauser A, Jepson RE. International Renal Interest Society best practice consensus guidelines for the diagnosis and management of acute kidney injury in cats and dogs. Vet. J. 2024;305:106068.
- Harley L, Langston C. Proteinuria in dogs and cats. Can. Vet. J. 2012;53:631–638.
- Herman N, Bourgès-Abella N, Braun JP, Ancel C, Schelcher F, Trumel C. Urinalysis and determination of the urine protein-to-creatinine ratio reference interval in healthy cows. J. Vet. Intern. Med. 2019;33:999–1008.
- Frączkowska K, Trzebuniak Z, Żak A, Siwińska N. Measurement of Selected Renal Biochemical Parameters in Healthy Adult Donkeys Considering the Influence of Gender, Age and Blood Freezing. Animals 2021;11:1748.
- Athanasiou LV, Katsoulos PD, Spanou VM, Pazarakioti AT, Katsogiannou EG, Iliadi I, Baka R, Polizopoulou ZS. Effect of storage time on the urine protein: Creatinine ratio in alkaline ovine urine. J. Vet. Diagn. Investig. 2021;33:1176–1179.
- Kovarikova S, Blahova J, Truhlarova A, Baslerova S, Krepinska I, Jekl V. Urinary protein-to-creatinine ratio in guinea pigs (Cavia porcellus): Reference range and the effect of age and sex. Vet. Rec. 2024;196:e4911.
- Sze-Yu Y, Chi-Hsuan S, Pin-Chen L, Ching-Fen W, Tsai-Lu L, Tsung-Li C, Chou CC. Urinary chemistry in healthy cross-bred pet rabbits (Oryctolagus cuniculus) and rabbits with suspected chronic kidney disease. Transl. Anim. Sci. 2025;29:txaf002.
- Lammey ML, Ely JJ, Zavaskis T, Videan E, Sleeper MM. Effects of aging and blood contamination on the urinary protein-creatinine ratio in captive chimpanzees (Pan troglodytes). J. Am. Assoc. Lab. Anim. Sci. 2011;50:374–377.
- Cannizzo SA, Langan JN, Warneke M, Allender M. Evaluation of in-house urine dipstick, reference laboratory urinalysis, and urine protein: Creatinine ratio from a colony of callimicos (Callimico goeldii). J. Zoo Wildl. Med. 2016;47:977–983.
- Fasoli S, Andreani G, Dondi F, Ferlizza E, Bellei E, Isani G. Urinary Reference Values and First Insight into the Urinary Proteome of Captive Giraffes. Animals 2020;10:1696.
- Rauch-Schmücking H, Bohner J, Goeritz F, Bakker D, Stalder G, Stenvinkel P, Johnson RJ, Shiels PG, Redtenbacher I, Azogu-Sepe I. Cystocentesis and urinalysis in zoomedicine: An underestimated tool for large felid standard health checks. J. Zoo Wildl. Med. 2024;55:555–564.
- Uberti B, Eberle DB, Pressler BM, Moore GE, Sojka JE. Determination of and correlation between urine protein excretion and urine protein-to-creatinine ratio values during a 24-hour period in healthy horses and ponies. Am. J. Vet. Res. 2009;70:1551–1556.
- Brewer BD, Clement SF, Lotz WS, Gronwall R. Renal clearance, urinary excretion of endogenous substances, and urinary diagnostic indices in healthy neonatal foals. J. Vet. Intern. Med. 1991;5:28–33.
- Arosalo BM, Raekallio M, Rajamäki M, Holopainen E, Kastevaara T, Salonen H, Sankari S. Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins.. Acta Vet. Scand. 2007;49:4.
- Uberti B, Pressler BM, Alkabes SB, Chang CY, Moore GE, Lescun TB, Sojka JE. Effect of heparin administration on urine protein excretion during the developmental stage of experimentally induced laminitis in horses.. Am. J. Vet. Res. 2010;71:1462–1467.
- Edwards DJ, Brownlow MA, Hutchins DR. Indices of renal function: Reference values in normal horses.. Aust. Vet. J. 1989;66:60–63.
- Hekmatynia F, Eskandarzadeh N, Imani M, Rezaei M, Zamani-Ahmadmahmudi M. The diagnostic performance of human urinary dipsticks to estimate urine pH, specific gravity (SpG), and protein in horses: Are they reliable?. BMC Vet. Res. 2019;15:242.
- Edwards DJ, Brownlow MA, Hutchins DR. Indices of renal function: Values in eight normal foals from birth to 56 days.. Aust. Vet. J. 1990;67:251–254.
- Scarpa P, Di Fabio V, Ramirez C, Baggiani L, Ferro E. Proteinuria, GGT index and fractional clearance of electrolytes in exercising athletic horses.. Vet. Res. Commun. 2007;31:339–342.
- Kovarikova S, Blahova J, Vanova I, Marsalek P. Comparison of two methods of measuring the urinary protein concentration for the determination of the urinary protein to creatinine ratio in various animal species.. Vet. Med. 2024;69:273–280.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
