Diagnostic Plan

Diagnostic plan

A dental cleaning was recommended, and samples were collected for a preanesthetic screen for complete blood count (CBC); chemistry panel, including the IDEXX SDMA Test; total T4; and a complete urinalysis.

Laboratory Findings

Diagnostic review

  • Noteworthy abnormalities found on Jimmy’s laboratory/diagnostic tests included an increased SDMA* of 23 μg/dL, and a low urine specific gravity of 1.015.
  • The balance of the diagnostics, including creatinine and total T4, were within the reference intervals.
  • SDMA is an earlier and more reliable biomarker for kidney function than creatinine and warrants follow-up investigation when increased.
Treatment Plan and Follow Up

Next steps

  • The owner was informed that some supportive care and follow-up were indicated for Jimmy ahead of his dental procedure.
  • Increased access to drinking water (bowl outside, and on different levels inside the home), a diet designed for senior patients,1 and a recheck appointment in 2 weeks were recommended.
  • Other considerations included diagnostic imaging of the kidneys and associated structures and assessment of blood pressure.
Action Plan and Results

Follow-up and diagnosis

  • Jimmy presented 1 month later and his lab work showed that SDMA remained increased but stable at 19 μg/dL and his urine specific gravity was unchanged at 1.015. The remainder of his laboratory results remained within the reference interval.
  • An abdominal ultrasound showed no evidence of urinary stones or infection but small kidneys, consistent with chronic kidney disease (CKD).
  • Systolic blood pressure was 175 mm Hg, which was persistently increased when Jimmy was rechecked a few days later.
  • With the results in hand, and following the International Renal Interest Society (IRIS) CKD Staging Guidelines, Jimmy was diagnosed with IRIS CKD Stage 2 disease. It was determined that Jimmy be placed on medication for his high blood pressure and that his owners switch him to a kidney therapeutic diet while continuing to provide him several fresh water sources.

Discussion

Cases like Jimmy’s are common for general practitioners, and his case reinforces that even a single elevation in SDMA warrants further investigation and possible management.

SDMA detects problems sooner, and it is more reliable than creatinine in assessing kidney function.2-6 
Making modest changes in Jimmy’s access to fresh water and instituting a kidney therapeutic diet contributed to the effort of possibly slowing the progression of Jimmy’s kidney disease. Jimmy’s kidney disease was able to be appropriately monitored and managed prior to his dental procedure. During his dental procedure, additional precautions were also taken to protect his kidneys. Longer-term regular appointments can be scheduled to monitor his kidney disease more closely thanks to the early detection afforded by SDMA. This will allow for earlier identification and treatment of kidney disease progression and complicating conditions.

Diagnostic Reports

Patient reports

Chemistry 
Jimmy01.jpg
Urinalysis 
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Hematology
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Total T4
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IRIS CKD staging guidelines
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*Symmetric dimethylarginine.

Reference

  1. Hall JA, MacLeay J, Yerramilli M, et al. Positive impact of nutritional interventions on serum symmetric dimethylarginine and creatinine concentrations in client-owned geriatric cats. PLoS One. 2016;11(4):e0153654.
  2. Nabity MB, Lees GE, Boggess M, et al. Symmetric dimethylarginine assay validation, stability, and evaluation as a marker for early detection of chronic kidney disease in dogs. J Vet Intern Med. 2015;29(4):1036–1044.
  3. Hall JA, Yerramilli M, Obare E, Yerramilli M, Jewell DE. Comparison of serum concentrations of symmetric dimethylarginine and creatinine as kidney function biomarkers in cats with chronic kidney disease. J Vet Intern Med. 2014;28(6):1676–1683.
  4. Hall JA, Yerramilli M, Obare E, Yerramilli M, Almes K, Jewell DE. Serum concentrations of symmetric dimethylarginine and creatinine in dogs with naturally occurring chronic kidney disease. J Vet Intern Med. 2016;30(3):794–802.
  5. Hall JA, Yerramilli M, Obare E, Yerramilli M, Yu S, Jewell DE. Comparison of serum concentrations of symmetric dimethylarginine and creatinine as kidney function biomarkers in healthy geriatric cats fed reduced protein foods enriched with fish oil, L-carnitine, and medium-chain triglycerides. Vet J. 2014;202(3):588–596.
  6. Hall JA, Yerramilli M, Obare E, Yerramilli M, Melendez LD, Jewell DE. Relationship between lean body mass and serum renal biomarkers in healthy dogs. J Vet Intern Med. 2015;29(3):808–814.