AB

Case 1 - kidney malfunction

Case Overview

  • Location: University of Nottingham UK, focusing on clinical pathology in Equine studies.

Patient History

  • Patient Name: Rupert

  • Species: 17 year old Cob Gelding

  • Clinical Signs:

    • 1 week history of inappetence (loss of appetite)

    • Quiet demeanor

Physical Examination Findings

  • Mucous Membranes (MM): Pink; CRT (Capillary Refill Time): <2 seconds

  • Heart Rate (HR): 44 beats per minute

  • Respiratory Rate (RR): 12 breaths per minute

  • Temperature (T): 37.9°C

Haematology and Biochemistry Results

  • Haematology:

    • PCV%: 38 (Reference: 24-44)

    • RBC: 8.03 x 10^12/L (Reference: 5.5-9.5)

    • MCV: 47.7 fL (Reference: 40-48)

    • MCHC: 34.3 g/dL (Reference: 32-38)

    • RBC morphology: Unremarkable

    • White Blood Cells: 8.3 x 10^9/L (Reference: 6-12)

    • Seg. Neutrophils: 6.23 x 10^9/L (Reference: 2.5-7.0)

  • Biochemistry:

    • Creatinine: 1079 µmol/L (Reference: 80-140) - High

    • Urea: 34.2 mmol/L (Reference: 3.6-8.9) - High

    • ALP: 452 U/L (Reference: 40-400) - High

    • AST: 338 U/L (Reference: 150-400)

    • Total bilirubin: 43.4 µmol/L (Reference: 0-40) - High

    • Glucose: not reported

Problems Identified Based on Results

  • Protein Losing Neuropathy:

    • Indicated by low albumin levels.

  • Renal Issues:

    • High creatine and urea levels suggest kidney dysfunction.

Diagnostic Considerations

  • Working Diagnosis:

    • Need to assess the significance of the elevated urea level.

    • Consideration of pre-renal vs renal vs post-renal causes.

  • Key Insights:

    • Urea not as specific as creatinine due to hindgut fermentation in horses.

    • Elevated ALP and bilirubin indicate possible nephropathy.

    • Calcium excreted by the kidney necessitates further examination.

Further Questions for the Owner

  • Investigative Areas:

    • Medications administered (e.g., Bute, which may cause nephron damage).

    • Potential exposure to nephrotoxic plants (e.g., acorns).

    • Recent blood transfusion history (risk of Theiler's disease).

Next Diagnostic Steps

  1. Urinalysis

  2. Abdominal Ultrasound - to assess kidney pathology

  3. Biopsy - if indicated

Urinalysis Results

  • Specific Findings:

    • Specific Gravity: 1.011 (isothenuric, indicating impaired renal function). Isothenuric refers to the condition of urine that has a specific gravity similar to that of plasma, typically around 1.010. This suggests that the kidneys are not effectively concentrating or diluting the urine, which can indicate impaired renal function.

    • Protein: +++ (indicating glomerular damage)

    • Blood: ++ (suggestive of renal damage)

    • Occasional calcium carbonate crystals noted.

Trans-Abdominal Ultrasound Expectations

  • Potential Findings:

    • Enlarged or damaged kidneys suggesting pathology.

    • Hydronephrosis or presence of uroliths/neoplasia possible.

Long-term Management Considerations

  • Dietary Recommendations:

    • Advise owner on dietary management focusing on restricted diet.

    • Importance of proper mineral balance to prevent crystals.

    • Encourage small, frequent feedings with controlled fat intake.

  • Hydration Strategy:

    • Methods to increase water intake include adding molasses.

  • Medication Management:

    • Avoid nephrotoxic medications such as aminoglycosides and NSAIDs.

    • Schedule a follow-up recheck in one week to monitor changes in biochemistry and urinalysis.

Additional Diagnostic Tests

  • Referral may be warranted based on initial findings.

  • Monitor clinical response to IV fluids; lack of response in 24-48 hours could indicate chronic issues.

Possible Causes of Renal Compromise

  • Background Factors:

    • Toxin ingestion (e.g., ragwort)

    • Blood product reactions

    • NSAID toxicity

    • Dietary imbalances (excessive calcium or phosphorus).

    • UTI considerations, particularly in older geldings.

Bonus Slides

  • Fractional Excretion:

    • Importance of calculating fractional excretion to determine renal function based on serum and urine electrolyte levels.

Conclusion

  • Follow-up and Monitoring:

    • Updating working diagnosis based on additional tests and historical data.

    • Additional resources available for detailed examination.