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.