Chronic renal failure

Question 1

What is chronic kidney disease?
what is the differnece betwween failure and disease?

Answer 1

• Chronic, irreversible progressive disease of the kidneys
• > 3 months duration
• Functional or structural
  
  • Chronic reduction in GFR
• Failure means end stage
  
  • Not always the case
• Chronic Kidney Disease is preferred terminology
  
  • In line with humans and small animal

Question 2

What is the pathogenesis of chronic kideney disease?

Answer 2

• A normal kindey the has an AKI that undergoes maladaptive repair and therefore sufferes from progressive scarring
• a Chronicly diseased kidney that suffers an KI that undergoes maladaptive repair and therefore sufferes from progressive scarring

Question 3

What are the two broad causes of chronic kidney disease?
Give examples

Answer 3

• Primary Glomerular Disease - Glomerular nephritis
  
  • Immune complex deposition (can get subclinical with no CRD) - Streptococcus spp, Equine infectious anaemia virus
• Primary Tubulointerstitial Disease - Most common cause in older horses
  
  • AKI/ARF causes (haemodynamic + nephrotoxins)
  • (chronic interstitial nephritis)

Question 4

What are the clinical signs of chronic renal disease inthe horse?

Answer 4

Non-specific
* Weight loss
* PU/PD
* Ventral oedema

Less common
* Poor appetite
* Dull hair coat
* Dental tartar

Question 5

what is the clinicla pathology seen with chronic renal disease inthe horse?
( haem, urinalysis, dipstick, Electrolytes)

Answer 5

History + Clinical Signs + laboratory findings
* Increased Creatinine (SDMA up and coming) - small increases in creatinin are of little value in CKD but very important in AKI
* Urinalysis
* USG often 1.009-1.014
* Cytology
* Casts
* Tubular cells
* Neoplastic cells
* Leukocytes
* Dipstick
* Proteinuria
* (urine protein:urine creatinie)
* Serum Electrolytes
* Hypercalcaemia
* Non specific
* Hyponatraemia
* Hypochloraemia
* Hyperkalaemia
* Hypoalbuminaemia
* Anaemia

Question 6

Is transabdominal ultrasound useful for chronic kidney disease?

Answer 6

• Useful for structural - Rule out nephroliths
• Often normal!
• May see - Smaller kidneys? (Normal 15-18cm in length TBs)

Question 7

How is renal biopsy done in a referal setting?

Answer 7

• Standing sedation
• Sterile (Prep + local anaesthesia)
• Right kidney (Left can be done…)
• Ultrasound guided
• Automated biopsy gun
• Complication rate 10-15%
• Check blood pressure
  
  • Humans
    
    • Hypertension due to CKD increases bleeding complications during biopsy

Question 8

What is the management (not dietary) of chronic kidney disease?

Answer 8

• What does the biopsy say?
  
  • Glomerulonephritis (including immune mediated)
    
    • Steroids if immune mediated
• Ensure infection is under control (consider antibiotics as well)
• Avoid toxic insults (refer to ARF nephrotoxic type)
• Plenty of fresh water
  
  • Encourage diuresis

Question 9

What is the dietary management of chronic kidney disease?

Answer 9

• Balanced protein
• Low salt
• Low carbohydrates
• Add vegetable oil
  Start slow, max 100mL/day (can split in multiple feeds)
• Encourage diuresis
  
  • Plain water +
  • Molasses water
  • Electrolyte water
  • Salt licks