Chronic Kidney Disease in dogs + cats - Staging + management

Question 1

What is CKD?

Answer 1

• “structural or functional abnormalities of one or both kidneys that have been there for 3 months or longer”
  i.e. presence of kidney damage or reduced kidney function
• In CKD, compensatory/adaptive changes have already occurred, an irreversible, slowly progressive disease

Question 2

What are congenital/familial causes of CKD?

Answer 2

• Renal dysplasia
• Polycystic kidney disease - persian
• Amyloidosis - sharpei
• Fanconi syndrome

Question 3

What are acquired causes of CKD?

Answer 3

– Idiopathic tubulointerstitial nephritis
– Glomerular disease
– Amyloidosis
– Sequel to AKI
– Lower urinary tract obstruction
– Pyelonephritis
– Hypercalcaemia
– Renal neoplasia
– Nephrotoxic drugs

Question 4

What are CS of CKD?

Answer 4

• Weight loss
• Poor appetite
• Dullness, lethargy, sleeping more
• PUPD
• Dehydration
• Vomiting
• Constipation
• Poor hair coat
• Neurological signs
• Signs related to hypertension
• Oedema/ascites in severe protein losing CKD

Question 5

How do you stage CKD?

Answer 5

• Urine Protein to creatine ratio
• Blood pressure
• Plasma creatinine conc =
• Stage 1 = <140umol/l
  -some other renal abnormalities present - inadequate concentrating
• Stage 2 = 140-250umol/l
  -clinical signs usually mild (PUPD) / absent
• Stage 3 = 250-440umol/l
  -Many extra-renal clinical signs may be present
• Stage 4 = >440 umol/l
  -Requires intensive tx

Question 6

What does urea + creatinine correlate to?

Answer 6

• Urea = correlates with clinical signs
• Creatinine = correlates with GFR

Question 7

What parameters change on biochem with CKD?

Answer 7

• Albumin = decreases with protein losing nephropathy
• Potassium = low in cats with CKD
• Phosphorus = initiates 2ary hyperparathyroidism + metastatic calcification
  -linked to increased mortality + progression of CKD

Question 8

What needs to do wit creatinine before measuring for CKD?

Answer 8

• Stabilise first

Question 9

What is aims of treatment of CKD?

Answer 9

• Reduce CS
• Give good QoL to animal
• Minimise progression

Question 10

What is the first thing to do with CKD treatment?

Answer 10

• Treat uraemic crisis =
  -IVFT
  -Hartmann’s or 0.9% NaCl
  -Supply maintenance

Question 11

What animals should you not give ACE inhibitors to?

Answer 11

• Dehydrated = will dilate efferent arteriole + reduce GFR + blood pressure = dangerous on already hypotensive animal

Question 11

What should be done with stage 1 CKD?

Answer 11

• Stop all nephrotoxic drugs
• Measure BP + UPCR
• Reduce proteinuria = RAAS inhibition, Antiplatelet drugs if proteinuria severe
• Reduce BP (<160mmHg) = Telmisartan, ACEi, Amlodipine
• Combat dehydration = Wet diet

Question 12

What should be done with stage 2 CKD?

Answer 12

• All of stage 1 +
• Start renal diet =
  -protein restriction
  -Phosphate restriction
  -Fibre
  -low sodium
  -Water soluble vitamins

Question 13

If diet change not enough to reduce phosphate what should be done? What are aims?

Answer 13

• Add phosphate binder to diet
• Aims =
  -stage 2 = <1.5mmol/l
  -stage 3 = <1.6mmol/l
  -stage 4 = <1.9mmol/l

Question 14

What should be done for stage 3 CKD?

Answer 14

• Same as 1 + 2 = reduce BP, proteinuria + combat dehydration + renal diet + control phosphate <1.6mmol/l
• Treat nausea + vomiting = antiemetics (maropitant)
• Manage anaemia - EPO replacement (darbepoietin)
• Control metabolic acidosis
• Appetite stimulant = mitrazapine, capromorelin

Question 15

What should you do for stage 4 CKD?

Answer 15

• Same as stage 1,2 + 3
• Control phosphate <1.9mmol/l
• Extra fluids
• Consider euthanasia