Chronic Renal Failure in
Cats: Can we Halt the Decline?
Martha Cannon
BA VetMB DSAM(Fel)
RCVS Specialist in Feline Medicine
Oxford Cat Clinic
01865 243000
Chronic Kidney Disease
Progression of renal failure
100%
Early renal
failure &
clinical signs
(azotaemia)
Death
33%
25%
10%
Early renal disease
(loss of renal reserve)
Renal
insufficiency
Uraemia
Chronic Kidney Disease
Consequences of Kidney Disease
Polyuria / polydipsia  dehydration
Nausea  vomiting / inappetence
Renal secondary hyperparathyroidism ( Phos)
Proteinuria
Hypertension
Hypokalaemia
Urinary tract infections
Anaemia
IRIS Staging System
Creatinine
Serum Phosphate
Proteinuria
Blood Pressure
CRF: IRIS Staging System
Creatinine: After treating dehydration
Stage 1: Non-azotaemic
> 33% nephrons
Stage 2: Creat 140 – 250
33-25% nephrons
Stage 3: Creat 251 – 439
25-10% nephrons
Stage 4: Creat > 440
<10% nephrons
Aims of Treatment
Stage 2: Creatinine 140-250 μmol/l
Aim: (Reverse the cause) Prevent progression
(Serum phosphate, urine protein and UTI’s, blood pressure)
Stage 3: Creatinine 251-439 μmol/l
Aim: Prevent progression and manage azotaemia to
improve quality of life
Stage 4: Creatinine >440 μmol/l
Treatment mostly aimed at managing azotaemia
IRIS Staging System
Creatinine
Serum Phosphate
Proteinuria
Blood Pressure
Hyperphosphataemia
IRIS recommendations:
Stage I + II:
Stage III:
Stage IV:
0.81-1.45 mmol/l
0.81-1.61 mmol/l
0.81-1.94 mmol/l
Recommended levels are well within
laboratory reference ranges
Hyperphosphataemia
Reduced phosphate diet is most
effective treatment
Additional advantages of prescription
diets
Reduced azotaemia, K+ supplement, Vit B
supplement, soluble fibre, ? Omega-3 FAs
Hyperphosphataemia
Protein Restricted Diet
Reduces uraemia
Improves well-being, appetite, activity
Reduces dietary phosphate intake
Controls hyperphosphataemia
Prolongs life-span
Median 800 days vs 264 days
Hyperphosphataemia
Reduced phosphate diet is most
effective way to control phosphate
Additional advantages of
prescription diets
Reduced azotaemia, K+
supplement,
Vit B supplement, Soluble
fibre,
Omega-3 FAs ... ...
Chronic Kidney Disease
Nutritional Management
Ensure adequate intake
Delay introduction until cat feels well
Learned food aversion
Canned diets
Energy from fat cf carbohydrate
Increased fluid intake
Phosphate Binders
Hyperphosphataemia
despite dietary control
Allow 6-8 weeks for
control of phosphate
Gradual introduction of
binder if phosphate
remains high
Hyperphosphataemia
Intestinal Phosphate Binders
~10% reduction in serum phosphate
Give mixed with food
Divide between all meals
Introduce gradually and titrate to effect
Monitor serum calcium when introducing binders
IRIS Staging System
Creatinine
Serum Phosphate
Proteinuria
Blood Pressure
IRIS Staging System
Rule out UTI / FLUTD
Must check urine sediment or culture
Asymptomatic bacterial urinary infections
are common in cats with CKD,
especially female cats
IRIS Staging System
Proteinuria with no active sediment
UP:C > 0.4 = proteinuric
Treat with an ACE inhibitor
UP:C < 0.2 = non-proteinuric
No treatment required
UP:C 0.2-0.4 =borderline
Monitor / treat
Chronic Renal Failure
Urinary Tract Infections
Asymptomatic UTI’s
Female cats
Low urine SG
? Occult pyelonephritis
Risk of ascending infection  renal damage
Chronic Renal Failure
Urinary Tract Infections
Treatment
4-6 weeks of antibiotic
Bactericidal antibiotic
Repeat urine sediment +/- culture
Before end of antibiotics
10 days after ceasing antibiotics
IRIS Staging System
Creatinine
Serum Phosphate
Proteinuria
Blood Pressure
CRF: IRIS Staging System
Hypertension
Common
consequence of CRF
Contributes to
progression of CRF
CRF: IRIS Staging System
Blood Pressure
“Risk of end organ damage”
< 150 mmHg = Minimal risk
150-160 mmHg = Low risk
160-180 mmHg = Moderate risk
> 180 mmHg = High risk
www.iris-renal.com
CRF: Blood Pressure
For cats with CRF
Maintain BP below 170 mmHg
Amlodipine: 0.625 – 1.25 mg per cat per day
1/8 or 1/4 of a tablet once daily
Adjunctive Treatment
Benazepril
Chronic Renal Failure in
Cats: Can we Halt the Decline?
Martha Cannon
BA VetMB DSAM(Fel)
RCVS Specialist in Feline Medicine
Oxford Cat Clinic
01865 243000