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

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

Recommended levels are well within laboratory reference ranges Hyperphosphataemia IRIS recommendations: Stage I + II: 0.81-1.45 mmol/l Stage III: 0.81-1.61 mmol/l Stage IV: 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