Monitoring Renal Disease

Gary Coxon BVetMed MRCVS

Veterinary Advisor Vetoquinol UK and Ireland

Agenda

• Consequences of renal failure• Aims of management• Medications and monitoring

IRIS (International Renal Interest Society)

• Website at www.iris-kidney.com• Group of specialists that have created guidelines for

• Staging kidney disease• Treatment at various stages of kidney disease in cats and

dogs• Good education section on proteinuria, urine collection, USG

etc

Renal Failure

• Multiple underlying causes with same outcome

• Progressive and dynamic condition• Clinical signs vary and only appear when 66-

75% of functional tissue has been lost• Replaced by fibrous or scar tissue• GFR no longer adequate

Diagnosis

• Clinical signs• Changes in urine specific gravity• Changes in blood levels (Urea / Creatinine)

Urine changes (specific gravity)

Blood changes (urea/creat)

¾ Loss

2/3 Loss

Clinical sign Proportion of cats affected Dehydration 67%Anorexia 64%Lethargy/depression 52%Weight loss 47%PU/PD 32%Vomiting 30%Macrorenale 25%Microrenale 19%Pale mucosae 7%Oral ulceration 5%Diarrhoea 4%Retinal detachment 4%Less common clinical signs Haematuria/dysuria, Poor

coat, Halitosis, Osteodystrophy,

Constipation

Management

• Directed at complications of decreased kidney function

• “Conservative medical management”• Needs to be monitored

Goals of Management

• Correct imbalances and deficits in fluids and electrolytes

• Limit progressive loss of functional tissue• Manage clinical signs• Ensure adequate but correct nutrition

Major Factors That Lead to Progression

1. Hyperphosphataemia and its consequences

• Controlling phosphate proven to increase life expectancy

• The earlier treatment is started the better the prognosis

• Prevent mineralisation and therefore prevent chronic inflammation

Renal secondary hyperparathyroidism

Phosphate Management

• Restrict dietary phosphorus• Decrease intake• Decrease absorption eg. Ipakitine

• Maintain phosphate in levels set out by experts• Gives extension to lifespan

Serum Phosphate

• Establish “stage” of renal failure• IRIS guidelines ( www.iris-kidney.com )

• Look up target phosphate level• Adjust phosphate binder and/or food

Target Phosphate Levels

“Normal” serum

phosphate ranges

recommended by

commercial

laboratories

and in-house

analyzers for cats

Survival of cats Median survival times of catswith serum phosphate outside orinside new stipulated phosphate

reference ranges2

Calcium carbonateCompound with proven phosphate binding properties

ChitosanDerived fromchitin, the main buildingmaterial ofthe exoskeleton of arthropods

Speci c molecular properties

Adsorbant in the intestines

PhosphatesSomeuraemic toxins

Ipakitine®

The original UK phosphate binderformulated speci cally for veterinary use

For cats and dogs

Tasteless powder for addition to food

Contents

Formulations

• 50g• 150g• 1g/5kg BID• MUST be added to food

2. Systemic Hypertension• May be a cause or consequence of renal disease• Occurs in up to 66% of cats with CRF• Causes end organ damage – renal, ocular, CNS• In the kidney persistent glomerular hypertension lead to

hypertensive damage and nephron death• Reduction in GFR Activation of RAAS Angiotensin II CO and peripheral vascular resistance BP

Treatment of Hypertension• Calcium channel blocker

• Amlodipine (Istin) 5mg tablets• Typical dose 0.625-1.25mg/cat SID• 1/8 – 1/4 tablet!• Aim to get BP<170mmHg• Adjust dose as necessary

• ACE inhibitors• Not the most effective for systemic hypertension• May be used if amlodipine alone isnt effective

3. Proteinuria• Is a marker of glomerular damage

• Glomerulonephritis• Glomerular hypertension• Amyloidosis

• Proteins directly damage the renal tubules causing further nephron loss

• Can be measured via• Dipstick• Urine Protein Creatinine Ratio (UP:C)

• Gives quantitative measure of protein and significance• Prognostic indicator• Treatment decisions• Monitor response to treatment

Treatment of Proteinuria

• Renal diet

• ACEi (if UP:C >0.4)

Tests• Haematology

• Anaemia• Biochemistry

• Urea, Creatinine, K+, Na+, Ca+, Phosphate, Proteins• Urinalysis

• USG/dipstick, Sediment, Protein (UP:C), C&S• Systolic BP

Case 1 – 13 y MN DSH • Clinical signs

• PUPD, Lethargy, weight loss• Bloods

• Urea – 14.3, Creatinine – 178, phosphate normal

• Urinalysis• USG- 1.024, rest including

UP:C normal• Blood pressure

• 225mmHg

Treatment??

•Renal diet•Amlodipine 1/8 tablet SID

•Aim to get BP<170mmHg

Case 2 – 8y MN Xbreed • Clinical signs

• PUPD, lethargy, weight loss• Bloods

• Urea-16.2, Creatinine-290, phosphate 2.3 (<1.61)

• Urinalysis• USG-1.016, rest including

UP:C normal• Blood pressure

• 145 mmHg

Treatment???

•Renal diet and retest phosphate 4w later

•Phosphate 4w later – 1.97•Add in Ipakitine and aim for <1.61

Case 3 – 14y FN DSH• Clinical signs

• PUPD, Lethargy, weight loss• Bloods

• Urea-19.1, Creatinine-279, Phosphate – 2.7 (<1.61)

• Urinalysis• USG 1.019, UP:C- 0.8

• Blood Pressure• 160 mmHg

Treatment???

• Renal diet•ACE inhibitor

•But wouldn’t eat food so Ipakitine added to normal food•Retest bloods(inc Phosphate) and UP:C in 4w

QUESTIONS?