Dietary management in chronic kidney disease

Question 1

When are renal diets helpful in cats?

Answer 1

Renal prescription diets are especially proven for cats with stage 3 and 4 renal disease

Question 2

what are the characteristics of an ideal renal diet?

Wet or dry food?

Answer 2

• Highly palatable since most cats with CKD have a reduced appetite
• Formulated to help compensate for the cat’s reduced renal function
• Formulated to prevent and/or manage common and important complications that are seen in patients with CKD
• Support the normal function of the kidneys
• High Calorie density – to maintain normal BCS and muscle mass.

Wet vs dry:
- renal prescription diets are formulated in dry and wet forms
- Wet diet preferable to help prevent dehydration which may lead to hospitalisation
- Dry food does still contain the useful modifications- any renal diet is preferable to standard cat food

Question 4

Why is protein needed even with CKD?

Answer 4

In ill health cat does not eat - when protein needs are not met, cats lose lean body mass, catabolising muscle and other lean tissues to meet the needs for protein turnover and ongoing metabolic needs

This effect may be worsened in cats with CKD, because protein catabolism is increased and synthesis is decreased leading to loss of muscle mass

The benefits of protein restriction on disease progression rate have not yet been demonstrated in cats. However, protein restriction and the feeding of high biological value protein can help manage clinical signs

Question 5

how is the biological value of protein determined?

Answer 5

Thebiological value of protein is determined by how readily the amino acids are broken down and used by the body

Question 6

why is phosphate restriction important with CKD?

Answer 6

CKD patients are vulnerable to electrolyte disturbances as regulation depends on effective glomerular filtration and excretion. Hyperphosphataemia is a common complication

• Hyperphosphataemia is a major contributor to the development of renal secondary hyperparathyroidism
• it is believed to be damaging to the kidneys, contributing to continued and worsening renal injury
  ◦ associated with a poor prognosis

Therefore phosphate restriction will –
* Help delay progression of CKD
* Reduce the likelihood of secondary hyperparathyroidism
* The patient will feel better
* The patient may live longer

Question 8

What are the benefits and reccomendation with omega-3 fatty acids and renal disease?

Answer 8

• Increase renal blood flow to minimise hypoxic damage and potentially reduce inflammatory mediators
• Useful for all stages of CKD

Question 9

What are the benefits and reccomendation of water soluble vitamins and renal disease?

Answer 9

• Supplementation of vitamin B to compensate for depleted levels due to CKD related polyuria
• Useful for all stages of CKD

Question 10

What are the reccomendation with sodium and renal disease?

Answer 10

• Avoid excess however there is no evidence that restriction is beneficial
  (Avoid excess in any diet)

Question 11

What are the benefits and reccomendation with fiber and renal disease?

Answer 11

• nitrogenous waste products, such as urea, are bound in the bowel and eliminated with the faeces rather than being absorbed into the body
• Take into account patient life style

Question 12

What are the thoughts about acidifying diets and renal disease?

Answer 12

• Helps prevent development of metabolic acidosis, a common CKD complication. Maintaining a normal acid base can also help prevent hypokalaemia
• Useful for all stages of CKD

Question 13

what is the relation of renal disease and potassium, what are the clinicla signs?

Answer 13

• Cats with CKD are vulnerable to losing excessive amounts of potassium in the urine.
• Hypokalaemia is often associated with clinical signs such as malaise and inappetence. More marked hypokalaemia is associated with severe muscle weakness and ventroflexion