CRD nutrition Flashcards
Clinical relevance of CKD
- CKD is one of the most common diagnoses made in clinical practice
- Most affected cats are middle aged or older and studies suggest that an estimated third of cats over the age of 10 years suffer from this condition
What makes a therapeutic diet for CKD?
- protein restriction
- phosphate restriction
- high palatability and calorie content
- potassium and B vitamin supplementation
- non-acidifying
- omega 3 fatty acids
- diet should be introduced gradually
- renal prescription diets are esp proven in cats with stage 3 and 4 renal dz
Common complications for CKD
- azotaemia
- uraemia
- metabolic acidosis
- dehydration
- electrolyte disturbances
- hypertension
- loss of muscle mass and poor BCS
- accumulation of drugs and toxins
- renal secondary hyperparathyroidism
- anaemia
Why include dietary therapy into treatment plans?
- positive impact on quality and length of life in pts with CKD
Wet or dry food?
- renal prescription diets are formulated in wet and dry forms
- dry food does still contain the useful modifications - any renal diet is preferable to standard cat food
- wet diet preferable to help prevent dehydration which may lead to hospitalisation
Importance of palatability and calorie density
- calorie density is vital
– we want to maintain normal BCS and muscle mass
– pts with CKD often have significant weight loss - palatability is key
– cats with CKD often have a poor appetite - high fat and calorie content aids palatability
What to do for the inappetent CKD pt
- consider supportive nursing to encourage eating
– hand feeding
– offering slightly warmed food and sitting with the cat
– stroking whilst it eats - appetite stimulants
- anti-emetics
- H2-blockers
- don’t overwhelm with food choices
- don’t leave food in enclosure for extended periods
What is the significance of cats being obligate carnivores?
- cats require more protein than dogs or other omnivores but protein restriction has been recommended for pts with renal dz for decades
Cats in normal health
- adapted to metabolise a natural diet that’s extremely high in protein and low in carbs without developing ketonemia
- they readily use protein and amino acids to generate their glucose needed by their cells
Cats in ill health
- when protein needs aren’t 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, as protein catabolism is increased and synthesis is decreased leading to loss of muscle mass
How is the biological value of protein determined?
- how readily the amino acids are broken down and used by the body
Use of protein restricted diets in cats
- protein restriction and feeding of high biological value protein can help manage clinical signs
- accumulation of protein breakdown products is 1 of the causes of uraemia clinical signs
- protein restriction diets help reduce the severity of azotaemia
- reduction of associated CS: nausea, vomiting, anorexia, lethargy
Hyperphosphataemia in CKD pts
- CKD pts are vulnerable to electrolyte disturbances as regulation depends on effective glomerular filtration and excretion
– hyperphophataemia is a common complication - hyperphosphataemia is a major contributor to the development of renal secondary hyperparathyroidism
- it is believed to be damaged to the kidneys, contributing to continued and worsening renal injury
- associated with poor prognosis
Benefit of phosphate restriction
- helps delay progression of CKD
- reduces likelihood of secondary hyperparathyroidism
- pt will feel better
- pt may live longer
Omega 3 fatty acids - potential benefits and recommendation for CKD pts
- increase renal blood flow to minimise hypoxic damage and potentially reduce inflammatory mediators
- useful for all stages of CKD
Water soluble vitamins - potential benefits and recommendation for CKD pts
- supplementation of vitamin B to compensate for depleted levels due to CKD related polyuria
- useful for all stages of CKD
Sodium - recommendation for CKD pts
- Avoid excess however there is no evidence that restriction is beneficial
Fibre - potential benefits and recommendation for CKD pts
- 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 pt lifestyle
Non-acidifying diet - potential benefits and recommendation for CKD pts
- 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
Potassium & CKD pts
- cats with CKD are vulnerable to losing excessive amounts of potassium in the urine
- hypokalaemia is often associated with CS such as malaise and inappetence
- more marked hypokalaemia is associated with severe muscle weakness and ventroflexion
How to transition to a renal diet
- long term aim
– introduce slowly, can be counter productive if cat is in the hospital or clinical unwell, consider using a feeding tube - introduce early
– before progression of CKD - education of owners
– welfare implications and benefits on quality of life, increase compliance and understanding - wet food is preferred to dry
– increased water content - a standard commercial senior diet can be useful when cost is an issue esp in the early stages of CKD
Stage I CKD
- appearance normal
Stage II CKD
- may be an increase in drinking and urination
Stage III CKD
- frequent drinking
- frequent urination
- reduced appetite
- weight loss
- dehydration
- vomiting
- dull unkempt coat
- weakness
Stage IV CKD
- possible mouth ulcers
- blindness
- severe vomiting
- diarrhoea
- refusal to eat
- dehydration
- weakness
- lethargy
What is the initial starting point for initiating nutritional support in hospitalised pts
- RER = BW^0.75 x 70
