Chronic Renal Failure (CRF) in cats

The kidney is an excretory organ; it rids the body of nitrogenous waste. CRF is characterised by a decline in functional nephrons (the kidney is made up of many nephrons, which involve complex systems of tubules). When the nephrons are damaged they cannot filter waste efficiently and normal excretory functions are not maintained.

Symptoms:

• Dehydration
• Anorexia
• Lethargy
• Vomiting
• Weight Loss
• Anaemia
• Inappetence
• Polydipsia (excessive drinking) and Polyuria (increased urination) although these are more common in dogs with renal failure.
• Poor coat condition
• Stiff gait
• Sudden blindness (caused by hypertension)

Causes:

The causes of CRF are not yet fully understood but there are theories about several factors:

• Old age
• Genetics e.g. inherited PKD which affects Persians and Exotic Shorthairs
• Disease e.g. hyperthyroidism
• Dental disease (the bacteria present in the mouth may contribute to CRF)
• High blood pressure (this forces the nephrons to work harder)
• Vaccination (recent links between CRF and Feline Distemper vaccination)
• 30% of all CRF cats also have urinary tract infections (UTI’s)

Agravating factors:

• Dried food (however this is not thought to cause CRF)
• High protein diets (however this is not thought to cause CRF)
• Dehydration
• Trauma
• Acidifying diets
• Excess phosphorus and sodium
• Low Potassium
• Abnormally high or low blood pressure

Treatment:

• Rehydration
• Nutritional Management
• Management of hypertension (high blood pressure)
• Management of anaemia
• Appetite stimulants
• Management of nausea and vomiting (anti-emetics) – may encourage eating
• Management of hypocalcaemia
• Antibiotic treatment
• Screening and gene testing for genetic renal diseases such as PKD

Nutritional Management:

• Rehydration
• Nutritional Management
• Management of hypertension (high blood pressure)
• Management of anaemia
• Appetite stimulants
• Management of nausea and vomiting (anti-emetics) – may encourage eating
• Management of hypocalcaemia
• Antibiotic treatment
• Screening and gene testing for genetic renal diseases such as PKD

Feeding Advice:

* Most vets will agree that the single most important factor in CRF cats is to get them to eat. If they will not eat the prescription diets then feeding them what they like and will eat to avoid further weight loss is far more important that worrying about the protein and mineral content of the food.
* Some cats can suffer from Learned Aversion. Introducing a new diet to a very ill cat can result in the cat associating the new food with feeling unwell. They will then avoid the new food.
* A food low in fat and protein, as well as being highly digestible is recommended. In addition to feeding, water consumption can be increased by making sure the cat always has access to clean water or by adding additional water to the food.
* Daily feeding rates should be kept to a minimum. For advanced kidney failure the food can be fed sparingly (i.e. 30 % less than recommended) with cooked rice/porridge oats etc. Supplementing with carbohydrates allows a further reduction in the protein and mineral (phosphorus) content.
* It is essential that intake meets but does not exceed requirements. It is advisable to consult with your veterinary surgeon before dietetic use, as the diet will depend on the stage of the condition.

THE PROGRAMME

* All family members (and neighbours) must agree to cooperate by ensuring that the correct diet is followed i.e. no tit-bits, table scraps or other foods.
* Gradually introduce the new food to your cat. Gradual introduction, by allowing a slow change in intestinal bacteria, minimises the risk of digestive upset.
* Quantity of food. It is better to feed slightly less food, which will be properly absorbed rather than a large quantity, which could cause an upset.
* Success depends on feeding the right amount for each individual.

 

Alternative Treatments:

The following is from ‘Heal Your Cat the Natural Way’ By Richard Allport, B Vet Med, Vet M F Hom, MRCVS. Published by Mitchell Beazley 1997.

• Aromatherapy: Juniper
• Herbal Medicine: Alfalfa, Cornsilk, Cleavers, Parsley, Parsnip as infusions
• Chinese Medicine: 1 tsp of ginger or watermelon peel chopped per day

NB these may need to be used in conjunction with conventional treatment for CRF, not on their own.

 

Common pet health problems
John Burns Pet Health Management Programme