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Chronic renal failure care

When it's too late... Your pet needs even more attentive care! Manhattan Veterinary Hospital/Dr David Tan


When it's too late... Your pet needs even more attentive care!

The kidneys are quite important organs. Their main purpose is to regulate water content, electrolytes and excrete the body's wastes. When kidney functions start to decline, it causes "renal insufficiency", or what people call "renal failure." There are many causes of renal failure in cats and dogs including poisoning, infection, kidney stones... All of these may cause damage to kidney functions.

Renal failure can be classified into either acute renal failure or chronic renal failure. The main difference between the two is the time-frame. If an animal's kidneys suffer serious harm and can't function properly anymore, the metabolic wastes build up in the body instead of being filtered. When the substances are not filtered out by the kidneys and remain the blood, the result is "uremia" and acute renal failure.

If a dog or cat with acute renal failure receives professional medical treatment or recovers on its own, even though they may not die, most of the kidneys themselves may no longer function and become fibrous. Chronic renal failure is then what happens next.

Chronic renal failure causes and symptoms

"Chronic renal failure" means less than 25% of the kidneys are functioning. In other words, over 75% of the kidney functionality has been irrevocably destroyed; the lower the percentage of kidney function still left, the higher the level of blood urea nitrogen (BUN) that can't be excreted and is building up in the blood. The dog/cat is then in even more danger.

The most obvious clinical symptom of chronic renal failure in cats and dogs is drinking large amounts of water and frequent urination. The kidneys also produce a substance called "Erythropoietin" (EPO) that tells the bone marrow to produce blood cells. When kidney function deteriorates, so does the amount of EPO. When the number of red blood cells is low it triggers "anemia", leading to nausea, pale mucous membranes and swaying while walking.


Substances to watch out for in daily diet

Pets with chronic renal failure will drink large amounts of water and urinate frequently. This may lead to a deficiency or excess of certain ionic substances in the pet's body. If acute renal failure has been brought under control and has transitioned to chronic renal failure, "diet" and "fluid" control must be carried out to reduce the burden on the kidneys.

Pets with chronic renal failure usually suffer from loss of Potassium ions and excessive levels of Phosphate ions. Particular attention must be paid to the replenishment of Potassium ions and control of Phosphate ions in their daily diet to avoid stressing the kidneys.

In terms of food intake, pet owners can choose prescription food for dogs and cats with chronic renal failure. If they wish to prepare their pet's food themselves, they must pay attention to the following: (1) Keep the intake of Sodium ions low; (2) add Calcium ions and control the intake of Phosphate ions; (3) replenishment of Potassium ions. The method of replenishment and the dosage will depend on the pet's condition. Seeking the professional advice of a vet is recommended.

Avoid triggering complications related to hypertension

The kidneys of pets with chronic renal disease are already under a great deal of stress. In addition to providing them with plenty of good quality water, owners may also wish to consider "subcutaneous transfusions" to help the pet excrete the body's waste products more quickly.

In addition, particular care must be taken to avoid hypertension in dogs with chronic renal disease; hypertension will also damage kidney function; to prevent hypertension, the pet must be taken regularly to the vet for blood pressure monitoring. The amount of Sodium ions in the diet will also have an impact on hypertension so owners should seek advice from the vet.

Steer clear of kidney poisons in the environment

Apart from controlling everyday diet, care must be taken to avoid exposing the family pet to poisonous substances that stress the kidneys even more.

Most pet owners may be unaware of how many substances in our everyday lives are deadly poisons to pets. Insecticides, mosquito coils, disinfectant... Be sure to keep pets clear of all chemicals containing pyrethroids. When you take your pet to the clinic for treatment you must also tell the vet about the pet's renal failure, and remind the vet to not use chemicals that are toxic to the kidneys and may cause kidney damage.

"Grapes" and "Lilies" are also common causes of poisoning in pets. Pet owners must be very careful to avoid tragic mistakes. Heartworm will also lead to renal failure. Be sure to give your pet heartworm prevention medication on a regular basis when summer approaches.

Best time for transfusions

As for ways of treating renal failure, kidney transplants for pets have been conducted overseas and the survival rate is between 40 ~ 50%. Currently, the main treatments used by local vets are "transfusion" and "peritoneal dialysis" which has drawn a great deal of attention lately.

From a dialysis perspective, when a cat or dog is in the acute stage of acute renal failure then dialysis can be used to reduce the level of toxins in their body. Once their condition improves or changes to chronic renal failure, dialysis can be suspended to be replaced by dietary control and medication.

When a pet is in the chronic renal failure stage, it needs dietary control, medication, EPO injections, and regular visits to the vet for blood tests to check for high readings. If the situation starts deteriorating again afterwards then it's time to resume dialysis.

Hemodialysis and Peritoneal dialysis

Generally speaking, hemodialysis refers running a tube from the jugular vein to the heart and pumping blood containing poisons to an artificial kidney for dialysis. The clean blood is then pumped back into the heart and other parts of the body. Peritoneal dialysis involves pumping clean dialysate into the cat/dog's abdominal cavity. The toxins are filtered out of the peritoneum and then pumped out of the abdominal cavity.

All types of dialysis use diffusion to transfer the toxins in the blood over to the dialysate. Cleaning the blood helps the sick dog/cat eliminate the toxins in its body.

Some people might wonder: if a cat/dog with renal failure's kidneys are already damaged, won't giving it water put the kidneys under even more stress?

In reality, since not much of the dog or cat's kidney functions are left and only a very limited amount of toxins can be excreted, transfusions or hemodialysis/peritoneal dialysis are all aimed at helping them get rid of the toxins in their body instead of allowing it to build up.

What has happened has happened. For pets that managed to survive and now have chronic renal failure, pets should treasure their time with their pets even more. With proper care and professional vet advice, they should can still have a lot of fun and laughter with their pets.

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