Chronic kidney disease

All of our bodies suffer the wear and tear of time. In people, our hearts are often our weakest organ. In dogs and especially cats, it is often their kidneys that wear out first.

There is a slow, but steady, loss of kidney function in all of our pets as they age but symptoms of kidney failure are generally not visible until there is less than 25% of kidney function left. Most people don’t realise that their pet’s kidneys are having trouble until they start noticing the symptoms of lack of appetite, excessive drinking and urination, weight loss, nausea, poor coat, hind end weakness, etc.

Dr Claudine Everson, a vet practising at Teva Veterinary Clinic in Somerset West kindly provides us with some useful information in this article.

Why did my pet’s kidneys fail?

In many cases, it is simply a matter of ageing-related deterioration, but some factors can contribute to kidney disease and cause early kidney damage. These include polycystic kidney disease (especially in Persian cats), hyperthyroidism (cats), chronic dental disease, autoimmune diseases, babesiosis, chronic skin infections, diabetes, and bladder stones.

What happens when my pet’s kidneys fail?

Kidneys keep your pet’s body free from the wastes that accumulate during metabolism. They are continually scrubbing the blood free of excess salts, water, and metabolites. Other vital functions include regulation of blood pressure, production of erythropoietin (needed for red blood cell production), and regulating the body’s calcium balance through the processing of vitamin D.

Why does my pet drink so much water and urinate so much?

The animal body is amazing in sensing when it has a problem. In an attempt to keep the body waste-free, your pet’s kidneys work overtime, using their insignificant remaining capacity to remove waste. This accounts for the excessive thirst and urination you see in your pet. For a while, this compensation keeps its body clean enough of wastes to function, but gradually the pet can’t consume enough water to keep its hydration balanced. Your pet then becomes dehydrated and waste levels rise, making them feel ill.

What are the signs of kidney disease?

The first sign that there is a problem is when your pet begins to drink water and urinate excessively. With time, your pet may begin to lose weight and become a more finicky eater. About this time, their energy levels tend to decrease as well. Their coats may lack the smoothness and lustre they once had, indicating a degree of dehydration.

In advanced kidney disease, pets will no longer eat. They often have nausea, retching, and diarrhoea. Their water intake decreases and they become dehydrated. These pets have developed uraemia or azotaemia, which is an intolerably high level of nitrogen-containing metabolic waste product in their blood.

How is kidney disease diagnosed?

Kidney failure is generally diagnosed by way of blood tests. Other tests that may be performed are urine testing, blood pressure, and ultrasound (if polycystic kidneys or stones are suspected).

How do I treat my pet’s kidney disease?

We cannot repair the damage that has been done to the kidneys, so the goal of our treatment is to support the function of the small percentage of the kidneys that is still healthy.

The most effective method we have of doing this is to decrease the amount of waste products (specifically phosphorous) that the kidneys have to filter. We do this by changing their diet.

Prescription diets designed for kidney failure are considerably lower in high phosphate proteins and sodium than ordinary pet foods. They also have added high levels of antioxidants, omega-3 and omega-6 fatty acids, and compounds like potassium citrate to counteract “over-acidity” in the body. These foods are designed to be highly palatable, easily crunched, and highly digestible to compensate for the fact that patients often have a reduced appetite.

It is important to increase your pet’s water intake as much as possible. This can be done by always ensuring that a lot of fresh water is available and by adding water to the food.

If your pet needs regular fluid therapies to treat dehydration, we might discuss giving subcutaneous fluids at home. If this is the case, have a look at this video for more guidance if needed.

Other treatments that may be added, depending on your pet’s stage of renal disease and test results are Vitamin B supplementation, ACE inhibitor medication, potassium supplementation, phosphate binders, antacid and anti-nausea medication, calcitriol, and fluid therapy.

How long will my pet live?

This is mainly dependent on the level of toxins in your pet’s blood and how much kidney function is remaining when they are first diagnosed. Pets with blood creatinine levels in stage 2 and early stage 3 ranges may do well for long periods (six months to two years, sometimes longer) but pets in late stage 3 and stage 4 have very little kidney function left and their response to treatment and quality of life is generally quite poor.

How often should I bring my pet with kidney disease to the vet?

The frequency of vet check-ups and tests required at the visits will vary depending on what stage of the disease your pet is in and how well they are responding to treatment. The maximum interval between visits should not exceed six months and they should be seen immediately if they are unwell.

More information

For more information click here.

Authored by Dr Claudine Everson (not a SAFREA member)

Proofread and Copyedited by Delilah Sao Joao (SAFREA member)

The views and opinions expressed in this article are those of the author and do not necessarily reflect the views of Safrea or its members.


2 Responses

  1. It hurts when pets get sick. It hurts more when we see them suffer. It hurts terribly when they die. At least now I have a pointer to recognise kidney disease early. Thanks.

    1. Absolutely Peter. I’m pleased to hear you found this article beneficial. At least when we have the knowledge, we’re able to do as much as we can to help our beloved pets and prevent suffering, where possible.

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