By Dr Joanna De Klerk
The kidneys are vital organs, which have many different roles within the body. This is why if your four-legged friend has kidney disease, all sorts of symptoms (which maybe seem unrelated) might appear. Caring for pet with kidney disease requires the help of your vet, but there also are plenty of things you can do at home to help improve the quality of life for your furbaby.
What is the Purpose of the Kidneys?
The kidneys are a pair of organs which are involved in excreting things out of the body. This includes toxins, waste products from the metabolism process, excess water and nutrients which are not needed. This helps to keep the bloodstream in a balanced harmony without anything excessive present.
They also play a vital role in controlling blood pressure through releasing a hormone called renin. This sets in motion a chemical pathway which ends up affecting the diameter of the blood vessels, and therefore the pressure of the blood inside.
Finally, they play a role in blood production. If more red blood cells are needed, the kidneys release a hormone called erythropoietin, which stimulates the bone marrow to produce more cells.
So it’s clear that kidneys are pretty amazing (and extremely vital) organs!
Acute Renal Failure and Chronic Kidney Disease
If your pet develops kidney disease, it can happen either acutely or chronically. In other words, quickly, or over a long period of time. Dogs have more tendency to develop acute renal failure (ARF), whereas cats are more likely to develop chronic kidney disease (CKD). However, it can be the other way around too.
When kidneys deteriorate and start to show signs of disease, they are often already very damaged. In fact, a kidney can lose up to 75% of its function before any symptoms become apparent at all. That’s why it’s important to try to prevent kidney disease, by minimising toxin exposure, ensuring adequate water intake and feeding a high-quality balanced diet throughout your pet’s life.
Acute renal failure tends to happen after a sudden insult to the kidneys. Commonly this is poison ingestion, but it can also be caused by things like heatstroke, severe dehydration, kidney infections, medication overdose and snake bites.
Chronic kidney disease, on the other hand, is usually caused by the kidneys wearing out, and commonly associated with age-related change. However, genetics, breed predisposition, and lifestyle also play a big role in the development of CKD.
Regardless of whether your pet has ARF or CKD, they are likely to exhibit some of the following symptoms:
- Excessive thirst
- Excessive urination
- Nausea
- Mouth ulcers
- Anaemia, which can cause tiredness
- Poor appetite
- High blood pressure, which can lead to blindness
Nutrition for Kidney Disease
Nutrition plays a vital role in the management of kidney disease (both ARF and CKD). The kidneys need to filter out waste products from the metabolism process, and a high quality diet will reduce those waste products. In addition to that, electrolytes and water often become imbalanced when the kidneys don’t work well, and specific diets can help to correct that too.
The following things should be considered when choosing a kidney-friendly diet:
- Protein: Protein is a vital building block for growth and regulation of many body functions. It is used to make hormones, muscle tissue and cell walls. However, any protein left over which is not needed is then converted into urea, and removed by the kidneys. If the protein quantity in the diet is lower than usual, but the protein is high-quality, then there is less waste. This means there is less urea build up, resulting in less nausea and mouth ulcers. Egg and meat proteins are of a much higher quality than cereal grain protein.
- Phosphorus: The kidneys play a vital role in managing the level of phosphorus in the blood. But when they are damaged, the level of phosphorus increases in the bloodstream, which in turn leads to other derangements in other electrolyte levels. Therefore kidney-friendly diets are usually low in phosphorus.
- Salt: Sodium, potassium and magnesium levels are all affected by kidney disease, and therefore diets are usually low in salt.
- Palatable: Protein-restricted diets are usually not very tasty, which is a big problem if your pet is already feeling nauseous. Cats in particular are fussy little creatures when it comes to food. So kidney-specific diets usually have some ingredients in which improve the palatability.
A study in 2002 demonstrated that dogs with kidney disease which were fed a kidney-friendly diet had a better quality of life, and survived at least 13 months longer than those fed normal dog food. In dog terms, that could be about 10% extra of their lifetime!
There have also been similar studies for our feline friends, which show similar results.
Specialist foods are available for both dogs and cats, and you should consult your vet if you need any advice on dietary management of this condition.
Home Care for Pets with Kidney Disease
There’s plenty you can be doing at home to ensure that your furry friend gets the best care when they are suffering from kidney disease.
Monitoring disease progression closely plays a huge role in the management of kidney disease, and it is easy to do from home. It is worth creating a diary where you can record your pet’s food and water intake daily, as this can easily go unnoticed if you aren’t actively keeping an eye on it. With the water, measure what you put in the bowl over 24 hours, and at the end of the day, subtract what is left in the bowl. You can do the same for food if your pet is a grazer, and if your furbaby eats regular meals, it’s a bit easier to notice if any food is left. Let your vet know if your pet is drinking more than usual, or eating less than usual.
In addition to this, if your pet has advanced kidney disease, he might occasionally need fluid therapy to flush out the high levels of urea in the bloodstream. Intravenous therapy is the most effective, but if your pet gets extremely stressed in the hospital and isn’t in a critical position, you can ask your vet to show you how to inject fluids under the skin at home. This might be daily or weekly, depending on how severe the kidney disease is.
Finally, pets with kidney disease will have some good days and some bad days. It’s normal for their symptoms to fluctuate. So when your pet has a bad day, keep him warm, well rested, well fed (if he’s not feeling nauseous), and make sure he feels extra-specially loved.
Veterinary Therapy for Pets with Kidney Disease
Your vet will want to regularly check on your pet to ensure their kidney disease is being managed appropriately. This will usually involve blood tests, to check for whether the urea, creatinine, SDMA and electrolytes are increased in the blood.
Your vet may also prescribe some medications to improve kidney function and decrease unpleasant symptoms associated with kidney disease. These might include:
- A phosphate binder – this binds phosphorus in the intestines to prevent it being absorbed into the blood.
- A medication to decrease nausea – there are several different types of anti-nausea medications, and many will also work to increase appetite.
- A medication to stimulate bone marrow to produce red blood cells – a synthetic form of erythropoietin can be used short-term to stimulate the bone marrow.
- A medication for high blood pressure – several different options are available to help reduce blood pressure, which either act directly at the kidneys, or elsewhere in the circulatory system.
- A medication to improve kidney filtration – improving the ability of the kidneys to filter blood will help slow down further damage.
You might find that your pet is prescribed multiple medications, so a top tip is to have a pill container, so you can remember to give the tablets at the correct time. Be sure to follow your vet’s instructions carefully. For example, if it says twice daily, try to make the doses exactly 12 hours apart. Diligent care will significantly improve your furbaby’s quality of life.
Take Home Message
Kidney disease can occur as acute renal failure (ARF) or chronic kidney disease (CKD). Whichever the result, it is never pleasant for your furry friend, however there is a lot you can do to improve your pet’s prognosis. There are many medication options and home care treatments you can try, but the most important treatment of all is feeding the correct diet.
