Caring for Cats with Kidney Disease: A Complete Guide
By Evelyn Harcourt
januari 20, 2025 - 1 min readIt is estimated that around 10% of all cats live with kidney disease. The majority of these cats will be middle-aged and older, and around 80% of those over the age of 15 will be affected.
Feline renal disease tends to be slowly progressive, with cats regularly living for several years after diagnosis. Along with routine veterinary checks, there is a range of things you can do from home to help ensure your cat thrives after diagnosis.
What is Kidney Disease in Cats?
The kidneys work to filter the toxins from the blood, as well as to regulate fluids and maintain normal blood pressure and red blood cell levels. When the kidneys are diseased, they can no longer perform these functions, and an affected cat will develop some tell-tale signs.
Types of Kidney Disease in Cats
Kidney disease in cats is broadly divided into two categories: Acute and chronic. Acute kidney disease is less common. Signs come on quickly, and they are more often seen in younger cats. Causes can include a urinary blockage or a toxin ingestion.
Much more commonly, we will be dealing with chronic kidney disease. This is when the kidneys slowly lose function over months and years. In these cases, symptoms progress so insidiously that they are usually overlooked in the earlier stages.
Causes of Kidney Disease in Cats
Often, feline kidney disease is idiopathic, which means we aren’t sure what causes it. In practice, most patients will not know the reason for their kidney disease, as a specific diagnosis is not routinely pursued in senior patients.
Let’s take a look at the most common causes of feline kidney disease, both acute and chronic.
Natural Aging and Organ Deterioration
Given that chronic kidney disease mostly affects cats in their second half of life, it is expected that the culprit would frequently be deterioration of the kidneys over time. Sadly, as the body ages, the organs inevitably begin to function ineffectively.
Exposure to Toxins
Toxin exposure will generally cause acute kidney disease. This can progress to chronic kidney disease if not treated successfully. Lily flowers, certain human medicines, and anti-freeze are some of the most common causes of toxic renal failure.
Generally, these patients will not be underweight, and their signs come on rapidly within just one or two days. They may have a history of being near toxins (for example, if the owner has a vase of lilies in the home).
If you suspect your cat has been exposed to a renal toxin, you must contact your local emergency vet right away. For most cases of poisoning, time is of the essence.
Dehydration
Dehydration can lead to reduced circulation and a buildup of toxins within the kidneys. In severe cases, this can potentially cause kidney damage. Preventing dehydration in very unwell patients is usually achieved by providing an intravenous fluid drip, especially if they are vomiting and off their food.
Infections
Pyelonephritis is the name we give to bacterial infections (such as E. coli or Klebsiella) that affect the kidneys. Usually, these bacteria have traveled up from the urinary tract. There is a risk of the infection spreading around the body, so some cats will decline quickly.
Certain viral infections, such as FIV and FIP, are known to cause glomerulonephritis and kidney disease in cats. Vets may consider testing for these common infections when presented with a cat with recently developed renal disease.
Genetic Predispositions and Breed-Specific Risks
Thanks to their genetics, certain breeds are more prone to kidney disease. Persians and Abyssinians, for example, are predisposed to developing renal amyloidosis. Polycystic kidney disease is seen more in breeds such as the Persian, British Shorthair, and Scottish Fold.
Being aware of these predispositions is key, as breeders can screen their cats and avoid breeding from those who are affected. It is also useful for vets to know, so they can prioritize investigations for specific conditions in those who are predisposed to them.
Underlying Health Conditions
Medical conditions, including diabetes, high blood pressure, hyperthyroidism, and certain cancers may all make kidney disease more likely. For this reason, it is sensible to evaluate the patient as a whole when they present to the clinic with chronic kidney disease (CKD).
Dietary Factors
Diets higher in phosphorus, sodium, and protein may lead to kidney disease or at least exacerbate it. While dry diets don’t cause kidney disease, they can mean the cat is poorly hydrated, worsening urinary tract issues.
How to Recognise Symptoms of Kidney Disease
The symptoms of kidney disease are not specific to this condition but can certainly make a vet suspicious when several symptoms are present in an older cat.
The more common signs of chronic renal disease include:
- Polyuria/Polydypsia, meaning an excessive thirst and urination
- A reduced appetite
- Weight loss
- Muscle wastage
- Nausea and persistent vomiting
- Mouth ulcers
- Diarrhoea
- A dull coat
- Pale gums due to anaemia
- Lethargy and a reduced interest in things around them
How to Diagnose Kidney Disease in Cats
When you bring your cat into the clinic, your vet will be suspicious of kidney disease after listening to your cat’s clinical history and assessing them. As it is such a common condition, it is always going to be on your vet’s radar.
Your vet may notice that your cat’s kidneys are shrunken and irregular when felt from outside the body. They may also pick up on weight loss when compared to the last few years.
To confirm the diagnosis, your vet will run a urine and blood test. In some cases, they may also run further tests, such as a blood pressure measurement and imaging of the urinary tract.
Those with chronic kidney disease will typically have raised Blood Urea Nitrogen and Creatinine levels, as well as high SDMA levels and non-regenerative anaemia.
High phosphorus levels may also be seen. The cat’s urine will be dilute, and some cats will have evidence of protein, blood, or bacteria in it.
What Are the Treatment Options for Cats with Kidney Disease?
Though we cannot cure chronic kidney disease, it can be managed. Indeed, with the right interventions, patients can live for months to years and enjoy a good quality of life.
Dietary Management
The cornerstone of managing kidney disease is diet. These patients should be quickly swapped to a renal-supportive diet that contains high-quality proteins that are easily digestible and not present in excessive quantities. Diets should also be high in Potassium and B vitamins and low in phosphorus.
Ideally, these cats would be fed on a wet diet. Owners can also add water to meals and encourage water drinking through the use of water fountains, rehydration solutions and cat soup.
Medications and Supplements
Certain dietary supplements, such as Phosphorous binders, B vitamins and probiotics, may be recommended by your vet. These are usually given alongside your pet’s meals.
Medications such as ACE inhibitors and Angiotensin Receptor Blockers can help to reduce hypertension and prevent protein from being lost in the urine.
As kidney disease progresses, cats need more interventions and medicines. This can include antacids, anti-nausea medicine, and appetite stimulants, which help combat the effects of toxin buildup.
Hydration and Fluid Therapy
In the later stages of the disease, cats are less able to maintain their own hydration. They may be admitted for a few days of intravenous fluid therapy, or your vet might discuss providing subcutaneous fluid from home.
Home Care and Lifestyle Tips for Your Cat
As an owner, the main way you can help your cat is by ensuring it is fed an appropriate diet as soon as it is diagnosed. Encouraging plenty of fluid drinking is also important to help keep the kidneys flushed.
Be sure to provide any medicine your vet has prescribed. If you are having trouble giving the medicine, talk to your vet about options such as pill poppers and pill pockets. If your cat refuses its meals, it can help warm up the food to release the aromas and flavours.
Monitor your cat closely, noticing any changes in its appetite, urination, and energy levels. Be sure to bring it to your local clinic regularly for checkups. This way, any medicine or interventions it would benefit from can be started promptly.
Get More Advice On Feline Kidney Disease
You are always welcome to contact us to discuss your cat and their kidney disease, or if you're concerned, your cat is showing symptoms that could be consistent with renal failure.
Our staff are here to ensure your cat gets the best care.
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