Kidney problems in dogs and cats: recognition, diagnosis and support

Kidney problems, particularly chronic kidney failure (Chronic Kidney Disease or CKD), are among the most common conditions in older dogs and cats. The kidneys play a vital role in the body: they filter waste products from the blood, regulate fluid and mineral balance, produce hormones, and help maintain blood pressure. Because the kidneys have a huge reserve capacity, they can compensate for damage for years without any clear complaints becoming visible. Often, the first symptoms do not appear until about 70-75% of kidney function has been lost. This makes kidney failure a true "silent killer".

Acute versus chronic kidney failure

• Acute kidney failure: Comes on suddenly, often due to poisoning, infection, obstruction, or severe dehydration. With rapid treatment (such as an IV), recovery is sometimes possible.
• Chronic kidney failure (CKD): Develops ins idiously and is irreversible. In cats, it affects about 30% of animals older than 15 years. In dogs, it occurs mainly in seniors.

Symptoms to watch for

Common signs include:

• Increased drinking and increased urination (polyuria/polydipsia)
• Reduced appetite or food aversion (due to nausea)
• Weight loss and thinning
• Vomiting and/or diarrhea
• Bad breath (urea smell)
• Lethargy and less active behavior
• Poor coat condition

These complaints are often subtle at first. Regular health checks at the veterinarian (blood and urine tests) are essential for senior animals.

Diagnosis: understanding blood and urine values

The veterinarian checks, among other things:

• Creatinine and urea: Elevated values indicate reduced kidney function.
• SDMA: An earlier and sensitive marker for kidney damage.
• Phosphate: Often elevated and must be strictly controlled.
• Urine protein-creatinine ratio: Indicates protein loss.
• Additional: Blood pressure, ultrasound, and sometimes other tests.

Note: An elevated creatinine does not always mean chronic kidney failure; dehydration or other factors can also play a role.

Treatment and prognosis

Treatment focuses on slowing down the decline, relieving the kidneys, and maintaining quality of life:

• Sufficient fluids (IV for acute, subcutaneous for chronic).
• Medication for nausea, blood pressure reducers, and phosphate binders if necessary.
• Nutrition as the cornerstone of therapy.

The prognosis depends on the stage, the cause, and the response to treatment. Early intervention makes a big difference.

The role of nutrition in kidney patients

Nutrition is crucial in CKD. From IRIS stage 2, it is recommended to switch to a modified diet with:

• Restricted phosphorus (the most important factor in slowing progression)
• High-quality protein, but in limited amounts
• Low sodium
• High moisture content
• High palatability (against food aversion)

Supportive nutrition

Dry food

BF Petfood does not offer a dedicated clinical kidney diet, but it does offer excellent Senior formulas that are explicitly suitable for animals with sensitive kidneys and older animals. These food lines have a reduced protein, phosphorus, and sodium content, high digestibility, and focus on palatability.

• For dogs: Senior, Senior mini (both kibble) and Pressed Senior (gluten-free) – suitable for dogs with sensitive kidneys or bladder. Contains various protein sources such as chicken, beef, and salmon.
• For cats: Senior – Ageing (kibble) – developed for older cats and cats with sensitive kidneys. With chicken, fish, duck, salmon, and salmon oil.

Wet food

Wet food is particularly valuable because of the high moisture content, which helps prevent dehydration and supports the kidneys. BF Petfood recommends combining wet food with the Senior dry food. Specifically recommended:

• BIOFOOD Organic Beef - Menu for cats: Low protein content of good quality and high moisture content. Ideal for picky cats with mild kidney problems.
• BIOFOOD Organic Turkey - Menu for dogs: Low protein and phosphorus content of good quality and high moisture content. Ideal for picky dogs with mild kidney problems.

Practical tips

• Provide several small meals per day.
• Warm the wet food slightly or mix it with warm water for more aroma.
• Ensure constant access to fresh water (e.g., with a drinking fountain).
• Vary between dry and wet food for better acceptance.
• Monitor weight and appetite closely.

Prevention and monitoring

• Annual or semi-annual checks for senior animals.
• Good hydration and a healthy weight.
• Extra alertness for breeds with an increased risk.

NOTE! For chronic kidney failure, a special clinical veterinary kidney diet (Renal diet) is the best choice. These diets are specifically developed for kidney patients and offer the strictest restriction of phosphorus and protein. Always consult your veterinarian about which option best fits the stage and individual needs of your pet.

Summary

Kidney problems are a silent killer, but with a timely diagnosis, good medical care, and supportive nutrition such as the Senior formulas from BF Petfood or, if necessary, a clinical kidney diet, many dogs and cats can enjoy a good quality of life for years to come. In the case of chronic kidney failure, a special clinical veterinary kidney diet is the best choice. If you suspect kidney problems, always have a full blood and urine test done by the veterinarian first. Consult your veterinarian for personal advice and diagnosis. Diet choice is customized work.

For more information, email: info@bfpetfood.nl or use the contact page.