Kidney stones in cats can be a painful and serious issue, often leading to discomfort and health complications. Just like humans, cats can develop these small, hard deposits in their kidneys or urinary tract, which can interfere with normal bodily functions. In this article, we’ll explore everything you need to know about kidney stones in cats, from recognizing the signs to treatment options, and prevention strategies.
What are kidney stones in cats?
Kidney stones, also known as nephroliths, feline urolithiasis, or urinary stones, are hard mineral deposits that form in the kidneys. These stones are made up of various minerals and salts, which can crystallize and stick together.
Kidney stones are much different than bladder stones and can cause different symptoms and complications in cats.
What causes kidney stones in cats?
There are various reasons why cats may develop kidney stones. Some of the most common causes include:
- Dehydration: Cats who don’t consume enough moisture can have concentrated urine, which makes it easier for minerals to crystallize and form stones.
- Diet: A diet high in certain minerals such as calcium or oxalate can increase the risk of developing kidney stones.
- Urinary tract infections: Bacteria or inflammation in the urinary tract can lead to an increased risk of stone formation.
- Genetics: Breeds like Siamese and domestic long-haired cats seem to be more likely to develop a specific type of kidney stone made of calcium oxalate.
- Hypercalcemia: This condition occurs when there is too much calcium in the bloodstream, which can increase the risk of calcium-based kidney stones, particularly with struvite stones.
What are the concerns for cats with kidney stones?
While some kidney stones may remain asymptomatic, others can lead to significant health concerns for your cat.
These complications can range from immediate discomfort to long-term health issues:
- Urinary blockages/obstruction: Kidney stones can obstruct the flow of urine, either within the kidney itself or in the ureters (the tubes that carry urine to the bladder). This urinary blockage can cause severe pain and, if not addressed promptly, can become a life-threatening emergency.
- Pyelonephritis (kidney infection): Nephroliths can serve as a breeding ground for bacteria, leading to infection within the kidneys. This can cause further damage to the renal tissue and requires prompt veterinary attention.
- Pain and bloody urine: Kidney stones can irritate the sensitive tissues of the urinary tract, resulting in pain, particularly during urination. This discomfort may also be accompanied by blood in the urine (hematuria).
- Chronic Kidney Disease (CKD): In some cases, the presence of nephroliths can contribute to the development or progression of chronic kidney disease. While the exact relationship between nephrolithiasis and CKD is still under investigation, studies have suggested a potential association between the two conditions.
It's important to note that not all cats with kidney stones will experience these issues, and the impact can vary greatly from one cat to another.
I recommend regular check-ups with your veterinarian, which can help catch and address any problems early.
What are the symptoms of kidney stones in cats?
Many cat owners are surprised to learn that kidney stones often don't cause noticeable symptoms, especially in the early stages.
However, there are some signs you can watch for:
- Increased urination (polyuria): Your cat may need to urinate more frequently than usual or have larger urinations.
- Increased thirst (polydipsia): You may observe your cat drinking water more often.
- Digestive issues: Watch for vomiting or loss of appetite.
- Weight loss: Unexplained weight loss can be a sign of various health issues, including kidney stones.
- Discomfort: Your cat might show signs of abdominal pain or discomfort.
- Behavioral changes: Changes in behavior, such as lethargy, irritability, or disinterest in usual activities, may be observed.
- Body posture: Some cats may arch their backs due to pain.
- Blood in urine (hematuria): You might notice your cat's urine is pink or red-tinged.
It's important to note that these symptoms can also be signs of other health issues, including urinary tract infections or kidney disease. Additionally, some cats with kidney stones might not show any symptoms at all, especially if the stones are small or not causing blockages.
How are kidney stones diagnosed in cats?
The first step in diagnosing kidney stones involves a comprehensive physical examination of your cat. We'll gently palpate their abdomen to assess any signs of discomfort or changes to the size of the kidneys. We'll also discuss your cat's medical history and recent symptoms to gain a clearer understanding of their condition.
Next, we'll likely recommend abdominal X-rays. These images allow us to visualize the kidneys and identify any visible stones. X-rays provide valuable information about the size, number, and location of the stones.
Finally, we'll collect a urine sample for urinalysis. This test examines the urine for the presence of blood, crystals, infection, and other abnormalities that may indicate kidney stones or other underlying conditions.
Based on the findings from these initial tests, we may recommend additional diagnostics, such as blood work or ultrasound, to gain a more comprehensive understanding of your cat's health and determine the most appropriate treatment plan.
What are the treatment options for cats with kidney stones?
Not all kidney stones require treatment or intervention. Some may remain stable and asymptomatic, necessitating only regular monitoring.
However, in cases where the stones are causing obstruction, increasing in size or number, leading to recurrent infections, or contributing to pain, hematuria, or declining kidney function, treatment becomes necessary. Here are some of the options available:
1. Medical management
- Dietary modification: For struvite stones caused by infection, a special diet low in magnesium and phosphorus, along with appropriate antibiotics, can help dissolve the stones over time. This process might take longer for kidney stones compared to those located in the lower urinary tract.
- Medication: In some cases, medications may be prescribed to help dissolve certain types of stones, such as urate stones, or to manage associated symptoms like pain or infection. It's important to note that calcium oxalate stones, the most common type in cats, cannot be dissolved with medication.
2. Surgical intervention
For large stones, those causing obstruction, or those not responding to medical management, surgical removal may be the most effective option. Various surgical techniques are available, and the choice depends on the specific case.
3. Observation
If the stones are small, do not cause any problems, and your cat is otherwise healthy, we may recommend regular monitoring through periodic examinations and imaging to track any changes in their size or number.
What is the prognosis for cats with kidney stones?
Some cats with kidney stones can live comfortable lives for years, especially if the stones are small, not causing any problems, and are regularly monitored by your veterinarian.
With that, kidney stones in cats can cause ongoing kidney pain, blood in urine, frequent urinary infections, and blockages in the urinary tract.
The ultimate prognosis depends on whether there are other health issues, like chronic kidney disease or kidney infections, and how serious those issues are.
If you have any further questions or are concerned that your cat may have kidney stones, please contact your veterinarian.