Home » Diseases » In cats » Urolithiasis (Urinary Tract Stones, Stones and Crystals in the Renal Pelvis, Ureter, Bladder and/or Urethra, as Well as in the Urine)

Urolithiasis (Urinary Tract Stones, Stones and Crystals in the Renal Pelvis, Ureter, Bladder and/or Urethra, as Well as in the Urine) in cats

Occurrence: common
Location of illness: Abdomen/pelvis

Urolithiasis in cats describes the formation and accumulation of stones or crystals in the urinary tract, including the renal pelvis, ureter, bladder, and urethra. These stones can obstruct urine flow and lead to various health problems.

The most important facts at a glance

Urolithiasis in cats is a condition in which urinary stones form in the urinary tract. This happens when the urine is supersaturated with minerals that form crystals and eventually stones. The most common types of stones include struvite and calcium oxalate stones, which form depending on urine pH and other factors. Insufficient water intake, genetic predisposition, and an unbalanced diet can promote stone formation. Symptoms include frequent urinary urgency, difficult or painful urination, and blood in the urine. Diagnosis is made through clinical examinations, urinalysis, and imaging procedures such as X-rays and ultrasound. Treatment depends on the type and size of the stones and may include special diets, medications, or surgical procedures. Preventive measures include adequate water intake, adapted nutrition, and regular veterinary check-ups. Research focuses on genetic predispositions, nutritional factors, and new diagnostic and therapeutic approaches. Good education of pet owners can help reduce the risk of the disease.

Causes

The formation of urinary stones is a complex process caused by supersaturation of minerals in the urine. These minerals can form crystals that combine to form stones. Various factors, such as urine pH and urine concentration, influence crystal formation.

There are different types of urinary stones; the most common in cats are struvite and calcium oxalate stones. Struvite stones consist of magnesium, ammonium, and phosphate and often form in alkaline urine. Calcium oxalate stones, on the other hand, develop in acidic urine and are more common in older cats.

Causes of urinary stone formation are diverse. Insufficient water intake can lead to concentrated urine, which promotes stone formation. Genetic factors also play a role, as some cat breeds are more susceptible to certain types of stones. Nutrition is another significant factor; diets high in magnesium and phosphorus can promote the formation of struvite stones.

Urinary tract infections can also contribute to stone formation, as they alter the pH of the urine and promote the growth of bacteria that can produce struvite crystals. Certain medications and conditions, such as hypercalcemia, also increase the risk of urinary stones.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

The symptoms of urolithiasis in cats vary depending on the location and size of the stones. A common sign is frequent urination in small amounts, often accompanied by pain. Cats may also urinate outside the litter box, which may indicate discomfort.

Blood in the urine, also known as hematuria, is another symptom that may indicate the presence of urinary stones. Cats may also show signs of lethargy and loss of appetite, especially if the stones are causing pain or an infection is present.

A complete urinary tract obstruction is an emergency that requires immediate veterinary attention. Symptoms include severe pain, frequent but unsuccessful urination, and in severe cases, vomiting and collapse.

Diagnosis

The diagnosis of urolithiasis usually begins with a thorough clinical examination and a review of the medical history. The veterinarian will often perform a urinalysis to identify crystals, blood, and bacteria in the urine. The pH of the urine can also be measured to provide clues about the type of stones.

Imaging procedures such as X-rays and ultrasound are crucial for diagnosis, as they can show the location and size of the stones. X-rays are particularly useful for detecting calcium oxalate stones, while ultrasound can help identify stones that are not visible on X-rays.

In some cases, a urine culture may be necessary to identify bacterial infections that may be contributing to stone formation. Further blood tests may be necessary if metabolic disorders are suspected.

Therapy

The treatment of urolithiasis depends on the type, location, and size of the stones. Smaller struvite stones can often be dissolved with a special diet that lowers the pH of the urine and promotes stone dissolution. However, these diets are not effective for calcium oxalate stones.

Medications can be used to relieve pain and treat infections. A catheter may be required to restore urine flow and empty the bladder in the event of a complete urinary tract obstruction.

In severe cases where the stones do not respond to diet or medication, surgery may be necessary to remove the stones. These operations are generally successful but carry the risk of complications.

Prognosis and follow-up care

The prognosis for cats with urolithiasis varies depending on the type and severity of the condition. With early diagnosis and treatment, the prognosis is generally good, especially for struvite stones that respond to dietary measures.

Calcium oxalate stones are more difficult to treat because they do not respond to dietary measures. Cats with these stones may require repeated surgical procedures, which complicates the prognosis.

If left untreated, urolithiasis can lead to serious complications, including kidney damage and infections, which can significantly shorten the cat’s life expectancy. Continuous monitoring and follow-up care are crucial for successful treatment.

Prevention

To minimize the risk of urolithiasis in cats, owners should ensure that their cats drink enough water. One way to encourage this is to provide fresh water in several places in the house, as well as to use drinking fountains, which often encourage cats to drink. A diet specifically designed to prevent the formation of stones can also be helpful. Such diets are often available from veterinarians and contain special ingredients that support urinary tract health.

Regular veterinary check-ups are important to detect potential problems early. These check-ups allow the veterinarian to examine the urine for crystals or an altered composition, which could indicate an increased risk of stone formation. In addition, stress factors in the cat’s environment should be reduced, as stress can negatively affect urinary tract health. A clean and stress-free environment in which the cat can eat and drink undisturbed contributes to general health.

It is also advisable to keep an eye on the cat’s weight, as overweight can increase the risk of urinary tract problems. A balanced diet combined with sufficient exercise helps to control weight and promote general health.

Outlook on current research

Research on urolithiasis in cats is currently focused on several key areas to improve the understanding, prevention, and treatment of this condition. One of the main goals of research is to identify the genetic predispositions that make cats more susceptible to the formation of urinary stones. Scientists are investigating genetic markers associated with an increased susceptibility to certain types of stones, such as struvite or calcium oxalate stones. These findings could lead to the development of genetic tests in the future that help veterinarians identify at-risk cats early on.

Another important area of research concerns the nutritional factors that can contribute to the formation of urinary stones. Researchers are analyzing how different compositions of cat food – especially the content of magnesium, calcium, phosphate, and other minerals – affect the risk of stone formation. The role of urine pH and water intake of cats is also being investigated. These studies aim to develop specially formulated diets that minimize the risk of urolithiasis.

Innovations in imaging diagnostics also play a significant role in current research. Advances in ultrasound and X-ray technology allow urinary stones in cats to be detected more accurately and earlier. Researchers are working to improve the accuracy and accessibility of these technologies to increase diagnosis rates and reduce unnecessary invasive procedures.

The development of new therapeutic approaches is another focus of research. Scientists are investigating various drugs that could help dissolve existing stones or prevent their formation. The efficacy and safety of such drugs are being tested in clinical trials, with an emphasis on minimizing side effects. In parallel, minimally invasive procedures are being developed to remove urinary stones without the need for extensive surgery.

Finally, research is also being conducted on how pet owners can be better informed about the prevention of urolithiasis. Studies on behavioral change and improving communication between veterinarians and pet owners aim to increase compliance with diet and water intake recommendations. Research shows that better education of pet owners can lead to a significant reduction in disease rates.

Frequently asked questions (FAQs)

What is urolithiasis in cats? Urolithiasis is a condition in which solid deposits, called urinary stones or crystals, form in a cat’s urinary tract. These stones can occur in the kidney, ureter, bladder, or urethra and cause pain, infections, or blockages.
What symptoms occur in cats with urolithiasis? Common symptoms include difficulty or pain when urinating, frequent urination of small amounts, blood in the urine, and in severe cases, complete urinary retention. Affected cats may also appear lethargic or show a loss of appetite.
What causes urinary stones in cats? The exact cause can vary, but factors such as genetic predisposition, diet, water consumption, and urine pH play a role. An imbalance of certain minerals in the food can also contribute to stone formation.
How is urolithiasis diagnosed? Diagnosis is usually made through a combination of clinical symptoms, urinalysis, and imaging procedures such as X-rays or ultrasound to locate the stones and assess their size.
Can urinary stones in cats be treated without surgery? In some cases, special diets or medications can help dissolve certain types of stones. However, surgery may be required to remove other types of stones or larger stones.
What role does nutrition play in the prevention of urolithiasis? A balanced diet with controlled amounts of minerals and an appropriate pH can significantly reduce the risk of stone formation. It is important to coordinate the diet with the veterinarian to consider the specific needs of the cat.
How important is water intake in cats? Adequate water intake is crucial to increase urine production and dilute the concentration of minerals in the urine, which reduces the risk of stone formation. Many veterinarians recommend feeding wet food or providing additional water sources.
Are there certain cat breeds that are more susceptible to urolithiasis? Yes, some breeds such as Persian cats and Himalayan cats appear to be genetically predisposed. Nevertheless, urolithiasis can occur in any cat, regardless of breed.
Is urolithiasis in cats a serious condition? Yes, if left untreated, urolithiasis can lead to serious complications such as kidney failure or a life-threatening blockage of the urinary tract. Early diagnosis and treatment are crucial to avoid serious health problems.
How can I minimize the risk of urinary stones in my cat? Regular veterinary check-ups, a balanced diet, good water intake, and observation for early symptoms can reduce the risk. Special diets should be considered for cats with a history of urinary stones or a genetic predisposition.