Kidney stones in dogs: detection, treatment and prevention

Kidney stones can cause significant discomfort for dogs. But how do you recognize this disease early and what treatment methods are available?

What are kidney stones in dogs?

Kidney stones, also known technically as nephrolithiasis, are solid deposits that form from excess minerals in the dog's urine. These crystalline accumulations can vary in size and shape and form when mineral salts are present in excessive concentrations in the kidney.

Types of kidney stones in dogs and their formation

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Kidney stones in dogs are solid deposits that can form in the kidneys and have different chemical compositions. The formation of these stones depends on various factors, including diet, water balance and genetic predispositions. The following describes the most common types of kidney stones in dogs and how they form.

1. Struvite stones

• Description: Struvite stones consist mainly of magnesium, ammonium and phosphate. They are often associated with bacterial urinary tract infections.
• Formation: They often form in alkaline urine and can be promoted by urinary tract infections with certain bacteria that break down urea. A diet high in protein can also contribute to the formation of these stones.

2. Calcium oxalate stones

• Description: These stones are made of calcium salts and oxalic acid.
• Formation: They tend to form in acidic urine. Some factors that may contribute to their formation include excessive calcium intake, high dietary oxalic acid intake, and certain medications. Genetic factors can also play a role.

3. Urate stones

• Description: Urate stones are often found in breeds such as Dalmatians and English Bulldogs.
• Origin: They arise from an abnormality in uric acid metabolism. This leads to excessive excretion of uric acid in the urine. A low urine pH also promotes their formation.

4. cystine stone

• Description: Cystine stones are formed by the deposition of the amino acid building block cystine.
• Development: They arise when there is a genetic defect that impairs the reabsorption of cystine in the kidneys. This leads to an increased concentration of cystine in the urine.

5. Silicate bricks

• Description: These rather rare stones are made of silicone, an element found in the earth.
• Origin: The exact cause is not completely clear. However, it is believed that high dietary silicate intake, such as in certain plants or soils, may contribute to the formation of these stones.

Symptoms of Kidney Stones in Dogs

Detecting kidney stones in dogs can be done early by observing specific symptoms. These symptoms can vary from mild to severe and are often an indicator of the presence of stones or other urinary tract problems. As a responsible dog owner, it is crucial to recognize these signs early and act promptly.

1. Changed urge to urinate

A common sign of kidney stones is a sudden change in the dog's urination behavior. This can mean:

• Urinating more frequently than usual
• Difficulty or hesitation in urinating
• Small amounts of urine despite visible exertion

2. Blood in urine

Another serious symptom is the presence of blood in the urine, which can manifest as a pink or red color to the urine.

3. Pain and discomfort

Dogs with kidney stones may show signs of pain such as:

• Whining or whining when urinating
• Increased irritability or aggressiveness
• A hunched back or trembling, especially when trying to urinate

4. lethargy

A dog suffering from kidney stones may become lethargic, lose interest in activities, or sleep more than usual.

5. Loss of appetite

Another symptom can be a sudden aversion to food or even a complete loss of appetite. In some cases, vomiting or diarrhea may also occur.

6. stomach pain

Some dogs with kidney stones show signs of abdominal pain, such as sensitivity to touch or constant licking of the genital area.

Diagnosis of kidney stones in dogs

Accurately diagnosing kidney stones in dogs is crucial to proper treatment and the animal's well-being. A competent veterinarian will use various diagnostic methods to determine the presence, type and size of the stones. Here are the most common diagnostic approaches.

1. Clinical examination

First, the veterinarian will conduct a complete clinical examination to assess the dog's general health and identify early signs of kidney stones or urinary tract problems.

2. Urinalysis

A urine test provides important information about the health of the kidneys and urinary tract. The vet will look for signs of blood, elevated mineral levels, and other abnormalities that could indicate kidney stones.

3. Blood tests

A blood count provides information about kidney function and shows whether there is an infection or other abnormalities. Certain blood counts may be elevated if the kidneys are impaired.

4. X-ray examination

Many kidney stones are visible on x-rays. This imaging method allows the veterinarian to determine the size, shape and location of the stones within the kidney or urinary tract.

5. Ultrasonic

An ultrasound is particularly helpful in identifying stones that may not be visible on an x-ray. This method provides a detailed picture of the kidneys and urinary tract and can also be used to assess blood flow in the kidneys.

6. Urethrogram

During this special x-ray examination, a contrast agent is injected into the urinary tract to make the contours of the urethra more visible. This can help identify stones or strictures along the urinary tract.

Breeds with increased susceptibility to kidney stones in dogs

While any dog ​​can develop kidney stones regardless of breed, there are certain breeds that are genetically more susceptible to this condition. A deeper understanding of genetic predisposition can help dog owners identify potential health risks early and take preventative measures.

1. Dalmatian

• Special feature: The formation of urate stones is particularly common in Dalmatians. Around 75-96% of all cases of urinary stones in this breed consist of urate stones. This is due to a genetic defect that leads to increased excretion of uric acid in the urine.

2. English bulldogs

• Special feature: English bulldogs are also prone to the formation of urate stones, often as a result of certain metabolic disorders.

3. Shih Tzu

• Special feature: This breed has an increased tendency to form calcium oxalate stones, especially in older males.

4. Lhasa Apso

• Special feature: Similar to the Shih Tzu, the Lhasa Apso tends to form calcium oxalate stones.

5. Miniature Schnauzer

• Special feature: Miniature Schnauzers have a genetic predisposition to calcium oxalate stones. Monitoring their diet and the pH of their urine is therefore particularly important.

6. Bichon Frize

• Special feature: Struvite and calcium oxalate stones may occur more frequently in this breed, which may be due to genetic and dietary factors.

7. Yorkshire Terriers

• Special: Yorkshire Terriers are also prone to calcium oxalate stones, especially when exposed to a high-protein diet.

8. Newfoundland

• Special feature: Newfoundlands may have a genetic predisposition to the formation of cystine stones.

Dietary recommendations for dogs with increased susceptibility to canine kidney stones

Proper nutrition plays a crucial role in preventing and treating kidney stones in dogs. A specially tailored diet can help reduce the risk of stone formation and dissolve existing stones or inhibit their growth.

1. Increase fluid intake

• Why? Increased fluid intake dilutes urine and reduces the concentration of stone-forming minerals.
• How? Make sure fresh water is always available. Wet food can also help increase overall fluid intake.

2. Controlled protein consumption

• Why? Excess protein can lead to increased excretion of calcium, oxalate and uric acid, which promotes stone formation.
• How? Choose a moderate protein diet food specifically designed for dogs with kidney problems.

3. Calcium and phosphorus in balance

• Why? An imbalance of these minerals can promote the formation of calcium oxalate stones.
• How? Avoid foods high in calcium or phosphorus. Opt for special diet food that contains these minerals in balanced amounts.

4. Reduced intake of oxalate-rich foods

• Why? Foods high in oxalate can promote the formation of calcium oxalate stones.
• How? Avoid feeding spinach, beets, sweet potatoes, and nuts.

5. Regulate urine pH

• Why? The pH of urine influences stone formation. Urine that is too acidic or too alkaline can increase the risk of certain types of stones.
• How? Some diet foods are formulated to maintain urine pH within an optimal range. It is also possible to check urine pH regularly and adjust the diet accordingly.

6. Sodium-restricted diet

• Why? Excess sodium can increase calcium levels in the urine.
• How? Choose a diet food with reduced sodium content.

7. Omega-3 fatty acids

• Why? Omega-3 fatty acids may have anti-inflammatory properties and support kidney health.
• How? Incorporate oils such as fish oil or flaxseed oil into your diet or choose diet foods that contain these fatty acids.

Treatment options for kidney stones in dogs

Treatment for kidney stones in dogs depends on the type, size and location of the stone, as well as the animal's general condition. The most common treatment strategies are explained in detail here:

1. Medicinal dissolution

• Description: Some kidney stones can be dissolved with special medications. This is particularly possible with struvite stones.
• Procedure: The vet prescribes medication that breaks down the minerals contained in the stone. In parallel, a special diet is often recommended to support dissolution.

2. Diet change

• Description: Feeding specially formulated diet foods may help dissolve certain types of stones and prevent them from forming again.
• Procedure: Based on a urinalysis and the type of stone, a special diet is recommended that regulates the urine pH and minimizes the excretion of stone-forming substances.

3. Urohydropropulsion

• Description: This is a non-surgical procedure that flushes stones from the bladder.
• Procedure: The dog is sedated and a catheter is used to introduce sterile fluid into the bladder and then quickly suction it out, removing smaller stones from the bladder.

4. Lithotripsy

• Description: A process in which stones are broken using sound waves.
• Procedure: Ultrasonic waves are aimed specifically at the stone in order to break it into smaller fragments, which can then be naturally excreted.

5. Surgical removal

• Description: For larger stones or when other methods are not effective, surgery may be necessary.
• Procedure: Under general anesthesia, surgical access to the bladder or renal pelvis is created to remove the stone directly.

6. Antibiotics

• Description: Urinary tract infections may contribute to stone formation. Therefore, administration of antibiotics may be necessary.
• Procedure: A urine culture test is carried out to identify the exact type of pathogen and based on this, an appropriate antibiotic is prescribed.

7. Pain management

• Description: Stones can cause pain and discomfort.
• Procedure: Painkillers, such as NSAIDs or other analgesics, can be administered to relieve pain and improve the dog's general condition.

Frequently asked questions (FAQs) about kidney stones in dogs

Summary Kidney stones in dogs

Kidney stones in dogs are a health problem caused by an overconcentration of minerals in the urine. These deposits can lead to pain, urinary tract infections, and other complications. Dog owners often don't immediately recognize the signs of kidney stones in dogs. Therefore, it is essential to pay attention to symptoms such as blood in the urine, frequent urination or pain when urinating.

The formation of kidney stones in dogs can be influenced by several factors, including the animal's diet, genetic predisposition, or repeated urinary tract infections. Certain breeds, such as Dalmatians or English bulldogs, are more susceptible to kidney stones, which is why understanding breed-specific risks is important.

Diagnosing kidney stones in dogs usually requires a thorough examination by a veterinarian, who can use x-rays or ultrasounds to locate the stones. There are different types of kidney stones in dogs, each requiring different treatment approaches.

Treatment for kidney stones in dogs can range from dietary changes to drug therapies to surgery, depending on the type and size of the stone. It is essential that dog owners educate themselves about the various treatment options for kidney stones in dogs and work closely with their veterinarian.

An important aspect of managing kidney stones in dogs is prevention. A balanced diet, encouraging adequate fluid intake, and regular veterinary check-ups can help reduce the risk of stone formation.

In summary, understanding kidney stones in dogs is of great importance for every dog ​​owner. Through attention, prevention and appropriate care, kidney stones in dogs can be effectively treated and, in many cases, prevented. It remains of central importance to always put the animal's well-being first and to act quickly if there are signs of kidney stones in dogs.

Literature on the subject of kidney stones in dogs

The literature on the topic of “kidney stones in dogs” includes a variety of textbooks, journal articles, and studies published by veterinarians, veterinary physicians, and professionals in the field. Here are some recommended literature sources in German:

1. Clinical Laboratory Diagnostics in Veterinary Medicine by Jürgen Zentek, Helmut Aupperle, and Thomas Göbel - This comprehensive handbook provides deep insights into diagnostics, including the examination of kidney stones in dogs.
2. Kidney Diseases in Dogs by Ulrich Truyen, Peter F. Suter, and Hans Lutz - A specific book that addresses kidney disease in dogs and provides valuable information about kidney stones.
3. Dietetics and Clinical Nutrition of Dogs and Cats by Ellen Kienzle and Richard D. Alldinger - A work that focuses on the dietary treatment and prevention of kidney stones in dogs.
4. The Dog in Clinic and Practice by Klaus Failing and André Jaggy – This book covers a wide range of health problems in dogs, including kidney stones.
5. Urological diseases in dogs and cats by Peter F. Suter and Reto Neiger - A deep insight into urological problems in pets, where kidney stones are discussed in detail.
6. Veterinary medical journals such as "Veterinary Practice", "Deutsche Veterinary Weekly" or "Journal for Small Animal Practice" regularly publish articles and studies on the subject of kidney stones in dogs.

For a more in-depth discussion of the topic, we recommend using these literature sources and, if necessary, obtaining additional literature from libraries or specialist bookstores. It is also advisable to consult current studies and articles from veterinary databases to stay up to date with the latest research.