Calcium Phosphate Urolithiasis in Dogs
Urolithiasis refers to the formation of stones (uroliths) in the urinary tract of dogs. These stones come in various types, with calcium phosphate stones being one of them. Also recognized as apatite uroliths, calcium phosphate stones are predominantly found in the kidneys rather than the urinary bladder.
Symptoms
The symptoms can differ based on the location, size, and quantity of stones present in the urinary tract. In certain cases, dogs may not exhibit any apparent signs of the condition, and its detection may only occur later during a routine examination, if at all. The following are common symptoms linked with calcium phosphate urolithiasis:
- Increased urination (polyuria)
- Difficulty urinating (such as dribbling of urine)
- Pain during urination
- Presence of blood in the urine
Causes
The causes include:
- Overconsumption of calcium in the diet
- Excessive usage of mineral supplements (for instance, vitamin D)
- Different kidney diseases or infections
Diagnosis
Following a comprehensive medical history assessment of your pet, your veterinarian will conduct a physical examination, including a blood chemical profile, complete blood count, urinalysis, and electrolyte panel for the dog. While these tests’ results may appear normal in some cases, exceptions exist. Elevated levels of calcium in the blood may be detected in certain dogs through the biochemistry profile. Dogs experiencing severe kidney damage or urinary tract blockage may exhibit elevated levels of waste products like urea in their blood.
Biochemical alterations linked to underlying diseases aid in diagnosing the root cause. Additionally, microscopic analysis of urine proves valuable in determining the stone’s type.
Treatment
Since there are no effective medications available for this type of stone, the primary treatment approach involves dissolving the stone. Surgery may become necessary to eliminate stones from the urinary tract, particularly in cases where alternative methods are impractical.
In instances where the stones cause urethral obstruction, they can sometimes be maneuvered back into the bladder. A technique known as urohydropropulsion is commonly employed for this purpose, utilizing a specialized urinary catheter inserted into the urethra to push the stone back into the bladder.
A newer technique called extracorporeal shock wave lithotripsy is also available, offering a minimally invasive option. This method employs shockwaves focused on the stone, causing it to fragment and subsequently pass through urine.
Following stone removal through either technique, your veterinarian will utilize appropriate radiographic methods to confirm complete elimination of stones. Abdominal x-rays or ultrasound examinations are typically conducted at three to five month intervals to facilitate early detection of stone formation and prevent the need for repeat surgery.
It is crucial to address the underlying cause of stone formation effectively to prevent future episodes from occurring.
Living and Management
Your veterinarian will usually recommend a new diet regimen for your dog to help prevent future episodes. It’s important not to make significant changes to your dog’s diet without consulting your veterinarian beforehand.