20 May Bladder Stones in Dogs
Urolithiasis in dogs
There are many types of bladder stones and each tends to form in a specific breed or species under specific conditions.
Facts:
- 85% of patients with struvite bladder stones are female
- Breeds felt to have an increased risk for the formation of struvite stones are the Miniature Schnauzer, Shih Tzu, Yorkshire terrier, Labrador retriever and Dachshund.
- The most common bladder stones (uroliths) are struvites and calcium oxalate.
Risk factors:
- Diet
- Bacterial infections/urinary tract infections
- Abnormal urine pH
- Acidic urine pH increases the risk for calcium oxalate stone development
- An alkaline urine pH will increase the risk of struvite stone formation.
- Rarer causes for struvite stones include certain antacids, diuretics, Hyperaldosteronism
When to suspect your dog has stones:
- Bloody urine
- Recurrent bladder infections
- Difficulty/straining to urinate
How we diagnose that your dog has bladder stones:
- Clinical signs
- Urinalysis
- Imaging – radiographs/ultrasounds
What can be done:
- Dietary dissolution – there are prescription diets designed to dissolve and then prevent urinary stones – these will be recommended at your vet’s discretion.
- Surgical removal – this is the fastest and most direct method however every surgery has risks associated with anaesthetics, post-operative pain, risk of abdominal contamination etc and your veterinarian should discuss all the pros and cons with you.
- Voiding Urohydropulsion – if stones are small enough, they have the potential to be manipulated and passed from the bladder to urethra using high pressure.
- Specialist procedures – cystoscopic retrieval/laser lithotripsy.
Long term:
- Most cases require long term management and regular check-ups, especially for those cases that may be predisposed to bladder infections.
- A well-balanced nutritional diet is very important to ensure the urine pH is maintained at neutral.
Case Study:
Our star patient of the month is an 11-year-old Maltese cross desexed female. She initially presented for excessive urination and blood in her urine. She was treated medically for a urinary tract infection, but DR Storm was concerned about the presence of bladder stones as she really disliked her abdomen being touched. The patient urinalysis indicated that bacteria and red blood cells were present, he pH was 8 which is quite alkaline and there was no evidence of crystals. She went home with antibiotics, anti-inflammatories and instructions to come back if her clinical signs hadn’t stopped within 48 hours.
The patient returned about four days later, still a very happy little dog, but she had started urinating blood again.
She was sedated and had radiographs performed. Once sedated, and thus pain free, we were able to palpate her bladder full of stones (imagine a bag of marbles). Her x-rays indicated a bladder full of radio-opaque (white) stones.
She was taken to surgery and a cystotomy was performed to remove the stones and flush out her bladder and urethra to remove the tiny “sand” and smaller stones.
She recovered well and went home on a prescription diet that is formulated to encourage a neutral urine pH (around 7) and a healthy bladder. She has since returned and has recovered beautifully; she is urinating regularly and without difficult and there is no more blood in her urine.