A Case of Canine Urolithiasis: Treatment and Reflections

Canine urolithiasis, a common urinary tract disease in small animals, is characterized by the supersaturation of inorganic or organic salts in urine, leading to crystal formation and subsequent stone formation. The incidence of this condition is increasing, likely due to improved living standards and advancements in veterinary care. This case report details the diagnosis, treatment, and post-operative management of a single case, along with a broader discussion of the disease’s etiology, diagnosis, and treatment strategies.

Case Presentation:

A nine-year-old male Pekingese presented with clinical signs indicative of urolithiasis. The dog exhibited restlessness, decreased appetite, and a progressively enlarging abdominal girth. The patient strained frequently to urinate, producing only small amounts of bloody urine. Palpation revealed a tense abdominal wall and a distended bladder.

Diagnosis:

Based on the clinical presentation, a preliminary diagnosis of bladder urolithiasis was made. To confirm this, a diagnostic procedure was performed. A lubricated, blunt-ended catheter was gently inserted into the urethra. Resistance was encountered, confirming the presence of a urethral obstruction likely caused by stones. This was further corroborated by manual palpation, which revealed a palpable mass consistent with uroliths. Radiographic imaging subsequently confirmed the presence of a large (approximately the size of a hen’s egg) bladder stone.

Surgical Intervention:

A right paramedian abdominal incision was made, exposing the abdominal cavity. The bladder was carefully exteriorized, isolated with sterile gauze, and a double-traction suture placed on the proposed incision site. A small incision was made, which was then extended using surgical scissors to create a full-thickness cystotomy. The large stone was visualized and removed using forceps and a sterile curette. The bladder and urethra were thoroughly irrigated with warm sterile saline solution to ensure complete removal of the stone fragments and blood clots. A small amount of ampicillin was instilled into the bladder.

The bladder was then closed in two layers: a continuous full-thickness suture for the first layer, followed by a continuous inverting Lembert suture for the second layer to ensure water-tight closure and prevent leakage. The abdominal cavity was closed routinely, and the skin was closed with interrupted sutures. Post-operative analgesia and prophylactic antibiotics (e.g., cefoxitin sodium, amikacin, and metronidazole) were administered to mitigate pain and prevent infection. A urinary catheter was left in place for several days to monitor urine output and prevent infection. The retrieved stone was meticulously examined for composition, which is crucial in tailoring appropriate preventive strategies for future recurrence.

Post-operative Care and Outcome:

Post-operative management included strict monitoring of the patient for signs of infection, pain, or urinary obstruction. The patient was kept in a quiet, comfortable environment, and an Elizabethan collar was used to prevent self-trauma. Intravenous fluid therapy was administered for hydration, and antibiotics were continued for five days. The patient recovered well; the sutures were removed after one week, and normal urination was restored within fifteen days. The patient was discharged in good health.

Etiology and Risk Factors:

The formation of urinary stones is a complex process involving multiple contributing factors. Breed predisposition plays a role, with certain breeds such as Pekingese, Yorkshire Terriers, and Bulldogs exhibiting a higher incidence. Sex also seems to be a factor, with male dogs having a greater risk, potentially due to a longer urethra. Age is also relevant, with older dogs more susceptible, potentially due to hormonal imbalances or decreased activity levels leading to urinary stasis.

Dietary factors are significant. High-protein diets, particularly those rich in animal viscera (liver, kidney), can increase the risk of stone formation. Inadequate water intake leads to concentrated urine, promoting salt crystallization. Underlying conditions such as chronic hypercalcemia, hyperparathyroidism, and vitamin D toxicosis can disrupt calcium metabolism, increasing the risk of calcium oxalate stone formation. Finally, urinary tract infections (UTIs) caused by urease-producing bacteria (e.g., Proteus spp., Staphylococcus spp.) can elevate urine pH, favoring struvite stone formation. In this case, the post-operative antibiotic regime targeted such bacterial infections, mitigating this risk.

Prevention and Long-Term Management:

Preventing recurrence is crucial in managing urolithiasis. Dietary management is key, focusing on providing a balanced diet, appropriate protein levels, and controlled mineral intake (particularly phosphorus and calcium). Increasing water intake is essential to dilute urine and reduce salt concentration. Regular veterinary check-ups, including urinalysis and blood work, are recommended to monitor renal function and detect early signs of recurrence. Owners must strictly adhere to prescribed medication regimens, avoiding unauthorized changes or discontinuation of therapy. Further analysis of the retrieved stone is crucial to guide specific dietary recommendations and prevent future occurrences. This may involve further laboratory testing (e.g., specific gravity, pH, crystal identification), potentially influencing future prophylactic recommendations.

Conclusion:

This case illustrates the successful management of canine urolithiasis through surgical intervention and meticulous post-operative care. Understanding the multifaceted etiology of this condition highlights the importance of a holistic approach to diagnosis, treatment, and long-term management. Close collaboration between the veterinarian and owner is paramount to minimizing recurrence and ensuring the long-term health and well-being of the affected dog. Further research into the specific factors contributing to stone formation in individual patients is necessary to optimize preventive strategies and improve patient outcomes.