Case report highlights urethral stenting in dog with complex obstruction: full analysis

A case report in Veterinary Sciences highlights a difficult but familiar emergency for small animal clinicians: a dog with lower urinary tract obstruction that wasn't caused by just one disease process. The patient, a 14-year-old spayed female Maltese, had hematuria, pollakiuria, decreased urine volume per void, and prolonged urination, with workup pointing to both a trigonal mass suspicious for transitional cell carcinoma and severe, diffuse urolithiasis affecting the kidneys, ureters, bladder, and urethra. The authors describe urethral stenting as a palliative intervention to restore patency in the face of multifactorial obstruction. (sciencedirect.com)

That combination matters because canine transitional cell carcinoma, now more commonly termed urothelial carcinoma in much of the literature, has a strong tendency to arise in the trigone and extend into the urethra. Reviews have found that urethral involvement occurs in more than half of dogs with the disease, and that local progression, not just metastasis, can become the immediate clinical problem when urine outflow is compromised. At the same time, urinary stones can independently obstruct the outflow tract, worsen inflammation, and complicate interpretation of imaging and urine-based diagnostics. (sciencedirect.com)

The case report's value is in showing how those problems can stack. According to the abstract, the dog's diagnosis was based on serum biochemical analysis, radiography, and ultrasonography, which together showed diffuse urolithiasis, urethral involvement, and a trigonal mass consistent with neoplasia. In dogs with suspected urothelial carcinoma, that pattern creates a management dilemma: surgery is often limited by tumor location, especially in the trigone, while obstruction still has to be relieved quickly to preserve renal function, reduce discomfort, and allow further treatment planning. Reviews of malignant urinary tract obstruction in companion animals describe urethral stenting as a minimally invasive way to re-establish flow when definitive resection isn't realistic. (sciencedirect.com)

The broader literature supports the rationale, while also underscoring the limits. A review of malignant urinary tract stenting in dogs reported technical and clinical success rates above 94% for canine urethral stenting in published malignancy series. But success at placement doesn't eliminate downstream complications. Other reports and reviews describe urinary incontinence, recurrent obstruction from tumor progression, urinary tract infection, pain, and stent migration as persistent concerns. In one review aimed at clinicians, median survival after stent placement was reported in the range of roughly 32 to 78 days in some historical series, although outcomes vary with tumor burden, adjunctive therapy, and case selection. (mdpi.com)

Industry and expert commentary around canine transitional cell carcinoma has also emphasized how easily these cases can be mistaken for chronic or recurrent urinary tract disease early on. In a 2024 dvm360 interview, oncologist Craig A. Clifford said the disease often presents with signs that resemble urinary tract infection, contributing to delayed recognition. That context is relevant here because a dog with stones, lower urinary tract signs, and a suspected trigonal mass may require clinicians to think beyond a single-cause explanation and prepare pet parents for a palliative, multimodal pathway rather than a curative one. (dvm360.com)

Why it matters: For veterinary teams, this report is less about proving a new standard of care and more about sharpening clinical judgment. Dogs with concurrent neoplasia and severe urolithiasis may not fit neatly into medical oncology, surgery, or interventional radiology alone. The practical question is often which intervention will restore urine flow fastest, with the least morbidity, and with a realistic quality-of-life benefit. In that setting, urethral stenting can be a useful bridge or palliative endpoint, but clinicians still need to counsel pet parents about incontinence risk, infection surveillance, possible re-obstruction, and the likelihood that local control of disease remains incomplete. (mdpi.com)

The case also reinforces the importance of thorough imaging and staging. Because trigonal urothelial carcinoma can involve the urethra and, in some dogs, contribute to upper tract changes through obstruction, identifying the full burden of disease changes both prognosis and procedure planning. Severe cystolithiasis adds another layer, potentially worsening obstruction mechanically while also complicating urine sampling, interpretation of hematuria, and discussions about whether signs are stone-driven, tumor-driven, or both. (sciencedirect.com)

What to watch: The next step for the field is better evidence on case selection. More retrospective data comparing stenting, cystostomy-based diversion, endoscopic debulking, and multimodal oncology treatment in dogs with mixed obstructive disease could help define when stenting offers the best balance of speed, palliation, and quality of life, especially in older patients with concurrent upper and lower urinary tract involvement. (mdpi.com)