Assessment of cross-linked polydimethylsiloxane urethral bulking agent in young dogs with urethral sphincter mechanism incompetence

Authors: Reynolds RM, Bordicchia M, Graham KJ
Publication: Australian Veterinary Practitioner, Volume 54, Issue 3, pp 141-156, Sep 2024
Publisher: Australian Veterinary Association

Article class: Clinical Article

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Abstract:

Objective: To evaluate the safety and efficacy of cross-linked polydimethylsiloxane (CPDS) for urethral bulking in young dogs with naturally occurring urethral sphincter mechanism incompetence (USMI).

Methods: Retrospective study evaluating dogs diagnosed with USMI that received CPDS between June 2020 and December 2022. Prior treatment with oral incontinence medications or alternative urethral bulking agents (UBA) was allowed. Animals with other causes of incontinence were excluded. Response was assessed via clinical signs and incontinence scoring pre- and post-procedure, using both veterinary evaluation and client questionnaires retrospectively. Safety evaluation included identification and grading of adverse reactions.

Results: Seven dogs were included: six females, one male. Continence was achieved in all cases immediately post-procedure. Four of seven were continent 6 months post procedure, one at 12 months. The median duration of action was 9 months (range 7 days to 18 months). Median incontinence scores improved from 4 to 2 post-procedure. Five dogs had adverse reactions within 25-45 minutes of CPDS implantation, one developed anaphylaxis. Cases were medically managed and recovered fully, without ongoing concern.

Conclusions: CPDS is minimally invasive and results in resolution of incontinence immediately post-procedure, but length of continence ranged from 7 days to 18 months, with a median duration of 9 months. Furthermore, its safety profile is concerning.

Clinical Relevance: CPDS can be considered cautiously as a first line UBA when no alternative treatment is available. In young dogs, it could be used as a bridging treatment for medically non-responsive incontinence in immature female dogs to allow them to reach adolescence when desexing and corrective procedures are considered.

KEYWORDS: Urethral, sphincter, polydimethylsiloxane, bulking, dogs.

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