Urethral sphincter mechanism incompetence in the male dog: importance of bladder neck position, proximal urethral length and castration

Authors

  • S. C. Power,

    Corresponding author
    1. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS18 7DU
      *Please address all correspondence to P. E. Holt
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  • K. E. Eggleton,

    Corresponding author
    1. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS18 7DU
      *Please address all correspondence to P. E. Holt
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  • A. J. Aaron,

    Corresponding author
    1. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS18 7DU
      *Please address all correspondence to P. E. Holt
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  • P. E. Holt,

    Corresponding author
    1. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS18 7DU
      *Please address all correspondence to P. E. Holt
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  • P. J. Cripps

    Corresponding author
    1. Department of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS18 7DU
      *Please address all correspondence to P. E. Holt
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    • **Department of veterinary Clinical Science and Animal Husbandry, University of Liverpool, Leahurst, Neston, South Wirral L64 7TE


*Please address all correspondence to P. E. Holt

Abstract

The radiographs of 37 incontinent adult male dogs with urethral sphincter mechanism incompetence were compared with those of 28 control dogs to determine if, as in the bitch, differences in bladder neck position and urethral length were implicated in the pathophysiology of urethral sphincter mechanism incompetence. Bladder neck position was significantly different; compared with continent dogs, incontinent animals were significantly more likely (P<0.005) to have intrapelvic than intra-abdominal bladder necks. However, after allowing for the influence of body size, and unlike the situation in the bitch, there was no significant difference in proximal urethral length between the two groups. Bladder neck position was significantly related to prostate size (P<0.001) and it is suggested that this is one reason why castrated male dogs are more prone to urethral sphincter mechanism incompetence than entire animals. A logistic regression analysis revealed that both bladder neck position and castration status were significant risk factors for incontinence and that they appeared to be acting independently of each other.

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