Surgical treatment of perineal hernias in male dogs: the correlation between castration, recurrence and urinary incontinence
Summary
Objectives: Perineal hernias are most common in intact male dogs. Surgical repair of the
hernia is the recommended method of treatment. There is a suspicion that recurrence of
perineal hernias after herniorraphy is associated with neutering status of the dog. The effect
of castration on preventing recurrence of perineal hernias has been described in several
studies. The obtained results were inconclusive. Perineal hernias can cause a great variety of
clinical signs. Studies regarding the correlation between herniorraphy and castration in
relation to the occurrence of urinary incontinence are limited. This study was set up to
investigate if the incidence of recurrence of perineal hernias after herniorraphy differs
significantly between castrated and intact male dogs and if the incidence of urinary
incontinence after castration and herniorraphy is significantly higher than the incidence of
urinary incontinence after castration without perineal hernia surgery. Finally, we made an
effort to confirm the expectation that neutered male dogs with a perineal hernia are
predisposed for urinary incontinence.
Material and methods: In this retrospective study the medical records of all male dogs
surgically treated for a perineal hernia at the Department of Clinical Sciences of Companion
Animals of Utrecht University between January 2005 and June 2015 were reviewed. Patient
owners were contacted by telephone and asked to fill in a digital survey regarding the followup
period.
Results: 113 male dogs were surgically treated for a perineal hernia at the Department of
Clinical Sciences of Companion Animals of Utrecht University between January 2005 and June
2015. Eight dogs (7.1%) remained intact during the entire follow-up period. Sixteen dogs
(14.2%) were neutered prior to the first herniorraphy, 65 dogs (57.5%) during the surgery and
6 (5.3%) after surgery. Only one of the dogs was chemically neutered. In 17 dogs (15%)
neutering status was unknown. Recurrence occurred in 25 dogs (22.1%). Recurrence was seen
in 17% of the neutered dogs and 62.5% of the intact dogs. Statistical analysis showed that the
difference between both groups was significant (P = 0.009). Information regarding urinary
incontinence was available for 64 dogs. Urinary incontinence was seen in eight of these dogs
(12.5%). Six dogs were neutered prior to the occurrence of urinary incontinence. The
remaining two dogs were intact at the time of first occurrence of urinary incontinence.
Statistical analysis showed no significant association between neutering status and the
occurrence of urinary incontinence (P = 0.312).
Conclusion: The incidence of recurrence of perineal hernias after herniorraphy is significantly
higher in intact male dogs compared to neutered male dogs. There is no significant association
between occurrence of urinary incontinence after herniorraphy and neutering status. Urinary
incontinence may be more common in neutered dogs with perineal hernia than in healthy
neutered dogs, but a prospective study with a control group is necessary to confirm this
theory.