CT imaging of dogs with perineal hernia reveals large prostates with morphological and spatial abnormalities

Abstract

The etiology of canine perineal hernia (PH) remains unclear, although as a disease of older male dogs, it is likely to be hormonal. The role of the prostate in the formation of PH has been questioned; however, prospective and systematic evaluation of prostates in these dogs is absent in the literature. In this prospective case–control study, CT imaging was used to assess prostatic changes in dogs with PH (n = 46) and compare these findings with those of intact age‐matched male dogs (n = 23). Using the OsiriX® DICOM viewer, we measured prostatic volume and correlated it with the size of the dog by using the length of the sixth lumbar vertebra. In addition, we recorded spatial and morphological changes of the prostate, such as heterogenicity, intra‐ and paraprostatic cysts, and mineralizations, as well as prostatic location and rotation. We found that dogs with PH had larger prostates (P < .001) that more often contained cysts (P < .001) and had larger cyst diameters (P = .013) than age‐matched controls. Prostates of PH dogs also contained paraprostatic cysts (17.4%) and focal mineralizations (32.6%), which were absent in the control group. Abnormal rotation and location of the prostate were common in dogs with PH. In conclusion, these findings support the use of CT as an adjunct diagnostic imaging modality for the evaluation of the prostate in dogs with PH. Further studies are needed to evaluate nonprostatic CT findings in the pelvic cavity of PH dogs.

Exploring the association between canine perineal hernia and neurological, orthopedic, and gastrointestinal diseases

“…The hormone relaxin, mainly produced in the prostate in male dogs, is thought to leak into surrounding tissue from a cystic prostate in PH dogs [ 9 ]. This study did not assess the prostate, as CT findings of the prostate were recently published in a separate study, which found PH dogs to have significantly larger prostates than age-matched males, often with cysts [ 20 ].…”

“…This paper is part of a larger research project assessing the etiology and treatment of canine perineal hernia. The population of dogs in the present study also includes a cohort of male dogs from a previously published study [ 20 ]. We excluded dogs that had severe renal, hepatic, or cardiac disease or had an American Society of Anesthesiologists physical status rating of 4 or 5.…”

Dimensional and spatial computed tomographic abnormalities of the rectum and prostate are only partly reversible after surgical repair of perineal hernia in dogs

“…This study is part of a larger project on PH in dogs. 8,15,16 Privately owned male dogs undergoing investigation of PH at the Veterinary Teaching Hospital of the University of Helsinki (VTHUH) were CT scanned before and 3 months after PH repair between 2017 and 2021. Power analysis was conducted to compare the clinical outcomes of two surgical techniques.…”

“…The volume of the prostate was measured with a previously described and validated method. 8,16 Prostate margins were drawn manually on every sequential transverse image, and prostatic volume was then calculated using the software tool. To proportion the prostate volume to the size of the dog, the ratio between the cubic root of the volume to the length of the sixth lumbar vertebra was determined and recorded as ratio volume (RV).…”

“…7 Intact male dogs with PH have been found to have larger, more cystic, and more caudally located prostates than their agematched controls. 8 Increased relaxin activity within the prostate and fluid phase of paraprostatic cysts has been suspected as a reason for atrophy of the muscles of the pelvic diaphragm in PH dogs. 7,9,10 It is not known whether the prostate size or location or the hormonal status of the PH dog could also be associated with dimensional or spatial changes of the rectum.…”