Scrotal herniation in a dog
Keywords: hernia, scrotum, canine, testicle, Clumber, omentum
Note: In this case, the images are at low resolution, suitable for web use only.
A 5 year old a Clumber spaniel was presented with acute swelling of the left side of the scrotum. He was bright alert and responsive.
Ultrasonography demonstrated a substantial volume of non- echogenic fluid (clotted blood is highly echogenic) around the left testicle.
The testicle itself was not enlarged but could not be palpated, presumably because of fluid surrounding it. There did not appear to be any intestines within the tunica vaginalis. The right testicle was clearly palpable in the right half of the scrotum. Strongly echogenic masses could be seen adjacent to the spermatic cord in the proximal portion of the scrotum. These were presumed to part of the hernia, possibly omental fat.
The blood flow in the spermatic cord was measured using Doppler flow rate and found to be slower than the flow rate in surrounding vessels:
There was no abdominal fluid visible by transabdominal ultrasonography therefore it was presumed to be limited to the tunica vaginalis in the scrotum. Under ultrasonographic guidance, approximately 70 ml of sero-sanguinous fluid was aspirated from the tunica vaginalis.
Culture and sensitivity and cytology did not reflect an inflammatory process.
During surgery, the entire left external vaginal tunic was exposed then incised proximally, revealing a portion of healthy omental fat in the area adjacent to the external inguinal opening. After careful inspection for the presence of intestinal loops, the vaginal tunic was transected distal to healthy omental fat. The external vaginal tunic was removed. It containing the hernia, the left testicle, and a substantial volume of sero-sanguinous fluid.
Dissection of the tunica vaginalis revealed that an omental tag had slipped into the left inguinal opening, lodging in the vaginal cavity causing swelling and vascular embarrassment.
As the blood vessel walls became weakened due to anoxia, a transudate of sero-sanguinous fluid had accumulated in the vaginal cavity.
Histological examination of the left testicle showed that spermatozoa were still present in the seminiferous tubules.
However, there was evidence of sloughing of the seminiferous epithelium, a sign that is consistent with acute hyperthermia in testicles. Chronic hyperthermia will result in complete suppression of spermatogenesis.
Although inguinal-scrotal hernias are known to be heritable in some farm species and in several breeds of dogs, inguinal hernias have not been recognized as a heritable defect in Clumber spaniels
(http://www.avar.org/avar_dog_genetic_diseases.pdf. ). This suggests that this is not a common problem in this breed. Future litters from this male many show that he should not have been used for breeding (excellent compensatory hyperplasia usually occurs in the remaining testicle in such cases). However, until such data is generated, one can only presume that this defect was an accidental, isolated incident.
