Hernias[1]
Umbilical hernias can be congenital or acquired. Frequency varies between breeds but is around 1% across the species. Common causes of acquired herniation in piglets are poor umbilical cord management, umbilical infection, and navel sucking by littermates. Iodine dipping at birth can help reduce incidence of infection. Females are at higher risk of developing an umbilical hernia. Surgical treatment proceeds as it would in a calf: The pig is placed in dorsal recumbency, ideally in a V-shaped trough. After aseptic preparation of the surgical site, the hernia sac is isolated and dissected down to the hernial ring.
If surgery is on a male, the prepuce, preputial diverticulum, and penis will need to be reflected laterally or caudally. The hernial sac, and abscess (if present) should be removed. Freshen the edges with a Metzenbaum scissors. Manually break down any adhesions between the hernial sac and intestines. Assess the viability of the bowel, and resect and anastomosis as needed. Close the abdominal defect with a simple continuous pattern and absorbable suture of appropriate size for the animal. Replace and suture prepuce, preputial diverticulum, and penis and suture them to the abdominal wall with interrupted absorbable sutures.
If correcting an umbilical hernia in a female, an elliptical incision is made around the hernial sac. Excess skin is removed. Excise the hernial sac with sharp and blunt dissection. Freshen the edges with a Metzenbaum scissors and close the abdominal wall defect as in the male. Close the subcutaneous tissue and skin in a routine manner with surgeon’s preference of patterns and suture. For both male and female pigs, systemic antibiotics should be administered for at least 5 days.
Inguinal and scrotal hernias have an overall prevalence of 1% in swine. They appear to be strongly heritable as well, with higher incidences in Duroc, Landrace, and Yorkshire pigs, with incidence around 30%. Differentials for inguinal and scrotal hernias include testicular hematoma, scirrhous cord, and hydrocele. Ultrasound and digital palpation are useful means for differentiating. If a hernia seems less likely, needle aspiration can also be used for differentiation. Surgical repair of the hernia is easier if the pig has not yet been castrated. Depending on the surgeon’s comfort level and anticipated surgical time, this could be completed with just injectable anesthesia or with the addition of gas anesthesia. Either way oxygen should be supplied during the procedure. The procedure is performed in dorsal recumbency, ideally with the hind end elevated to allow gravity to assist. Following aseptic preparation of the surgical site, an oblique incision is made over the affected superficial inguinal ring. Once through the skin, the subcutaneous tissue can be bluntly dissected. Isolate the tunica vaginalis via blunt dissection as well, but do not cut through it. Keeping the tunica vaginalis intact is important for keeping the intestines contained. With external pressure on the scrotum, the tunics are gently pulled free from any scrotal attachments. The tunic and testis are then gently twisted to force the intestines back into the peritoneal cavity. The spermatic cord and tunics should be transfixed as close to the superficial inguinal ring as possible. The spermatic cord and tunic can then be cut. The superficial inguinal ring is then closed with either interrupted or horizontal mattress sutures with an absorbable suture material. Proper closer can be confirmed by applying gentle pressure to the abdomen to see if the intestines herniate again. The skin is then closed with absorbable sutures and an intradermal or external pattern. The contralateral inguinal ring should then be inspected to rule out bilateral herniation. Upon completion of any hernia surgery, castration should be performed.
