Tumors of the skin (eg, mast cell tumor), soft tissue (eg, sarcoma), or bone (eg, osteosarcoma) can occur along the tail. Depending on the location, adequate margins can be achieved via tail amputation (ie, caudectomy). Primary excision of skin tumors on the tail may lead to tension along the closure and can increase the risk for a tourniquet effect or dehiscence. Tail amputation should be considered for any malignant skin tumors to achieve both adequate margins and tension-free closure.
Another common indication for tail amputation is repeated self-trauma (mostly seen in dogs) caused by hitting the distal tail, sometimes forcibly, on surrounding structures. These repeated incidents can create scar tissue and more friable skin and lead to increased risk for future trauma, bleeding, and a nonhealing wound. Tail amputation should be considered in recurrent cases in which conservative (eg, bandaging) or behavioral management does not allow the wound to heal or prevent recurrence. The goal for these cases is not to amputate the entire tail but to shorten it enough to preclude recurrent self-damage.
Tail trauma in hunting dogs has been described.1 Vehicular accidents can cause degloving wounds of the tail similar to appendicular trauma. Wounds can be sutured and closed in some cases, but if there is not enough skin to allow tension-free closure, tail amputation may be preferable.
Tail vertebrae are surrounded by closely attached dorsal (sacrocaudalis dorsalis lateralis and medialis), ventral (sacrocaudalis ventralis lateralis and medialis), and lateral (intertransversarius dorsalis caudalis and intertransversarius ventralis caudalis) bulky muscles. The main blood supply can be found on both lateral sides of the tail (lateral caudal arteries), with smaller dorsal (dorsolateral caudal arteries) and ventral (median caudal and ventrolateral caudal arteries) arteries.
Complications of tail amputation include bleeding, dehiscence, and infection. Although infection and dehiscence are not common, they may necessitate revision of the amputation to a proximal level and require removal of more proximal coccygeal vertebrae. Bleeding in large dogs can be decreased with an intraoperative tourniquet, depending on its tightness. Temporary intermittent loosening of the tourniquet during surgery allows timely identification of vessels that can then be ligated (larger vessels) or electrocauterized. Alternatively, the tourniquet can be loosened prior to closure to check for appropriate hemostasis. A sterile, self-adhesive bandage can alternatively be placed over or adjacent to the intended incision site if there is enough proximal space. The bandage creates a tourniquet effect when applied tightly, and the incision can be extended into the bandaging. Judicious use of monopolar electrocautery when dissecting muscle off the bone and during muscle transection also decreases hemorrhage (aiding in identification of vessels) and can be used in addition to a tourniquet, especially in large-breed dogs. Individual hemostasis of vessels would still be needed.
Tension-free skin closure reduces the risk for postoperative dehiscence; removal of an additional vertebra can be considered if there is tension. Perioperative placement of an anal purse-string suture can reduce the risk for fecal contamination, as does placing surgery drapes to only include the tail in the surgical field; however, in higher amputations (ie, sacrococcygeal caudectomies), draping the tail base and perineum typically cannot be avoided. Placing tape in a visible place (eg, top of the patient's head) with a reminder that a purse string was placed helps in remembering to remove the purse string postoperatively.
Postoperative incontinence due to traction on the nerves is a concern with amputations at, or close to, the level of the sacrococcygeal junction. A small stump of several coccygeal vertebrae is ideally left to minimize the risk for incontinence; however, if the trauma or tumor are situated more proximally, care should be taken during dissection to avoid traction.
Although postoperative bandaging can protect the tail stump from self-trauma and keep it clean, bandages can slip easily and are often unnecessary. If a bandage is placed, care is needed to not attach the more proximal part too tightly, as a tourniquet effect is possible.