Facial Wound Reconstruction in a Chihuahua: A Pictorial Essay
Ashley Magee, DVM, DACVS
Figure 1: Jax in his yard before the incident.
Figure 2: Jax at admission. Note loss of the chin and rostral
portions of the lower lips.
A one-year-old male neutered Chihuahua, Jax, was playing in his yard on a warm summer evening (Figure 1). While sniffing through the slots in the fence, he was bitten by the neighbor's large breed dog, suffering a severe avulsion injury of the ventral mandibular skin. The clients immediately took Jax to their primary care clinician who assessed the wound, administered pain medications and referred him to DoveLewis Emergency Animal Hospital for surgery.
On presentation, Jax was quiet and assessed to be in early compensatory shock. Several incisors were missing and several teeth were loose but the mandible appeared stable with no fractures detected. Mild active bleeding was present. The entire chin and ventral mandibular skin along with the lateral aspects of both lower labia were missing (Figure 2). An IV catheter was placed and a complete blood count and serum chemistry performed revealing mild hemoconcentration (PCV 57%, TS 7.0 mg/dl) Hypernatremia (Na+ 161 mg/dl) and elevated BUN (32 mg/dl). Jax’s wound was gently lavaged with warm saline then a culture sample taken from the wound and reserved for possible submission. He was started on intravenous ampicillin sulbactam at 30 mg/kg IV q 8 h and isotonic fluids at approximately 2 x maintenance rate were started after an initial 8 ml/kg bolus. Maropitant 1 mg/kg was given. Hydromorphone at 0.1 mg/kg was continued every four hours for pain control and heat support initiated as Jax waited for his surgical consultation later that evening. Due to location, the wound could not be bandaged so sterile water soluble lubricant was placed in the wound every hour until assessment by the surgeon.
Later that evening, Jax was anesthetized and intubated for his surgical consultation. Although extensive, the wound was clean and no mandibular fractures were appreciated. Occlusion was normal. The two central incisors were missing and the others were loose, but canine teeth were stable. After copious lavage, paired advancements of the remaining caudal mandibular skin and labiae were used to cover as much of the degloved area as possible, attaching the skin at the level of the canines to the gingiva and periosteum where possible, followed by a two layer closure. A penrose drain was placed in the most dependent point at the base of the flap in the caudal mandible (Figure 3a, b). The rostral incisor area was left open to granulate in rather than place excessive tension on the skin flap, as further reconstructive procedures were expected. The advancement did move the labial commissures considerably more rostral, but ability to open the mouth did not appear to be compromised.
Jax recovered uneventfully from his procedure. Post-operative blood work showed resolution of hypernatremia, elevated BUN and hemoconcentration. The clients were counseled that Jax would likely need additional reconstruction of the rostral incisor area, as well as to have the remaining incisors extracted. Jax recovered well and was able to eat the following morning and was discharged the following day. The surgical site was intact and he had developed soft submandibular edema. Medications included a liquid medication regime of clindamycin, meloxicam, and gabapentin. A fentanyl patch was also placed. The clients were instructed to use an e-collar at all times to prevent self trauma to the surgical site, to feed soft food and to avoid any interaction with other pets. A recheck was scheduled with the surgery service in three days’ time for drain removal. On postoperative day three, Jax presented for drain removal. The peri incisional edema had resolved and no active fluid egress was apparent from the drain. The exposed tissue at the level of the chin was scabbed over and remaining incisors noted to be stabilizing. The drain and fentanyl patch were removed. Culture returned few Pasteurella species. Since no evidence of active infection was found, antibiotic regimen was not changed.
Figure 3a: Jax immediately post-operatively.
Figure 3b: Jax immediately post-operatively.
Jax returned on postoperative day 14 for recheck and skin suture removal. Jax was BAR and friendly. Most of the surgical repair had healed primarily with minor tissue die-off; the rostral extent was healing with healthy granulation tissue and surrounding epithelialization was occurring (Figure 4). Laxity in the incisors was only subtle. Jax’s sutures were removed. Reevaluation for further reconstruction was scheduled for week six. The clients were instructed to transition Jax back to dry food but still avoid chew or tug toys.
Figure 4: Jax two weeks post-operatively.
Figure 5: Jax six weeks post-operatively at final recheck.
Jax’s final recheck was six weeks after his initial wounding. His rostral chin area was completely epithelialized and the remaining incisors appeared healthy, immobile, and the gap left by the avulsed incisors had closed in . At this point, any need for further reconstruction was deemed unnecessary unless the clients wished to improve cosmesis (Figure 5). Over weeks 6-10 the cosmesis continued to improve with return of some darker pigmentation and continued contraction of the epithelialized scar tissue. The clients were very pleased with the final result and his adorable, toothy smile! (Figure 6a, b).
Figure 6a: Jax 10 weeks post-operatively.
Figure 6b: Jax 10 weeks post-operatively.