History
A 2-year-old 4-kg (8.8-lb) spayed female Yorkshire Terrier was evaluated after being attacked by a wolf-dog hybrid. On physical examination, the patient was quiet, alert, and responsive. The dog had a rectal temperature of 37.9°C (100.2°F), a heart rate of 66 beats/min, and a respiratory rate of 48 breaths/min. No crackles or wheezes were apparent on auscultation of the thorax. The femoral pulses were weak and synchronous with a peripheral blood pressure of 80 mm Hg. Multiple puncture wounds were detected in the dorsolateral mid-abdominal region, bilaterally. The dog had signs of severe pain, particularly over the right-sided wounds. The remaining physical examination findings were unremarkable. An abdominal focused assessment with sonography for trauma (AFAST) scan was performed to detect the presence of intraperitoneal fluid; no intraperitoneal fluid was detected in this patient. Findings on blood gas analysis and PCV were within reference ranges. Injectable opioid and antimicrobial medications and IV fluid therapy were administered before abdominal radiography was performed (Figure 1).
Right lateral (A) and ventrodorsal (B) radiographic views of the abdomen of a 2-year-old 4-kg (8.8-lb) spayed female Yorkshire Terrier evaluated after being attacked by a wolf-dog hybrid.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
Right lateral (A) and ventrodorsal (B) radiographic views of the abdomen of a 2-year-old 4-kg (8.8-lb) spayed female Yorkshire Terrier evaluated after being attacked by a wolf-dog hybrid.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
Right lateral (A) and ventrodorsal (B) radiographic views of the abdomen of a 2-year-old 4-kg (8.8-lb) spayed female Yorkshire Terrier evaluated after being attacked by a wolf-dog hybrid.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Radiographic Findings and Interpretation
The midaspect of the right muscular layers of the abdomen are poorly defined; there is loss of ability to define the fascial planes of the right side of the abdominal wall. In addition, the adjacent subcutaneous tissue contains a pedunculated, oval, smoothly marginated soft tissue opaque structure that communicates with the abdominal cavity at the level of L3. The subcutaneous tissues in this region also have striated soft tissue opacities. In the lateral projection, only 1 of the kidneys could be identified. Within the cranial aspect of the right side of the abdominal wall, at the level of the right thirteenth rib, there is a triangular, soft tissue opaque structure extending into the adjacent subcutaneous tissues from the abdominal cavity (Figure 2). Multifocal, well-defined gas opacities are identified within the subcutaneous tissues of the dorsal and lateral aspects of the muscle layers of the abdominal wall. The cutaneous margin contains defects along the right inguinal region; the subcutaneous tissues are irregularly marginated and heterogeneously increased in soft tissue opacity.
Same radiographic view as in Figure 1 (panel B, enlarged). Notice the poorly defined and discontinuous muscle layers of the right lateral aspect of the abdomen (black arrowhead) at the level of the thirteenth rib with a triangular soft tissue opaque structure extending from the right cranial aspect of the abdominal cavity laterally into the adjacent subcutaneous tissues (white arrowheads). An additional abdominal wall defect was detected more caudally (white arrows), at the level of L3, with protrusion of a pedunculated, oval, smoothly marginated soft tissue opaque structure from the abdominal cavity.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
Same radiographic view as in Figure 1 (panel B, enlarged). Notice the poorly defined and discontinuous muscle layers of the right lateral aspect of the abdomen (black arrowhead) at the level of the thirteenth rib with a triangular soft tissue opaque structure extending from the right cranial aspect of the abdominal cavity laterally into the adjacent subcutaneous tissues (white arrowheads). An additional abdominal wall defect was detected more caudally (white arrows), at the level of L3, with protrusion of a pedunculated, oval, smoothly marginated soft tissue opaque structure from the abdominal cavity.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
Same radiographic view as in Figure 1 (panel B, enlarged). Notice the poorly defined and discontinuous muscle layers of the right lateral aspect of the abdomen (black arrowhead) at the level of the thirteenth rib with a triangular soft tissue opaque structure extending from the right cranial aspect of the abdominal cavity laterally into the adjacent subcutaneous tissues (white arrowheads). An additional abdominal wall defect was detected more caudally (white arrows), at the level of L3, with protrusion of a pedunculated, oval, smoothly marginated soft tissue opaque structure from the abdominal cavity.
Citation: Journal of the American Veterinary Medical Association 251, 7; 10.2460/javma.251.7.783
The radiographic diagnoses included subcutaneous emphysema, deep fascial emphysema, or both; caudally located cutaneous defects, subcutaneous hemorrhage, edema, or cellulitis; and an abdominal wall defect with evisceration of abdominal contents such as mesenteric fat, small intestines, liver, spleen, or right kidney, secondary to traumatic bite wounds.
Treatment and Outcome
An abdominal exploratory surgery was performed because of the radiographically apparent abdominal wall penetration. The right peritoneal recess was empty and did not contain the right kidney or the distal portion of the caudate lobe of the liver. Along the dorsolateral aspect of the right side of the abdominal wall, there were 2 rents with herniation of the entire right kidney and the distal portion of the caudate lobe of the liver. The musculature of the abdominal wall in this region contained multifocal regions of ecchymosis. The remainder of the exploratory surgery was unremarkable. Both the right kidney and caudate lobe of the liver were easily reduced and both deemed viable. A puncture wound was identified in the parenchyma of the kidney with mild to moderate hemorrhage of the retroperitoneal space. A sample for culture was obtained from the area of injury, which revealed scant growth of gram-positive coccobacilli and nonenteric gram-negative bacilli. The dog was empirically prescribed broad-spectrum antimicrobials and pain medication at the time of hospital discharge. Eight days after surgery, the owner reported the dog to be active and clinically normal.
Comments
Traumatic abdominal wall hernias are uncommon in dogs and cats. Hernias can occur after surgery through a failed incision or after a traumatic event.1,2 The location of hernias depends on the direction of the traumatic force and intra-abdominal pressure changes. The most common locations for traumatic abdominal hernias listed in order from most frequent to least frequent include cranial to the pubis, adjacent to the ribs, lateral aspect of the abdominal wall, dorsal abdominal wall attachment to the transverse processes of the lumbar vertebrae, and femoral triangle region.3 It is thought that a substantial force must be applied to cause disruption of the muscle and fascia beneath the skin. Because of the elasticity of the skin, the skin often remains intact, whereas the deep tissue layers are traumatized. Sharp traumatic injuries such as bite wounds may cause herniation in any location of the abdominal wall and often have less cutaneous injury, compared with deeper muscle and fascia injury. Animal bite wounds are more likely to cause multiple hernias in the dorsal or lateral aspect of the abdominal wall,2 such as was seen in the dog of the present report. Tearing, perforation, and laceration of intra-abdominal structures occur frequently with sharp trauma. Therefore, patients with penetrating abdominal trauma should undergo emergency abdominal exploration after stabilization.4 The puncture wound of the right kidney seen in the dog of the present report raised concern for nephritis; however, appropriate measures were taken by administering broad-spectrum antimicrobials. Alternatively, smaller defects of the abdominal wall may incarcerate or entrap herniated contents causing strangulation of various organs. Postoperative complications of abdominal wall herniation reported for dogs and cats include incisional or abdominal wall infection, ventricular arrhythmias, pancreatitis, and acute renal failure.5
Radiography is particularly helpful in evaluation of patients with acute traumatic abdominal hernias. Radiographic signs of skeletal abnormalities, free intra-abdominal gas suggesting perforation of a hollow viscus or peritoneal extension of puncture wounds, or subcutaneous emphysema can be detected. More definitive radiographic signs of abdominal herniation are a discontinuous abdominal wall and apparent absence of an abdominal organ (eg, the kidney in this case). Organ displacement into subcutaneous tissues is the most definitive sign.6
References
1. Gower SB, Weisse CW, Brown DC. Major abdominal evisceration injuries in dogs and cats: 12 cases (1998–2008). J Am Vet Med Assoc 2009; 234: 1566–1572.
2. Waldron DR, Hedlunh CS, Pechman R, et al. Abdominal hernias in dogs and cats: a review of 24 cases. J Am Anim Hosp Assoc 1986; 22: 817–822.
3. Pavletic MM. Abdominal wall hernias. Available at: vetfolio.s3.amazonaws.com/98/7b/42b0291c469caf683a6abc0c104f/standards-of-care-07-03-2005-pavletic-abdominal-wall-hernia-pdf.pdf. Accessed Aug 17, 2017.
4. Smeak DD. Abdominal hernias. 3rd ed. Philadelphia: WB Saunders, 2002.
5. Shaw SR, Rozanski EA, Rush JE. Traumatic body wall herniation in 36 dogs and cats. J Am Anim Hosp Assoc 2003; 39: 35–46.
6. Silverman S, Ackerman N. Radiographic evaluation of abdominal hernias. Mod Vet Pract 1977; 58: 781–785.
