Severe abdominal dog bite wounds in a pregnant cat

Abstract

Bite wounds are one of the most common reasons for admission of cats to veterinary clinics. Appropriate wound management seems to be more important in the successful outcome of bite wound injuries than antibiotic therapy alone. This report describes a heavily pregnant cat that suffered severe abdominal bite wounds necessitating treatment with extensive surgery. A necrotic herniated kidney, abdominal wall hernias, internal peritoneal ruptures and fracture of the thirteenth rib, gravid cornu rupture, an extrauterine dead foetus and its free kidney were all observed at laparotomy. At surgery the extrauterine dead foetus was removed, and two live foetuses were retrieved by en bloc ovariohysterectomy. A right nephrectomy and partial costectomy were also performed. Two weeks postoperatively, the cat had fully recovered without a problem. Bite wounds encountered in cats, though severe and invasive, can be tolerated and extensive surgical management can result in successful outcomes even under suboptimal conditions.

Bite wounds are one of the most common reasons for admission of cats to veterinary clinics (Holt and Griffin 2000). Bite wounds, which comprise 15% of all trauma cases, are the second most common cause of trauma in cats (Kolata et al 1974). However, dog bites in cats are not as frequently encountered as in dogs. Dog bite wounds can range from minor to extremely complex wounds (Neal and Key 1976, Cowell and Penwick 1989, Shamir et al 2002).

No standard protocol is available for the treatment of bite wounds in dogs and cats (Shamir et al 2002). The results of diagnostic tests may assist in making decisions regarding whether to treat surgically or medically, particularly when a patient fails to respond to medical treatment alone (Dye 2003). In cases with crushing and penetrating abdominal injuries, immediate surgical intervention including initial debridement and exploratory laparotomy is recommended as soon as the patient has been stabilized (Neal and Key 1976, Cowell and Penwick 1989, Harari 1993, Davidson 1998a, Holt and Griffin 2000) and this may be necessary for survival (Dye 2003). This report describes the management of a pregnant cat approaching parturition that was attacked by four dogs, resulting in severe abdominal bite wounds. It was treated with extensive surgical management.

A 2-year-old female crossbreed free-roaming cat was referred by a veterinary practitioner to the Emergency Veterinary Clinic of the Uludag University. The cat had sustained severe dog bite wounds and had been treated with antibiotics for 2 days. On physical examination, the cat was lethargic with signs of circulatory shock. On the right flank, there was serous discharge from several bite wounds and a swelling due to a subcutaneous mass (later identified as the herniated right kidney) was observed at surgery. Ultrasonographic examination revealed two foetuses that were estimated as 55 days of age (according to body dimensions) and one further foetus that could not be definitely identified as being in the uterus. Lateral abdominal radiographs confirmed the presence of three foetuses. According to the anamnesis and observation in the preoperative period, the cat was urinating normally and the urine looked grossly normal on the ultrasonography of the bladder confirmed normal urine production. The urine analysis was not performed due to the emergency circumstances.

The cat was initially administered lactated Ringer's solution (Laktatli Ringer; Polifarma) at 20 ml/kg/h intravenously before anaesthetic induction and then it was continued on 0.9% sodium chloride at 10 ml/kg/h (Sodyum Klorur; %0.9 Anonim) and Dextran 70 at 5 ml/kg (Dekstran-70; IE Ulagay) during the operation. Subcutaneous carprofen (Rimadyl; Pfizer) was given at a dose of 4 mg/kg for preoperative analgesia and repeated after 24 h at 2 mg/kg q12 h twice postoperatively. The anaesthesia was induced intramuscularly with 1.1 mg/kg xylazine (Alfazyne 2%; Alfasan International BV) and 10 mg/kg ketamine hydrochloride (Alfamine 10%; Alfasan International BV) at 20-min intervals, respectively. Use of xylazine or xylazine–ketamine combinations should probably be avoided in patients presented for caesarean section (McDonnell and Van Gorder 1982) and in dogs presenting with acute abdomens (Hofmeister 2003). However, in this case it was given due to the lack of the facilities of the night service emergency clinic to maintain the cat on gaseous anaesthesia. The anaesthesia was maintained with a combination of 5.5 mg/kg ketamine and 0.3 mg/kg diazepam (Diazem; Deva) intravenously at 30-min intervals.

A dorsoventral incision in the right flank revealed that the right kidney was in a subcutaneous position and strangulated and incarcerated on each side by ruptured muscle. It was congested, black and there was a two-fold increase in size (Fig 1). After entry into the abdominal cavity, an extrauterine dead foetus, with a perforated abdomen and a free floating kidney, was found and removed. En bloc ovariohysterectomy was necessary because there was a ruptured and necrotic right uterine horn; two live foetuses were delivered from the left horn (Fig 2). After confirming that the left kidney appeared to be intact, nephrectomy of the right kidney was performed. Prior to closing the abdomen, four ruptures of both the peritoneum and muscles were identified and sutured. The abdominal cavity was flushed with 20 mg/kg rifamycin in saline (Rif 250 mg; Kocak) because of the risk for the development of peritonitis after penetrating bite wounds. Another skin incision was made in a horizontal ‘T’-shape on the right thoracic wall (Fig 3) revealing a fractured thirteenth rib: a partial costectomy was performed to remove the fractured portion. Further muscle and peritoneal tears were identified and sutured in a similar manner to those involving the right flank.

Fig 1.

Necrotic herniated right kidney (arrow).

Fig 2.

Necrotic herniated right kidney (a), ruptured right uterine horn (b), and intact gravid left horn (c).

Fig 3.

Postoperative appearance of dorsoventral flank (a) and horizontal ‘T’-shape (b) skin incision.

The peritoneum and abdominal muscles were sutured with interrupted cruciate sutures and the subcutaneous connective tissues were closed with simple continuous sutures using polyglactin 910 (Vicryl, Ethicon) number 1. The cat took 45 min to prepare, for surgery and the surgical intervention lasted 1 h 50 min. Postoperatively, the cat was given intravenous lactated Ringer's solution with 5% glucose (Ringer Laktat+%5 Dekstroz; Anonim) administered at a rate of 20 ml/kg, and 20 mg/kg ampicillin–sulbactam (Ampisid; Mustafa Nevzat) was given intramuscularly, twice daily for 7 days. After 2 days of hospitalisation, the cat was referred back to the practitioner for postoperative care and then seen back at the Uludag University after 12 days. At the recheck examination, the cat was in normal health; however, the owner reported that one of the kittens had died 5 days postoperatively. Any complication of the operation was not observed following 8 months (Fig 4).

Fig 4.

Cat's appearance after 8 months.

In this case, the mild nature of the external skin lesions misled the referring practitioner to the severity of the abdominal lesions, which led to insufficient treatment. Despite small teeth marks on the skin which appear innocuous, the formation of punctures, ruptures, avulsions, and crushings may occur, causing extensive damage to muscles, vasculature and internal organs. This is known as the iceberg effect (Davidson 1998a). In one study wound management seemed to be more important in the successful outcome of bite wound injuries than did antibiotic therapy (Davidson 1998b). The cat's loose skin and subcutaneous tissues allow dogs' teeth to move more freely, which explains the severe damage and penetration of the abdominal cavity; thus, bites can result in life-threatening injuries (Holt and Griffin 2000).

Bite wounds are responsible for 40% of feline hernias (Shaw et al 2003), which can also occur by formation of separated (McKiernan et al 1984) or fractured ribs. In such so-called autopenetrating hernias, the abdominal wall is penetrated by the jagged costal remnant (Ganchi and Orgill 1996, Shaw et al 2003). In the present case, the penetration and perforation of the abdominal wall by the fractured rib was not recognised until the time of intraperitoneal flushing. Herniation of the right kidney was also not recognised during the initial examination due to the high mobility and palpability of cats' kidneys normally (Shaw et al 2003). Determining the number of foetuses by ultrasound can also be deceptive and, therefore, results should be supported by radiography.

In contrast to a former report (Webb 1972), uterine rupture is reported to occur more frequently in cats than in dogs, either as an incidental finding or as a subsequent cause of dystocia or illness (Hayes 2004) and also as a sequel to external abdominal trauma (Wilkinson 1951, Godfrey 1997). Extrauterine dead foetuses in cats subsequent to dog bite wounds have only been reported by Tirgari (1986) and Palmer (1989), although the latter's cause was only conjecture.

Bite wounds encountered in cats, though severe and invasive, can be tolerated and extensive surgical management can result in successful outcomes even under suboptimal conditions. In the cat in this report, there was rapid healing of severe intra-abdominal injuries after extensive surgical management, which supports this conclusion.