A challenging case: Abdominal effusion in a dog

Leakage of intestinal contents and a common contrast medium into a dog's abdominal cavity proved to be a fatal combination.
source-image
May 01, 2009


Vital Stats
A 7-year-old 11.7-lb (5.3-kg) spayed female Cairn terrier was presented to the University of Florida Veterinary Medical Center for evaluation of pain on abdominal palpation and anorexia of four days' duration. Seven days before presentation, the patient had undergone a cystotomy for calcium oxalate urolith removal at a referring veterinarian's clinic. Two days before presentation, a gastrointestinal series had been performed at the same referring veterinary clinic for evaluation of abdominal pain and vomiting to rule out a gastrointestinal foreign body obstruction, but no abnormalities had been identified.

INITIAL PRESENTATION AND EVALUATION

At presentation, the dog had normal vital signs but was lethargic with a tense abdomen and palpable abdominal fluid. The combination of the presenting signs with the history of a recent cystotomy raised suspicion for a possible uroabdomen secondary to surgical complications. An abdominocentesis yielded 12 ml of an opaque straw-colored fluid with a protein concentration of 3.2 g/dl, a red blood cell (RBC) count of 190/μl, and a white blood cell (WBC) count of 46,150/μl.

Cytologic examination


Figure 1. Cytologic examination of abdominal fluid from the dog in this case reveals a neutrophil containing an intracellular bacterium (short arrow) and refractile granules of barium sulfate (long arrow). Barium sulfate granules are also noted in the background (Wright's-Giemsa; 100X).
Cytologic examination of direct smears of the abdominal fluid revealed numerous cells and a pale basophilic granular background consistent with highly proteinaceous fluid. A 200 differential cell count yielded 99% neutrophils and 1% mononuclear phagocytes. The neutrophils were markedly karyolytic with occasional intracellular bacilli and numerous small, round-to-oval, pale-yellow refractile particles consistent with barium sulfate granules (Figure 1). The refractile material was also observed extracellularly in the background. The mononuclear phagocytes were moderately reactive. No neoplastic cells were identified. The cytologic interpretation was septic exudate containing material consistent with barium sulfate granules, suggesting leakage from the gastrointestinal tract.

Additional diagnostic tests

The complete blood count (CBC) results revealed a normal packed cell volume (PCV) of 45% (reference range = 37% to 54%) and a normal total WBC count of 14,230/μl (reference range = 6,000 to 17,000/μl) that was characterized by a mild left shift and 2+ toxic neutrophils. The serum chemistry profile revealed increased alkaline phosphatase (ALP) (496 U/L; reference range = 16 to 111 U/L) and aspartate aminotransferase (AST) (68 U/L; reference range = 10 to 46 U/L) activities and decreased concentrations of albumin (2 g/dl; reference range = 2.9 to 3.7 g/dl) and calcium (8.9 mg/dl; reference range = 9.5 to 11.6 mg/dl). The CBC results, increased liver enzyme activities, and decreased albumin concentration indicated active inflammation with possible infection. The hypocalcemia was attributed to the low albumin concentration.


Figure 2. A right lateral thoracic radiograph of the dog reveals free contrast medium in the abdomen (short arrow) and contrast medium uptake in the sternal lymph node (long arrow).
Thoracic and abdominal radiographic examinations identified free barium in the abdomen and in the sternal lymph node, which supplies lymphatic drainage for the abdomen (Figure 2).

Glucose concentrations measured in the serum (143 mg/dl; reference range = 70 to 122 mg/dl) and abdominal fluid (80 mg/dl) and lactate concentrations measured in the serum (2.1 mmol/L; reference range = 0.22 to 1.44 mmol/L) and abdominal fluid (6.1 mmol/L) were consistent with a septic peritoneal exudate. A difference of > 20 mg/dl between serum and abdominal fluid glucose concentrations and a difference of < -2 mmol/L between serum and abdominal fluid lactate concentrations are suggestive of a septic exudate in the abdomen.1 Consequently, a presumptive diagnosis of septic barium peritonitis secondary to gastrointestinal perforation, source unknown, was made.