Clinical Exposures: A peritoneopericardial diaphragmatic hernia in a cat


Clinical Exposures: A peritoneopericardial diaphragmatic hernia in a cat

Apr 01, 2004

An approximately 1-year-old, neutered male, domestic longhaired cat weighing 6.5 lb (2.9 kg) was evaluated by the referring veterinarian because of mild dyspnea. About three months earlier, the cat had been adopted as a stray, and the referring veterinarian had treated it for a mild upper respiratory infection. Feline leukemia virus antigen and feline immunodeficiency virus antibody tests had been performed when the cat was adopted and then again six weeks later, and the results were negative each time. The cat had also received a broad-spectrum anthelmintic and had been neutered and vaccinated with no complications.

Physical examination and diagnostic tests

On physical examination, the cat's temperature was 101.3 F (38.5 C), heart rate was 160 beats/min, and respiratory rate was 36 breaths/min. The cat was small in stature and thin; the only other abnormality was slightly muffled heart sounds on the right side.

Figure 1A
The referring veterinarian repeated the FeLV antigen and FIV antibody tests, and the results were negative. A complete blood count revealed a decreased hematocrit (23.6%; normal = 28% to 48%) and lymphocytosis (7.3 × 103 /μl; normal = 1.6 to 7 × 103/μl). The serum chemistry profile abnormalities were hyperphosphatemia (8.9 mg/dl; normal = 2.5 to 7.3 mg/dl), increased alkaline phosphatase (135 U/L; normal = 3 to 80 U/L) and alanine transaminase (396 U/L; normal = 15 to 75 U/L) activities, and a mildly decreased blood urea nitrogen concentration (14.6 mg/dl; normal = 15 to 33 mg/dl). Thyroxine concentrations were normal. Urinalysis revealed a mild increase in specific gravity (1.072; normal = 1.020 to 1.060), hematuria (319 RBCs/hpf; normal = 0 to 2 RBCs/hpf), and proteinuria (1+; normal = negative).

Figure 1B
Lateral and ventrodorsal thoracic radiographs revealed an enlarged cardiac silhouette (Figures 1A & 1B). Differential diagnoses included a peritoneopericardial diaphragmatic hernia, an endocardial cushion defect, congenital heart defects (e.g. patent ductus arteriosus, ventricular septal defects), cardiomyopathy, and pericardial effusion. No murmurs or lung abnormalities were auscultated, and the cat was not exhibiting any other clinical signs. Positive contrast peritoneography using 12 ml diatrizoate sodium was performed, and the lateral and ventrodorsal radiographs revealed contrast media in the abdominal cavity and surrounding the heart (Figures 2A & 2B). These results confirmed a diagnosis of peritoneopericardial diaphragmatic hernia.

Figure 2A
The decreased hematocrit, hyperphosphatemia, and increased alkaline phosphatase activity may have been related to the cat's age, and the mild lymphocytosis was consistent with an excited, young cat. The elevated alanine transaminase activity and decreased blood urea nitrogen concentration may have been related to hepatic inflammation associated with displacement. The hematuria may have been due to traumatic cystocentesis.

Figure 2B
The referring veterinarian also performed an abdominal ultrasonographic examination, and it revealed liver tissue adjacent to the heart, within the pericardium. The cat was referred to Veterinary Surgical Services for surgical correction of the peritoneopericardial diaphragmatic hernia.