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
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).
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.
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.
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.