Feline Pancreatitis

Pancreatitis is the most common feline exocrine pancreatic disorder.^1,2 Cats with pancreatitis can present with a variety of nonspecific clinical signs, including lethargy, anorexia, and weight loss, depending on the chronicity and severity of the disease.^2,3

Vomiting and abdominal pain, typically seen in dogs with pancreatitis, are less common in cats.³ Most cases of feline pancreatitis are idiopathic, although it can be associated with various concurrent diseases, including hepatic lipidosis, cholangiohepatitis, inflammatory bowel disease, infectious disease, drug intoxication, and abdominal trauma.^1,3,4

The nonspecific clinical presentation and pathologic findings of feline pancreatitis make diagnosis difficult.^5,6 Ultrasonography has been suggested as a useful diagnostic technique to detect pathologic changes in the feline pancreas⁷; however, the sensitivity of ultrasonography for feline pancreatitis is low and has been reported as only 10% to 35% when performed by a board-certified ultrasonographer.^5,8 Reported ultrasonographic findings associated with pancreatitis include hypoechogenicity of pancreatic parenchyma, hyperechogenicity of surrounding mesentery, pancreatic enlargement, and peritoneal effusion.^4,9,10

The sensitivity of computed tomography (CT) in cats with pancreatitis has been reported to be lower than that of ultrasonography.¹¹ Abdominal radiographs are also considered nonspecific for the diagnosis of pancreatitis in cats but may show peritoneal effusion when pancreatitis is severe.^2,7

Sagittal (1A) and transverse (1B) ultrasound images of a healthy 9-month-old castrated domestic short-haired cat. In the sagittal plane, the stomach (S) is cranial to the left lobe of the pancreas (arrows), which is smoothly marginated with a thin, centrally located pancreatic duct (arrowhead).

The pancreas can extend laterally to the level of the left kidney and spleen. In the transverse plane, the liver (L), duodenum (D), and right lobe of the pancreas (arrows) are identified. Again, note the smooth pancreatic margins and thin, centrally located pancreatic duct (arrowheads).

Lateral (2A) and VD (2B) radiographs of the abdomen of a 6-year-old spayed domestic long-haired cat with vomiting, diarrhea, and a fever; the patient was diagnosed with pancreatitis via ultrasound (not shown).

The liver (L) is enlarged and there is a central loss of serosal detail (*) ventral to the kidneys (K) and caudal to the stomach (St) on the lateral view (2A) and between the stomach (St), left kidney (LK), and spleen (Sp) on the VD view (2B).

Case 1—Ultrasound images of a 3-year-old spayed domestic short-haired cat with lethargy and vomiting; the patient was undergoing chemotherapy for lymphoma of the GI tract and abdominal lymph nodes with bone marrow involvement.

Fine-needle aspiration of the pancreas with a 25-gauge needle identified mixed-cell pancreatitis with necrosis; cytology of the pancreas was performed to rule out neoplastic involvement. Note: The authors have identified lymphoma and mast cell tumors in the pancreas of other patients and do not hesitate to aspirate the pancreas in this type of case. The sagittal (3A) image shows the enlarged, hypoechoic pancreas (arrows) dorsal and caudal to the stomach (St). The duct is more prominent (arrowheads). This image is in the same scan plane orientation as Figure 1A. Transverse (3B) image shows the right lobe of the pancreas (arrows) medial to the liver (L) and duodenum (D) and alone in a sagittal plane (3C). The pancreas is irregular in shape, enlarged, and surrounded by heterogeneous fat. The sagittal image shows extreme heterogeneity of the pancreas as well as abnormal shape and size.

Case 2—Transverse (3D) ultrasound image of a 14-year-old castrated domestic short-haired cat with small cell lymphoma of the GI tract shows an irregularly shaped and heterogeneous right pancreatic lobe (arrows) medial to the duodenum. Sagittal (3E) ultrasound image of the pancreas shows hypoechoic pancreatic tissue ventrally (arrowheads) but a mass effect dorsally (arrows) surrounded by attenuating hyperechoic fat.

Cytology of the pancreatic mass effect showed marked suppurative inflammation and necrosis.

Case 3—Sagittal (3F) ultrasound image of a 2-year-old spayed domestic short-haired cat with weight loss and inappetence shows an abnormally hypoechoic, striated pancreas (arrows) and anechoic effusion (arrowheads), both caudal to the stomach (St). There is hyperechoic fat dorsal to the pancreas. Some patients with more severe pancreatitis develop peritoneal and sometimes pleural effusion.  

Normal (4A) CT image of a feline pancreas (arrows). Axial (4B) CT image of the cranial abdomen of a cat with pancreatitis: The pancreas (P) is enlarged and irregular in shape; normally it is flatter and more smoothly marginated. Nearby organs include the stomach (St) ventrally and spleen (Sp) on the patient’s left, along with the duodenum (D), right kidney (RK), and portal vein (*)

on the patient’s right. CT images by tradition are interpreted with the patient’s left (L) side on the viewer’s right side, as when reviewing a VD radiographic image.

Case 1—Lateral (5A) and VD (5B) abdominal radiographs of a 10-year-old castrated domestic short-haired cat with inappetence and weight loss; the cat was also icteric on examination. Note the increased opacity and loss of serosal detail in the central abdomen caudal to the enlarged liver (L) and stomach (St), ventral to the kidneys (K), cranial to the colon (C), and medial to the spleen (Sp). Ultrasound images (not shown) revealed a diffusely enlarged pancreas; cytology identified pancreatic carcinoma.

Case 2—Sagittal (5C) ultrasound of a 14-year-old spayed domestic short-haired cat with vomiting and weight loss. Dorsal to the duodenum (D) is a smoothly and distinctly marginated mass (M) in the right pancreatic lobe; this is not typical of pancreatitis, so fine-needle aspiration was performed, which yielded pancreatic carcinoma on cytology. A metastatic lesion in the liver was also confirmed cytologically.

JEAN K. REICHLE, DVM,MS, DACVR, practices at Animal Specialty & Emergency Center in WestLos Angeles, California; prior, she served on the faculty of Ohio State University for 3 years. Dr. Reichle’s special interests include small mammal imaging, especially in patients with elbow dysplasia. Dr. Reichle graduated from Ohio State University and completed an internship at VCA West Los Angeles Animal Hospital before completing her radiology residency and MS degree at Colorado State University.

AMY E. FELUMLEE, DVM, is completing an internship in diagnostic imaging at Animal Specialty & Emergency Center in West Los Angeles, California. She earned her DVM from Kansas State University and will be a veterinary radiology resident at Colorado State University Veterinary Teaching Hospital starting summer 2012.