Triaditis: Truth and Consequences

Feline Cholangitis

Inflammatory biliary tract disease (cholangitis) is the commonest liver disease in cats but remains poorly understood. There are chronic lymphocytic and acute neutrophilic forms together with chronic neutrophilic cholangitis which may overlap both these categories. Acute suppurative cholangitis is often associated with bacterial infections and interruptions to bile flow. Lymphocytic forms may be immune-mediated but there is evidence of heterogenicity in histologic and clinical appearance and response to treatment which may suggest several distinct diseases. This review discusses current knowledge, presentation, and diagnosis of feline cholangitis and suggests avenues for future research.

Histologic characterization of the major duodenal papilla and association with concurrent biliary, pancreatic, and intestinal pathology in cats

Conjoining of the major pancreatic duct and common bile duct at the major duodenal papilla (MDP) is suspected to predispose cats to the clinical syndrome of "triaditis." However, microanatomy of the MDP or presence of lesions at the MDP has not been assessed in cats with or without triaditis. The aims of this study were to characterize feline MDP histomorphology and to identify associations between MDP anatomy/disease and the presence of biliary, pancreatic, or intestinal inflammation or neoplasia. Histologic assessment was prospectively performed on the MDP, duodenum, jejunum, ileum, liver, and pancreas from 124 client-owned cats undergoing postmortem examination. The majority of cats (104/124, 84%) had a complex ductular network at the MDP, with no distinction between pancreatic and common bile ducts. Lymphoid aggregates at the MDP were common (63/124, 51%). Inflammation of the MDP (MDPitis) was present in 35 of 124 cats (28%) and was often concurrent with cholangitis, pancreatitis, or enteritis (32/35, 91%), but was only associated with enteritis (19/35, 54%, P < .05). Triaditis was less common (19/124, 15%), but was associated with both conjoined MDP anatomy (19/19, 100%, P < .05) and MDPitis (12/19, 63%, P < .05). Neoplasia was present in 37 of 124 cats (29%), with lymphoma (28/37, 78%) predominating. Enteropathy-associated T-cell lymphoma type 2 (EATL2) was most common (n = 16/37, 43%) and was associated with triaditis and MDPitis (P < .05). These findings suggest that anatomy, immune activation, and/or inflammation of the MDP may play a role in the pathogenesis of triaditis. Further studies are needed to elucidate the relationships between triaditis, MDPitis, and EATL2.

Cholangiopancreatography in cats: a post-mortem comparison of MRI with fluoroscopy, corrosion casting and histopathology

In human medicine, magnetic resonance cholangiopancreatography (MRCP) is a valuable diagnostic tool for hepatobiliary and pancreatic diseases. In veterinary medicine, however, data evaluating the diagnostic value of MRCP are limited. The primary objectives of this prospective, observational, analytical investigation were to assess whether MRCP reliably visualizes the biliary tract and pancreatic ducts in cats without and with related disorders, and whether MRCP images and measurements of the ducts agree with those of fluoroscopic retrograde cholangiopancreatography (FRCP), corrosion casting and histopathology. A secondary objective was to provide MRCP reference diameters for bile ducts, GB, and pancreatic ducts. Donated bodies of 12 euthanized adult cats underwent MRCP, FRCP, and autopsy with corrosion casting of the biliary tract and pancreatic ducts using vinyl polysiloxane. Diameters of the biliary ducts, gallbladder (GB), and pancreatic ducts were measured using MRCP, FRCP, corrosion casts and histopathologic slides. There was an agreement between MRCP and FRCP in measuring diameters of the GB body, GB neck, cystic duct, and common bile duct (CBD) at papilla. Strong positive correlations existed between MRCP and corrosion casting for measuring GB body and neck, cystic duct, and CBD at the extrahepatic ducts' junction. In contrast to the reference methods, post-mortem MRCP did not visualize right and left extrahepatic ducts, and pancreatic ducts in most cats. Based on this study, MRCP with 1.5 Tesla can be regarded as a contributory method to improve the assessment of feline biliary tract and pancreatic ducts when their diameter is >1 mm.

Prevalence of gallbladder sludge and associated abnormalities in cats undergoing abdominal ultrasound

The significance of gallbladder sludge in cats remains largely unknown and has been speculated to be a pathologic finding in cats. The objectives of this retrospective, observational study were to determine the prevalence of gallbladder sludge in the population of cats presenting for abdominal ultrasound; to describe clinical signs, laboratory findings and certain abdominal ultrasound abnormalities; and to compare these findings to cats without gallbladder sludge. One hundred and ninety-two cats were included. Medical records were searched for cats with an abdominal ultrasound performed between October 2014-2015. Signalment, clinical signs, complete blood count, biochemical findings, presence or absence of gallbladder sludge, and hepatobiliary and pancreatic ultrasound findings were recorded. Gallbladder sludge was present in 44% of cats that underwent an abdominal ultrasound. There was no significant difference in age, sex, presenting clinical signs or clinicopathologic variables between the two groups. Gallbladder wall thickening significantly increased the odds of detecting gallbladder sludge (OR-3.7 95% CI 1.4 - 10.0). Gallbladder sludge was not associated with other ultrasonographic abnormalities of the liver, gallbladder, bile duct or pancreas. Gallbladder sludge is common in cats undergoing abdominal ultrasound and appears to be a non-specific finding. The clinical significance of concurrent gallbladder sludge and gallbladder wall thickening present on ultrasound in cats remains to be determined.