Topic 22 - Gallbladder and biliary tract diseases in dogs and cats Flashcards
Anatmomy of the gallbladder/bilary duct of DOG
2 pancreatic ducts, separated by the bile duct
= parenchymal disease is more common
Anatmomy of the gallbladder/bilary duct of CAT
Bile duct joins major pancreatic duct
= biliary disease is more common
Name diseases of gallbladder and biliary tract:
- Cholangitis
- Cholestasis
- Triaditis
Cholangitis
Definition
Types
Definition: Inflammation of the biliary tract
Types: Neutrophilic, lymphocytic, (liver fluke initated cholangitis - not very common!!)
Cholestasis
Definition
Decreased flow of bile
Can be due to decreased hepatocyte secretion, intrahepatic or extrahepatic bile duct obstruction
Triaditis
Definition
The bile duct in cats connect to the pancreatic duct before entering the dudodenum, which will cause: cholangitis, pancreatitis, duodenitis = triaditis
Dogs have separate pancreatic duct and insert separately to bile duct
Acute neutrophilic cholangitis
Definition
Very sick dog with jaundice
Always thought to be an ascending bacterial infection from duodenum, causing infection and inflammation. Today the infection isnt alwasy ascending. It has been discovered that the bacterial translocation can occur via wall of GIT or via the blood, and not only through the oddis spinchter
Oddis spinchter = the muscular valve surrounding the exit of the bile duct and pancreatic duct into the duodenum.
Acute neutrophilic cholangitis
Clinical signs
- Young animals = very ill
- Fever, vomiting, diarrhoea, dehydration, anorexia, lethargy, abdominal pain
- Icterus
Chronic neutrophilic cholangitis
Definition
Mixed infection.
Infection in the cells in the epithelium of the bile ducts, slightly sorrounding the bile duct and the portal region. The inflammation causes biliary fibrosis and hyperplasia, causing cholestasis
Chronic neutrophilic cholangitis
Clinical signs:
Cause:
Clinical signs: Older animals the symptoms are not very clear, but icterus will appear - the prognosis is bad when the icterus kicks in.
Cause: Before:unkown, Now: found fragments of bacteria in the epithelium
How to diagnose neutrophilic cholangitis
- CBC
- Ultrasound
- FNA
- Liver biopsy
- Histopathology
CBC for neutrophilic cholangitis
= complete blood count
Useful for acute neutrophilic cholangitis only, causing a increase in ALKP, GGT and mild increase in ALT, AST with increased bilirubin and bile acids
Ultrasound for neutrophilic cholangitis
Can see a distended gall bladder
Pancreas wil be enlarged due to triaditis
FNA for for neutrophilic cholangitis
= Fine needle aspiration
Can do a bile culture to check for bacteria.
BUT: healthy bile could contatin some bacterial fragments
Liver biopsy for for neutrophilic cholangitis
We use laporascopy or laporatomy
Histopathology for for neutrophilic cholangitis
Can see intrahepatic cholestasis with distended bile duct and periportal region with some necrosis
Acute: oedematous portal triad
Chronic: bile duct fibrosis
Lymphocytic cholangitis
Definition
Chronic disease with lymphocytes and plasma infiltration sorrounding the bile duct and slightly integrated into the epithelium of the bile duct, but not the lumen itself
Most common in cats
Lymphocytic cholangitis
Cause
Suspected to be an immune-mediated mechanism, prednisolone is used, but recovery is rare - so we suspect it is someting more; have found heliobacter in the bile.
Might be bacterial !!
Lymphocytic cholangitis
Clinical signs
Predisposition
- No clinical signs, until the jaundice appears.
- 30% of end stages have ascites, jaundice and hyperglobulinemia
- Mild enlargement of lymph nodes with mild hepatomegaly
Predisposition: Persians
Lymphocytic cholangitis
How to diagnose
- CBC
- Ultrasound
- Histopathology
DO NOT DO FNA !!
CBC for Lymphocytic cholangitis
not characterisitc!
- mild elevation of liver enzymes
- proteinuria
Ultrasound for Lymphocytic cholangitis
very important and informative
- Bile duct is distended, thicker wall . 15x enlarged with narrowing and twisting
- Hepatomegaly
- Choleliths
Prognosis of Lymphocytic cholangitis
very poor !!
The can recover, but survive only 1-3 years
- irreversible changes due to fibrosis
- secondary bacterial infections
- ascites appearance
Differential diagnosis for Lymphocytic cholangitis
- FIP: ascites, icterus, hyperglobulinemia
- EBDO: wide irregular CBD
- Lymphoma: lymphocyte ar periportal area
EBDO = Extrahepatic Bile Duct Obstruction
CBD = common bile duct
