The diagnosis of gallbladder disease is initiated by the veterinarian's suspicion that gallbladder disease might be present
as based on the case history and physical examination and laboratory findings. Radiographic and/or ultrasonographic imaging,
serum bile acid determinations, fine needle aspiration of gallbladder for cytology and culture, and possibly liver biopsy
for histopathologic examination may follow the initial results.
The CBC may show mild to moderate nonregenerative anemia, neutrophilic leukocytosis with a left shift, thrombocytopenia, or
other morphologic changes. Increased serum liver enzyme activities such as increased serum ALT and AST are reliable indicators
of hepatocellular damage or cholestasis. Serum ALP and GGT activities increase in cholestasis. In cats, any increase in serum
ALP activity indicates cholestasis. Hyperbilirubinemia may occur with active hepatocellular damage and also occur with cholestasis
secondary to extrahepatic disease. Any degree of bilirubinuria in cats of any age is abnormal and suggestive of active liver
The most practical method of assessing liver and/or gallbladder dysfunction in nonicteric dog or cat is serum bile acid determinations.
Fasting and two-hour postprandial bile acid concentrations has the same normal range values irrespective of age and will be
increased with primary or cholestatic liver and/or gallbladder disease.
Survey abdominal radiography and ultrasonography may be helpful in diagnosing gallbladder diseases, identifies distinct liver/gallbladder
masses, mineralization and cholelithiasis.
Ultrasound-guided fine needle aspiration of the gallbladder for cytology is relatively safe procedure for diagnosing some
gallbladder diseases. Gallbladder aspirates may be obtained from a nonsedated animal placed in either dorsal or right lateral
recumbency. The abdomen is clipped and prepared as for ultrasonography, and a 1-inch or 1.5-inch, 22-gauge needle is advanced
into the gallbladder under guidance of the ultrasound beam.
A single gentle aspiration with a 6-ml syringe will usually yield adequate numbers of cells for cytologic evaluation and for
bacterial culture. Smears of the gallbladder aspirate are then made, and the slides are stained with a cytologic stain such
as Wright's-Giemsa. Exploratory laparotomy and surgical biopsy can also be performed, with the advantage of being able to
visualize the liver lobes, gallbladder and extrahepatic biliary system.
Cholecystitis and cholelithiasis are considered by many people to be uncommon in dogs and cats - a frequently quoted statement
by many veterinarians and veterinary textbooks that is incorrect. Because of routine use of abdominal ultrasonography, many
dogs and cats are now being diagnosed with acute and chronic gallbladder diseases. Cholecystitis often leads to vague signs
of vomiting, fever and abdominal pain. The usual cause of cholecystitis is thought to be a bacterial infection from ascending
bacteria from gastrointestinal tract or from hematogenous bacteria. When cholecystitis becomes severe, gallbladder necrosis
and rupture may occur, with subsequent biliary peritonitis.
Ultrasonography identifies increased gallbladder wall thickness and echogenicity; dilated, tortuous bile ducts and concurrent
cholelithiasis. Antimicrobial therapy based on bacterial culture and sensitivity test results is the optimal treatment for
cholecystitis. Severe cases of cholecystitis, such as emphysematous or necrotic cholecystitis, may be treated surgically with
Choleliths occur in older dogs and cats as well. Choleliths are usually composed of cholesterol, bile acids, pigments, calcium
and protein. Diet and cholecystitis are predisposing causes for cholelith formation. The clinical signs and diagnostic approach
to cholelithiasis are similar to that used for cholecystitis.
Treatment of cholelithiasis may be either surgical or medical. Cholecystectomy can be performed for cholelithiasis, which
will prevent recurrence. Medical therapy may include antimicrobial agents and commercial canine diet formulated for liver
disease. Extrahepatic bile duct obstruction can occur in older cats, usually secondary to cholelithiasis, inspissated bile
or parasitic infection. Choleliths in cats contain cholesterol, bilirubin derivatives and calcium. Occasionally, bile sludging
secondary to increased mucosal uptake of bile fluid can result in overt inspissation of bile with biliary obstruction. Biliary
obstruction and choleliths result in anorexia, vomiting, fever, icterus and acholic (depigmented) stools in severely affected
Cats of any age may be affected with a fluke infection of the biliary tract or pancreas. Signs associated with a fluke infection
are similar to other causes of biliary obstruction. Diagnosis of flukes is made by routine fecal sedimentation or use of formalin-ether
sedimentation techniques to identify the typical-appearing fluke eggs. Occasionally, fluke eggs may be detected in abdominal
fluid or liver cysts.
Optimal treatment for liver and pancreatic flukes is praziquantel (20 to 30 mg/kg single time or daily for three days). Parasitized
cats with severe liver disease secondary to biliary tract obstruction may have a guarded prognosis.