Cholecystitis can have acute or chronic presentations. Anorexia, vomiting, abdominal pain, and fever are typical signs of acute cholecystitis.25,26 Patients with chronic cholecystitis may have milder signs of chronic intermittent vomiting, anorexia, weight loss, and/or abdominal pain or no clinical signs at all. Cholecystitis may be present alone or in combination with cholangiohepatitis, which is typically characterized by chronic neutrophilic inflammation.4,5 Abdominal radiography can aid in the diagnosis of cholecystitis, particularly if emphysematous cholecystitis is present with a gas-filled gallbladder or gas opacities in the pericholecystic region. Nonspecific radiographic findings may reveal a right quadrant abdominal mass effect, poor serosal detail, and/or choleliths.9,27 The following abdominal ultrasonographic findings can be suggestive of cholecystitis and/or cholangiohepatitis: thickened, hyperechoic, irregular and/or laminar gallbladder wall; echogenic intraluminal contents; pericholecystic fluid or echogenic abdominal effusion; distended bile duct; and/or heterogeneous or hyperechoic hepatic parenchyma.4,9 Bile samples can be obtained with percutaneous ultrasound-guided cholecystocentesis to assess for inflammation, infectious agents, and culture and susceptibility. Culture and susceptibility testing is particularly important, as resistance can occur with empiric broad-spectrum antimicrobials.5 Common bacterial isolates include Escherichia coli, Enterococcus spp, Klebsiella spp, Clostridium spp, and Bacteroides spp.4,5,25,28
Treatment of cholecystitis includes medical management, but surgical intervention may be necessary depending on the severity of signs and gallbladder rupture. Cholecystectomy can reduce morbidity and mortality in dogs with cholangiohepatitis and/or cholecystitis.4 Medical therapy includes antimicrobial administration guided by either culture and susceptibility results or, when culture and susceptibility results are unavailable, empiric treatment against common isolates (eg, amoxicillin/clavulanic acid and enrofloxacin). Additional treatment options include ursodiol and supportive care.9,25 Cholecystectomy is typically the surgical treatment of choice when surgery is required and in cases in which only the gallbladder is affected.9,29