The spontaneous amorphous black pigment gallstone of the domestic dog

Canine extrahepatic biliary disease

“…There is a similar distribution of single versus multiple choleliths in dogs (Ward et al 2020). The prevalence of cholelithiasis in dogs is low and estimated to be between 0.97 and 13% (Wales et al 1982, Ward et al 2020. Dogs with cholecystoliths and extrahepatic choleliths tend to be older aged (>9 years), but can occur in young dogs (Lee et al 2017a, Ward et al 2020.…”

“…Investigators in one study reported that 87% (53/61) of dogs were subclinical at the time of cholelith identification (Ward et al 2020). The presence and severity of clinical signs are typically related to complications that can manifest as a result of cholelithiasis, which in dogs, includes partial or complete EHBDO, gall bladder rupture, sterile or septic bile peritonitis, all subtypes of cholecystitis (see above; cholecystitis section), emphysematous cholecystitis, cholangitis/cholangiohepatitis and cholecystocutaneous fistula (Wales et al 1982, Church & Matthiesen 1988, Bromel et al 1998a, Mehler et al 2004, Baker et al 2011, Fabbi et al 2014, Lawrence et al 2015, Tamborini et al 2016, Folk & Lux 2019, Ward et al 2020. In humans, less severe clinical signs of cholelithiasis could include episodic abdominal pain known as "biliary colic".…”

“…Investigators from one study reported that dogs with naturally occurring black‐pigment stones had significantly greater accumulation of mucus and magnitude of gall bladder inflammation than dogs without choleliths (Wales et al . 1982). Unfortunately, these results do not demonstrate a clear cause‐effect association, but at least suggest a possible overlap in black‐pigment stone pathogenesis with humans.…”

Decreased Gallbladder Emptying in Dogs With Biliary Sludge or Gallbladder Mucocele

“…This is supported by in vitro studies on murine and canine gallbladder epithelial cells; 6,7 where hydrophobic bile acids had cytotoxic effects. Although cholelithiasis is uncommon in dogs compared to humans, [8][9][10][11][12] incidence of gallbladder mucocele in dogs has been reported increasingly over the past decade. [13][14][15][16] Gallbladder mucocele is an abnormal accumulation of mucin accompanied by hyperplasia of mucus-secreting epithelium.…”

“…This is supported by in vitro studies on murine and canine gallbladder epithelial cells; where hydrophobic bile acids had cytotoxic effects. Although cholelithiasis is uncommon in dogs compared to humans, incidence of gallbladder mucocele in dogs has been reported increasingly over the past decade …”