An Inquiry into the Cause of Congenital Absence of the Gall Bladder.

Abstract

Out of some 2700 cats examined during the last few years, the writer has noted 3 kittens (2 females and one male) in which no trace of the gall bladder could be found. In one of these there was a large empty fossa vesicae felleae suggesting that perhaps the gall bladder had once occupied it and then been absorbed. In the other 2 there was neither fossa nor any fibrous remainder to indicate that the gall bladder had ever been formed; so that we may assume that it either failed to develop in the embryo or had disappeared before birth. According to Golob, 1 known instances of a congenitally absent gall bladder in man do not exceed 40. In some species of animals, as in the pigeon, a biliary vesicle is formed embryonically but its duct subsequently atrophies, leaving a detached bladder that soon degenerates; in others, as the rat, it is doubtful whether any anlage ever forms (Scammon 2 ). But in rats, according to McMaster, 3 the loss of the biliary reservoir is compensated for by an increased concentration of bile, the bilirubin concentration being 8 times that in the hepatic ducts of the mouse—an animal having a gall bladder. In this connection it is interesting to note that one of the 3 cases of congenital absence of the gall bladder in cats was found in a kitten which was being operated upon. When a sample of the hepatic bile from this animal was examined with a colorimeter it was seen to be 2.2 more concentrated than a sample of hepatic bile from a control kitten, suggesting that if the gall bladder is lost early enough in fetal life, the deficiency is partly overcome by a compensatory mechanism.