“Tucker” is a 12 year old M/N Collie that presented for a 3 day history of vomiting and inappetance. Physical examination revealed 5-7 % dehydration and icteric sclera and gums. Abdominal palpation was unremarkable and he was not overtly painful on palpation. CBC showed mild anemia (HCT 32%) and neutrophilia (neutrophils 24,000). Chemistry profile showed marked elevation of liver enzymes (ALP 4136 U/L, ALT 935 U/L, GGT 54 U/L) and elevation of total bilirubin (4.7 mg/dl). A complete diagnostic abdominal ultrasound was requested and the following images were obtained.
In these images, you can see findings consistent with a mature gallbladder mucocele including the classic stellate or “kiwi fruit” appearance. Based on Tucker’s clinical profile and these ultrasound images, do you think that the gallbladder mucocele has ruptured? Would you recommend surgery right away? What would be the basis for your recommendation?
Look at these images more closely. There is a very small rim of free fluid suggestive of peritonitis; and the wall of the gallbladder appears slightly retracted in this area.
On the basis of this more subtle finding suggestive of gallbladder rupture and peritonitis, as well as the presence of elevation of total bilirubin, a ruptured gallbladder mucocele was suspected and thus emergent surgical intervention was recommended.
It is important to remember that ruptured gallbladder mucoceles often create a very local peritonitis so obvious bile peritonitis is not always detected by ultrasound. Other than the very scant fluid noted adjacent to Tucker’s gallbladder, no other free fluid was noted. However, an abdominal FAST (AFAST) exam was performed in addition to the complete diagnostic abdominal ultrasound in order to more completely search for free fluid. Moreover, by using AFAST and its abdominal fluid scoring system, free fluid volume may be semi-quantitated by recording Tucker’s abdominal fluid score (AFS). I have found that it is often more difficult to appreciate small quantities of free fluid when dog’s are in dorsal recumbency than when performing AFAST in right lateral recumbency and applying the AFS. In summary, Tucker’s significant elevation of liver enzymes and total bilirubin in conjunction with the ultrasound finding of a mature gallbladder mucocele with free fluid, should increase suspicion for gallbladder rupture which warrants surgical exploratory laparotomy.
Gallbladder mucoceles are a relatively common finding in dogs. Gallbladder mucoceles are over-represented in certain breeds including Shetland Sheepdogs and Cocker Spaniels and have also been reported in association with hyperadrenocorticism. Not uncommonly, gallbladder mucocels are found as an incidental or unexpected finding in older dogs. In any event, when recognized using ultrasound, gallbladder mucoceles warrant further evaluation including complete blood count with differential, and serum chemistries including liver enzymes and total bilirubin.
Gallbladder mucoceles may also be recognized using the Focused or COAST (Cageside Organ Assessment with Sonography) exam of the gallbladder. It is important to recognize that the presence of a gallbladder mucocele warrants further evaluation by a trained ultrasonographer, and generally, surgical therapy. Mature gallbladder mucoceles have a distinct ultrasound profile as a stellate or “kiwi fruit” appearance caused by fracture lines between intraluminal mucous collections. When immature, there are variable degrees of non-mobile sludge seen between the focal collections of mucous; and variabilities within the gallbladder wall, which may be thickened, irregular, and/or hypoechoic or hyperechoic.
Medical therapy of gallbladder mucoceles has been reported and generally involves feeding a low fat diet in conjunction with ursodiol administration. I have used medical therapy in dogs that do not have clinical signs or concurrent elevation of liver enzymes and total bilirubin and also monitor these dogs closely with minimally Focused or COAST gallbladder ultrasound exams and AFAST along with serum liver enzyme and total bilirubin evaluation every 1-3 months. However, if and when clinical signs are apparent and/or there is significant liver enzyme and total bilirubin elevation, surgical management is best recommended as there is a significant risk of gallbladder rupture in these patients.
Stephanie Lisciandro, DVM
Diplomate ACVIM (Small Animal Internal Medicine)