Downeast Dog News


By Gail Mason, DVM, MA, DACVIM | Dec 01, 2019

Did you know that dogs have gallbladders just like we do? The gallbladder is a hollow organ that is tucked up against and is connected to the liver. It stores bile, a yellowish-green substance which is essential in the proper digestion of food (pet owners may unfortunately recognize this color on their carpets!) The liver transports bile through the main bile duct into the gallbladder and small intestines. Inflammation of the gallbladder can be associated with the formation of “gallstones,” as it does in humans, but it is much less common in dogs. In certain instances, gallstones can incite inflammation of the lining of the gallbladder (“cholecystitis’) and/or result in an obstruction of the bile duct. A bile duct that is completely blocked can begin to leak bile into the abdomen (“bile peritonitis”). This latter event is not very common but does warrant immediate surgical and medical intervention.

The gallbladder generally “goes about its job” with little notice or fanfare. However, for a small organ, it can have a “big influence” on the body if it is malfunctioning. The causes of “cholecystitis” include: 1) malfunction of muscle contraction of the gallbladder walls (reducing bile flow into the intestines); 2) bacterial infection of the gallbladder and biliary system (“cholangitis”); 3) obstruction by gallstones or liver/pancreatic/intestinal tumors; 4) trauma (such as being hit by a motor vehicle); and 5) pancreatitis (the bile duct traverses the pancreas, and can be blocked by pancreatic inflammation and swelling).

What is a mucocele?

Normal bile contains less than 3% “mucus” as part of its watery, secretory product. In dogs with delayed gallbladder emptying, the bile product contains too much mucus and the bile is thick and “goopy.” The result is a distended gallbladder with an inflamed lining. The risks of developing a mucocele are increased in dogs with underlying illnesses such as diabetes mellitus, hypothyroidism, pancreatitis, and Cushing’s disease (a common disease of the adrenal glands). A mucocele can be diagnosed quickly by an abdominal ultrasound. It has an image pattern that looks like the cut surface of a kiwi fruit. The so-called “kiwi” sign belies the seriousness of this finding. Once formed, a mucocele cannot be dissolved. If it is large enough to stretch the walls of the gallbladder, it can result in rupture of the organ, requiring emergency surgery.

How do I know if my dog has gallbladder disease?

As an isolated diagnosis, there is no way for you to “tell” if your pup has such a problem. The symptoms of this disease are variable, but include loss of appetite, lethargy, vomiting, fever, diarrhea, and abdominal pain. About half of dogs that have severe or acute gallbladder disease will have “icterus” or “jaundice,” which is yellowing of the gums, whites of the eyes, and skin. The urine will often be notably dark yellow/green. While these are nonspecific signs of illness, they are ones that should prompt evaluation by a veterinarian.

How is the diagnosis made?

Your veterinarian will likely start by giving your dog a thorough physical examination and recommend blood tests such as a complete blood count (CBC), and chemistries (body function tests). Findings that point to a potential gallbladder issue include abdominal discomfort, an increased white blood cell count (from inflammation/infection), increase in liver enzymes, and especially “bilirubin.” Bilirubin is a main component of bile and increases when there is a disturbance within the gallbladder, bile ducts, or liver. Abdominal radiographs (x-rays) may be helpful but not usually diagnostic for gallbladder disorders. Fortunately, ultrasound is noninvasive, usually requires no sedation, and can readily assess the liver, gallbladder, and pancreas. It is quite sensitive in the detection of rupture or impending rupture of the gallbladder.

What treatments are available for gallbladder disease?

Luckily, most dogs with gallbladder disease do not require surgical intervention. Instead, they can be successfully managed medically. Infections are usually treated with combination antibiotics, as the specific organism (s) responsible for the infection is not easily identified (without surgery). A drug called ursodiol is frequently prescribed for gallbladder disease. It increases the “watery secretions” of bile, thus facilitating its flow out of the gallbladder (except in cases of obstruction). It also reduces the toxicity of bile accumulation within the gallbladder and liver. Patients can benefit from a low-fat diet and control of underlying diseases that may exacerbate gallbladder disease. Periodic veterinary examinations, blood tests (+/- ultrasounds) all improve long term control of hepatobiliary disease. In the uncommon event of a mucocele, surgical removal (“cholecystectomy”) of the gallbladder by an experienced surgeon (preferably a specialist) is of paramount importance. A “wait and see” approach could result in dire consequences. Consider at least annual screening health exams and blood work for your adult and older dogs to identify emerging health conditions early!!