Canine Gallbladder Mucocele in Dogs

The gallbladder is an excretory organ that plays an important part in your dog’s digestive health. It stores and fortifies bile, which is required for digestion and to absorb vital nutrients. The formation of a mucocele can cause biliary duct obstruction, bacterial infections, reduced or disrupted bile flow, necrosis of the gallbladder wall, and gallbladder rupture, which can then cause septic peritonitis, or the leakage of fluids into the abdominal cavity. This can cause septic shock, which can be fatal for your dog. Early diagnosis is essential to successful treatment and recovery.

Canine gallbladder mucocele occurs when the gallbladder has become enlarged due to the accumulation of an excessive amount of mucus that has formed into a solid mass, or a mucocele. This is a serious condition that can not only cause pain, anorexia, and collapse, but can even lead to death if left untreated for too long.

While one-quarter of affected dogs are asymptomatic, symptoms of gallbladder mucocele that are present can last for 5 days to several months. These include:

• Lack of appetite
• Vomiting 
• Abdominal pain
• Lethargy
• Jaundice
• Anorexia
• Rapid breathing
• Rapid heart rate
• Diarrhea 
• Fever
• Excessive thirst
• Excessive urination
• Distention of abdomen
• Collapse from septic shock

The main cause of a mucocele formation is excessive accumulation of mucus in the gallbladder. The underlying cause for the formation of a mucocele is unknown, but there are many theories, including:

• Gallbladder disease
• Glucocorticoid therapy
• Progestational therapy
• Gallbladder stones
• Inflammation of the gallbladder
• Biliary sludge
• Cystic mucinous hyperplasia, which causes excessive mucus to secrete into gallbladder
• Mucus-secreting cell dysfunction

Conditions that may predispose your dog to gallbladder mucocele include:

• Small to medium sized dogs
• Middle to older aged dogs
• Shetland Sheepdogs and Cocker Spaniels
• Endocrine disease, such as Cushing’s disease, diabetes mellitus, or hypothyroidism
• High cholesterol
• Fed a high fat diet
• Pancreatitis
• Gallbladder disorder
• Inflammatory bowel disease
• Gallbladder cyst formation

Gallbladder ruptures occur in half of pets with a mucocele before diagnosis is made. This is why it is so important to pay attention to the symptoms of this serious condition. The most common symptoms are abdominal pain, jaundice, fever and abdominal distention. Collapse is a sign of a rupture.

Your veterinarian will perform a physical exam, concurrent with blood work. An ultrasound can detect a mucocele. If biliary sludge is difficult to differentiate from a mucocele, a cholagogue is used with the ultrasound to increase bile flow.

A cholecystocentesis might be performed, wherein an ultrasound guided laparoscopy is used to collect gallbladder bile for testing. The bile is then tested for bacterial infections. A bacteria culture from the gallbladder wall may also be examined. Complications that may arise from this procedure include bile leakage, hemorrhaging, and bacteria entering the bloodstream.

If your dog’s gallbladder has ruptured, and he could be suffering from septic shock, your veterinarian may run tests on abdominal fluids, blood, and cultures. If surgery is being recommended, your veterinarian will run blood counts, a urinalysis, and other tests.

The presence of a mucocele in the gallbladder can lead to further complications, and treatment follows the progression of the complications along two main paths, management and surgery.

Medical Management

Medical management is used in cases where the gallbladder has not yet ruptured or other more serious complications have not yet been diagnosed. Your veterinarian will take the test results and formulate a drug treatment plan. Antibiotic treatment is recommended for 6 to 8 weeks. Choleretic drugs may be prescribed to stimulate bile excretion. Hepatoprotectants may be prescribed to protect the liver, such as silymarin (milk thistle) and SAMe. Dogs are re-checked for mucoceles after 4 to 6 weeks of treatments. Surgery is generally recommended for dogs who do not improve with therapy, or if a re-examination found progressing symptoms.

Surgery

Emergency surgery should be performed if the gallbladder has ruptured, or if septic peritonitis is present. Surgery is also recommended if there is a suspected biliary duct obstruction, to explore the abdominal cavity, and to perform a cholecystectomy, a surgical removal of the gallbladder. Removal of the gallbladder will prevent rupture and any secondary infection in the gallbladder.

Other procedures may be undertaken once problems inside the abdominal cavity have been identified. Surgery will also flush the cavity clean if rupture has occurred, and enable collection of  any other samples needed for further diagnosis.

Your dog will be stabilized with fluids, antibiotics, antiemetics and pain medications before anesthesia is given for surgery. Your dog may also be given electrolyte therapy that will start before surgery and continue after, until bile flow returns to normal, generally in 2 to 4 days.

Complications of a cholecystectomy can include vomiting, bile peritonitis, pancreatitis, and death. While 22% to 40% of dogs die within 14 days after surgery, the rate of survival is excellent if the dog survives this period. After surgery, it may take 1 to 3 days for your dog to stabilize.

If your veterinarian has recommended medical management, then you may need to administer the antibiotics, choleretics, and hepatoprotectants at home. A veterinary visit to check on the treatment success will be needed in 4 to 6 weeks after treatment began. Subsequent visits may be scheduled.

Home treatment of your dog after surgery will include antibiotics specific to any infections found, and hepatoprotectant drugs to prevent liver damage. Also, the switch to a low fat diet may be recommended. If your dog has survived past the initial 14 days after surgery when most complications arise, then the rate of survival is excellent.