Gallbladder disease in dogs and cats
The gallbladder is a small pouch or sac that contains bile produced by the liver. The gallbladder stores bile until it is released into the small intestine, where it helps in the digestion of fat.
In people, the most common disease of the gallbladder is gallstones. In dogs, inflammation of the gallbladder can occur, but the formation of hard stones is uncommon. The gallbladder can also become infected by bacteria, and some cancers can develop in the gallbladder. The most common problem in dogs is a condition called biliary mucocele. This condition is when the bile becomes thickened and is retained in the gallbladder, causing it to be enlarged.
The causes of most gallbladder disease, particularly biliary mucocele, is not well-defined in the dog. Most dogs with gallbladder disease have some sort of underlying metabolic or hormonal problem. Both low thyroid and high cholesterol diseases are associated with an increased risk of developing a biliary mucocele.
Common signs of gallbladder disease include a poor appetite, weight loss, vomiting and diarrhea. The dog may also have jaundice, which is a yellow discoloration of the gums and whites of the eyes. If the gallbladder is ruptured, the dog becomes severely ill because of peritonitis.
Routine laboratory tests are used to assess the state of the liver and the ability for the gallbladder to pass bile into the intestines. The best method of assessing the gallbladder is an abdominal ultrasound. The gallbladder is usually easy to see on ultrasound.
A dog with a biliary mucocele is usually a surgical emergency, because the obstructed gallbladder must be removed before it ruptures. If a mucocele is detected before the dog becomes ill, surgery to remove the gallbladder is recommended. If a gallbladder mucocele is incomplete, drugs may be tried to make the bile more watery and allowed to flow more easily into the small intestine.
Surgery to remove a gallbladder mucocele is relatively risky. If an underlying medical condition can be identified and drugs can dissolve the bile, the prognosis may be better, but it is still guarded, because these dogs can worsen rapidly even with appropriate treatment.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.