Gallstones in dogs are made of calcium and other secretions that form in the gallbladder. This medical condition is called cholelithiasis. The gallbladder is a balloon-shaped structure found near the liver. Gallstones can be present without causing health issues, but gallstones that migrate from the gallbladder into the biliary tract, a series of ducts from the liver to the gallbladder to the intestine, may block the normal flow of bile.
Some dogs have gallstones with no apparent symptoms. If there is blockage of bile ducts or infection related to gallstones, however, a dog may suffer from abdominal pain, fever, vomiting and, in advanced cases, jaundice. Lack of appetite may also occur in a dog suffering from gallstones. To diagnose cholelithiasis, a veterinarian will look for liver disease, pancreatitis and inflammation or distention of the bile duct or gallbladder. A comprehensive blood count will look for bacterial infection, bile duct obstruction or other underlying conditions. X-rays are generally not useful in analyzing gallbladder disease, but an ultrasound can help a veterinarian find internal abnormalities.
Gallbladder disease is broken into three types: obstructions, non-obstructive diseases and ruptures of the gallbladder or biliary ducts. The gallbladder is located between lobes of a dog's liver. Bile made in the liver drains through ducts into the gallbladder. Bile is stored and concentrated in the gallbladder. Bile helps a dog's body digest fats when it is released into the small intestine through the biliary duct. Gallstones in dogs are different from gallstones in humans, mainly because the bile in dogs has a very low cholesterol saturation, much unlike human bile. In dogs, gallstones have low cholesterol and calcium composition.
Gallstones in dogs can be caused by low protein intake. They may also be caused by genetic predisposition. Gallstones sometimes form because of infection, a tumor or the shedding of cells. If a dog's gallbladder is functioning poorly, it may interrupt normal bile flow, or the bile may be oversaturated with calcium or cholesterol, resulting in gallstones.
A well-balanced diet, with healthy ratios of fat and protein, is the best prevention of dog gallstones.
Surgery generally is not recommended for gallstones in dogs. Serious symptoms, like fever, infection and abdominal pain, warrant treatment by a veterinarian. If a dog is not in immediate health danger, medically dissolving gallstones is an option. This is done in a veterinarian hospital or clinic with an intravenous drip. Jaundice, liver enzyme imbalance and related medical issues will be treated at the same time. Your vet may prescribe antibiotics if infection is present. When a dog presents with critical symptoms, your vet will order an ultrasound, perhaps followed by exploratory surgery. Gallbladder stones in dogs may become a chronic problem. New stones often form even if surgery removes existing gallstones.
Dogs that experience gallstones may be prescribed an ongoing restricted-fat, high-protein diet. Specially formulated dog food is often available through a veterinarian. Prescription diets can be expensive; dog food recipes that an owner can make are often an excellent alternative. The prescription medication Ursodiol (a naturally occurring bile acid) is sometimes indicated for treatment of gallstones containing cholesterol.
Gallstones are different from bladder stones and kidney stones. The causes and treatments of the three are different. Poodles, miniature Schnauzers and Shetland sheepdogs seem to be genetically predisposed to gallstones.