We hear a lot these days about regulating our own cholesterol levels, but did you know that high cholesterol can cause real problems for dogs, too? The two organs most directly affected by high cholesterol are the liver and gallbladder. Ursodiol, a human medication, is finding increasing use these days among veterinarians as an off-label drug to treat high cholesterol and other liver and gallbladder issues in dogs.
“Wait,” I hear you asking, “Do dogs have gallbladders?”
Yes, and they’re just as important to food processing, dog digestion, and filtration as they are in humans. In fact, as susceptible as humans are to high cholesterol, the dog gallbladder is more sensitive and less equipped to handle it naturally. This is one reason why you should avoid, especially around the holidays, feeding your dog fatty, spicy, and sumptuously prepared human table foods. Beyond cholesterol, there are a range of problems and disease afflicting dogs in the liver and gallbladder, and ursodiol is one approach to treatment.
Located in the abdomen, a dog’s liver and gallbladder are not only connected physically, but also functionally. Among other things, the liver produces bile, which is stored and concentrated in the gallbladder. When food leaves a dog’s stomach to continue its journey — being broken down, processed, some converted to energy and the rest excreted as waste — the gallbladder springs into action.
The gallbladder releases bile into the small intestine, where it further breaks down food into components that are either used by the body for energy or eliminated as urine or feces. A dog’s liver and gallbladder are not particularly well-equipped to handle or process cholesterol. Should a blockage, malfunction, or disease arise that affects either organ, the ramifications can be dangerous to the smooth operation of both, and to the well-being of the dog.
Today we’re focusing on the causes and effects of liver and gallbladder disorders in dogs, and medicinal approaches to treatment with ursodiol. As noted above, diet and exercise impact a dog’s digestive health, but high cholesterol is only one result of problems in a dog’s liver and gallbladder. Others include:
Hepatitis means that the liver is inflamed, and chronic means that the problem affects the dog over a long period of time. What causes inflammation of the liver? Chronic hepatitis is one liver disease that has very little to do with diet and exercise. It can be genetic or inherited; Cocker Spaniels, Doberman Pinschers, Standard Poodles, and West Highland White Terriers are popular breeds that seem to be at increased risk. It can be a result of accidentally ingested toxins that react badly when they reach the liver.
Infectious hepatitis, caused by bacteria and passed from dog to dog, can, if untreated, result in chronic hepatitis. Another major cause is autoimmune disease, in which case, the dog’s immune system begins attacking the liver. The worst part about chronic hepatitis in dogs is that, though the liver is a resilient organ, over time, scar tissue begins to build up, which leads to blockages and interruptions in function. Cirrhosis, which we associate with alcohol abuse in humans, is the resulting condition of continual liver inflammation in dogs.
Gallstones are small but painful formations. Composed of bilirubin or cholesterol that lingers in the gallbladder, these stones prevent the normal flow of bile into and out of the gallbladder. They may remain in the dog’s gallbladder itself or become lodged in the bile ducts that bridge the gap between the liver and the small intestine. Causes of gallstones in dogs include excessive cholesterol, gallbladder infection, or bile that is too thick to move fluidly.
Scarring, or cirrhosis in the liver, can, over time, divert the normal course of blood flow to and through a dog’s liver. Sometimes, however, these misdirected vessels are a hereditary issue. These congenital liver shunts cause problems for a dog from the time they are born. Given how important the liver is to processing food and filtering out waste materials, it requires a regular supply of fresh, oxygenated blood. When liver shunts deny or prevent this, toxins can build up in the liver. This can lead to the kinds of inflammation that cause hepatitis and gallstones.
Whether by infection, diet, immune function, or genetics, a dog’s liver and gallbladder can experience any number of interruptions, disorders, and diseases. Making sure our dogs eat a proper, healthy diet and get regular, vigorous exercise are factors that we can control. As we’ve seen, though, sometimes disruptions to normal digestive function are well outside of our control. Ursodiol is a prescription medication that veterinarians are using to address and treat these canine health problems.
So what is ursodiol — also known as urso, or by the brand name of Actigall — how does it work, and can it improve quality of life or provide relief to dogs suffering from gallbladder or liver disorders? First of all, ursodiol is a palatable and pronounceable name for ursodeoxycholic acid, which is itself a naturally occurring component of bile. As a synthetic prescription medication, it is used in treating a growing number of problems linked to the liver and gallbladder.
How does it work? In its natural state, ursodeoxycholic acid’s major function is to regulate the intake, processing, storage, and filtration of cholesterol. As a prescription medication, it is given to dogs with chronic hepatitis. Here, it supplements their compromised liver functioning. For dogs with gallstones that are cholesterol-heavy, ursodiol may help dissolve them. The drug’s facility with cholesterol also makes it a useful medication in treating high cholesterol in dogs.
If you’ve seen a commercial for prescription medications of any sort — the kind that drone on for minutes at a time — you’ll be well aware that no medication is without risks or potential side effects. As one of the golden-tongued announcers might say, ursodiol’s side effects are generally mild. Since it serves a digestive function in dogs, one common side effect is diarrhea as the dog’s body adjusts to its presence.
Some dogs may experience allergic reactions that can actually make their liver problems worse. As with any prescription medication, especially one that is prescribed by veterinarians off-label, follow all directions and dosage guidelines to the letter and report any complications or reactions to your vet. It should go without saying, but if you are taking ursodiol yourself, do not under any circumstances attempt to dose a dog from your own prescription.
About the author: Melvin Peña trained as a scholar and teacher of 18th-century British literature before turning his research and writing skills to puppies and kittens. He enjoys making art, hiking, and concert-going, as well as dazzling crowds with operatic karaoke performances. He has a one-year-old female Bluetick Coonhound mix named Idris, and his online life is conveniently encapsulated here.