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When the cat’s liver fails there are four conditions that we look to as the most common causes:
The most common of the above are Hepatic lipidosis, which occurs when a cat, particularly an overweight one, goes for a long period without eating. (Clearly, any
condition that causes a cat to lose his appetite could cause hepatic lipidosis as a serious complication.) The next most common cause of feline liver failure is
“cholangiohepatitis,” which amounts to a bacterial infection and prognosis is generally fair. The other two common causes carry a much poorer outlook so obviously it is
important to distinguish them and this can only be done with some sort of tissue sampling of the liver, ideally a biopsy.
We will assume that you have already had this procedure done, that you already know your cat has cholangiohepatitis, and that you are looking for more information.
What is “cholangiohepatitis?”
The word cholangiohepatitis breaks down into “chol” (bile), “angio” (vessel), hepat (liver) and “it is”(inflammation). Putting this all together means inflammation of the liver and bile ducts.
You have probably heard of bile ducts but may not really be sure what bile is all about. Bile is a greenish material the liver makes, transports to the gall bladder via small bile
ducts. The gall bladder is a small greenish sac about the size of a superball where bile is stored. When the appropriate hormonal signals are present, the gall bladder contracts
and squirts bile into the small intestine via one very large duct called the “common bile duct.”
Bile has several functions. It emulsifies the fat in our diets so that we can absorb it into our bodies. It also serves as a medium to dump toxins that the liver has removed from
our bodies and processed so they cannot be reabsorbed.
This is a fine system but problems can occur when the bacteria that live in the small intestine venture up the bile duct and invade the liver, which is normally sterile (free of
bacteria). Inflammation results and the liver can fail.
What is the connection with Inflammatory Bowel Disease and Pancreatitis?
In one study, 80% of cats with cholangiohepatitis also had Inflammatory Bowel Disease and 50% also had Pancreatitis. Feline anatomy is a little different from that in other
species. In the cat, the pancreatic duct, which delivers digestive enzymes to the intestine, opens into the same “pore” as the common bile duct. Both ducts share a
“doorway” to the intestine. This means that if bacteria invade the doorway, both the liver and pancreas are at risk for infection.
Inflammatory Bowel Disease involves infiltration of the intestinal lining with cells of inflammation. Absorption of nutrients becomes altered which in turn alters the
populations of bacterial living in the intestine. An overgrowth of bacteria can occur or more aggressive species of bacteria can take over the area. It is easy to see how the bile duct can become invaded.
Treatment
The cat in liver failure will require hospitalization, fluid therapy, and some kind of nutritional support (force-feeding, syringe feeding of a liquid diet or whatever is
necessary) regardless of the cause of the liver disease.
Antibiotics
Antibiotics are helpful in any liver failure case as they help reduce the intestinal bacterial populations (any noxious substances they produce are normally
detoxified by the healthy liver but a sick liver will not be so efficient). Antibiotics also clear the liver of invading bacteria, which is what cholangiohepatitis is all
about. Expect the cat to require 3-6 months of antibiotics after recovery.
Choleretics
A choleretic is a medication that makes bile more liquid so that it can flow smoothly without sludging. Flow of bile in the proper direction helps remove
not only the toxins the liver is trying to remove in bile but also helps prevent bacteria from “swimming upstream” towards the liver tissue. The chief choleretic prescribed for animals is Ursodiol. A cat may well be on this medication for life after an episode of cholangiohepatitis.
SAMe
This nutritional medicine has gained tremendous popularity in therapy for all liver diseases and should probably not be left out here. SAMe stands for S-adenosylmethionine. It has several desirable functions but mostly it is an
antioxidant, protecting the sick liver cells from the toxins they have absorbed and normally would be excreting in bile.
Silymarin
This is the active ingredient in the herbal medication commonly known as “milk thistle.” It has been shown to be protective to the liver in Amanita mushroom
poisoning and many have extrapolated that it should be protective to the liver in other toxic scenarios. It be prescribed for cats with cholangiohepatitis.
Immune Suppression
This may seen intuitively inappropriate for a condition that involves a bacterial infection, but some patients simply cannot get better until their immune system
is suppressed. Why is this? For many cats, the problem started with Inflammatory Bowel Disease: infiltration of the intestinal lining with inflammatory
cells. Immune suppression is the cornerstone of therapy for this condition. Once the immune reaction is suppressed, the lining of the GI tract regains normal
thickness and function, the bacterial bloom subsides, the invasion of the liver and pancreas ceases. In some cases, immune suppression is simply needed to
relieve the inflammation inherent to cholangiohepatitis. Typical medications include prednisone (or prednisolone depending on how severe the liver failure
is). More aggressively, chlorambucil, a chemotherapy drug, is used.
Overall, cholangiohepatitis is one of the more treatable liver conditions of the cat. This does not mean that every cat will recover; some cats are quite advanced by the time
they are first seen by the veterinarian. Pancreatitis can represent a lethal complication, depending on severity. The cat that survives the acute episode can expect long term
medication administration and the possibility of relapse or flare-up. The owner should become familiar with Inflammatory Bowel Disease and Pancreatitis as well.
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