Liver disease in cats is among the most common problems affecting cats' internal organs, and every pet parent should be aware of how these issues can affect their four-legged friend. Learn how cat parents can intervene in time to improve cats' quality of life or, with a veterinarian's help, potentially cut off the disease outright.

The Role of the Liver

Your cat's liver (and yours) is nestled between the lungs and the stomach. It's a complex organ that is a component of several major body systems. These are its major functions:

• It helps break down nutrients coming in through the digestive system.
• It detoxifies the body by breaking down incoming toxins carried by the blood.
• It makes useful proteins that aid in blood clotting.
• It stores essential nutrients like vitamins, minerals, sugars and fats.
• It serves an immune system function by capturing invaders and neutralizing them.
• It plays a metabolic role by helping regulate blood sugar (glucose).

It may seem counter-intuitive, but not all liver disease in cats originates in the liver. Sometimes it's a faraway infection or cancer that can lead to feline liver diseases. Those that start in the liver are termed primary while those that originate elsewhere are considered secondary. Hepatitis (hepatic is the term for any condition having to do with the liver, and -itis means inflammation) is the name for any swelling of the liver. In cats, its causes are many and varied.

What Causes Liver Disease in Cats?

Liver problems can have a range of causes. Some issues can be prevented by taking certain steps to keep your cat healthy, but others can appear with little warning.

If a cat eats certain toxins, like acetaminophen (i.e., Tylenol), plants, household chemicals and prescription drugs (among others), it may lead to a liver condition called toxic hepatopathy. Hunting critters that find their way into your house can also cause problems. In places where lizards roam (like South Florida or Central and South America), cats who like a little reptilian snack now and then can get a parasite called a liver fluke that lodges and grows in the liver. These can lead to inflammation, bacterial infections, abscesses and other disruptions of the liver's function. The parasitic infection of toxoplasmosis can also cause liver problems, Cornell University College of Veterinary Medicine notes.

Hepatic lipidosis or "fatty liver disease," is perhaps the most well-known among liver diseases in cats. According to the Cornell Feline Health Center, it happens when a cat suddenly stops eating and the body sends signals to start using the fat stored throughout the body. If this happens quickly and the cat is overweight or obese, fat can flood the bloodstream and settle in the liver, hindering its normal functions. This is yet another reason why helping your fur baby maintain a healthy weight is critical.

Cholangitis is an often idiopathic (unexplained) inflammation of the bile ducts (or gallbladder). When it involves the liver tissue itself, vets call it cholangiohepatitis, notes the Cornell Feline Health Center. The causes are often related to viruses or bacteria, but in cats, a sensitivity of the liver can predispose it to inflammation. Why some feline livers are prone to swelling is often as mysterious as our cats themselves. Another puzzling condition is triaditis, which is marked by a "triad" of inflammation in the liver, intestines and pancreas.

Cancer can also adversely affect a cat's liver. Thankfully, primary liver cancers aren't common, comprising about 2 percent of all feline cancers. The most common of these is bile duct carcinoma. The more common cancers of the liver are secondary to other cancers (referred to as metastatic), are spread from other parts of the body. Lymphoma, a blood cancer, is perhaps foremost among these, but cancers of the spleen, pancreas or intestinal tract can also spread to the liver.