Is your cat lethargic or vomiting? What if she seems to have a yellow cast to her eyes? If you suspect her liver is affected, how do you determine the exact problem?
What is liver disease in cats? How do you know your cat may have it, and what are indications that it may be serious?
Liver disease presents as vague signs in felines because it performs so many tasks for the body.
Its failure leads to a shutdown in the manufacture and processing of numerous amino acids, hormones, and metabolic compounds. The liver’s effect on surrounding vital organs makes reading your cat’s symptoms even more complex.
We will cover liver disease in cats, diagnostic tests, and specific diseases. You will know what to look for, understand why your veterinarian performs certain tests, and learn some risk factors for feline liver disease.
How does the liver function normally in cats?
As the liver has over 500 functions to perform, it is easy to see how a cat with any disease in this major organ can suffer dire consequences. Liver failure usually results from a breakdown in one of its major mechanisms.
- Metabolism – Helps break down fats into useable energy by producing bile for example
- Regulation of blood sugar
- Manufacture of lipoproteins to carry fats, other proteins, cholesterol, and clotting factors
- Breakdown of ammonia
- Detoxification – Breaks down medications and toxins
- Filtration – Bacteria, waste products in blood
- Storage – Iron
- Manufacture of certain hormones
What are the signs of liver disease in cats?
Unfortunately, the signs of liver disease in cats are frequently vague and nonspecific. Not only can symptoms of liver problems mimic many other diseases, but cats are adept at hiding their illness.
By the time owners realize something is wrong with their cats and seek medical help, the disease is often advanced.
- Lethargy – Less energy than usual, no interest in normal activities
- Anorexia or decreased appetite
- Jaundice – Yellow tint to skin and whites of the eye; Can be obvious or very subtle
- Weight loss – Can be sudden or gradual
- Drinking and urinating more than usual
- Changes in the skin – Loses integrity or changes texture; can indicate advanced liver disease
- Drooling – May indicate nausea
- Behavioral changes
- Ascites – Free fluid in the abdomen
Your veterinarian uses many tools to diagnose liver disease.
Your veterinarian will use the background of your cat and the history of symptoms you give to either put liver disease on her or his list of suspects or to rule it out.
If medical professionals then determine that liver disease is a viable possibility, they will perform a physical examination and then further diagnostic tests.
Signalment refers to information about your cat that may make the possibility of certain disorders or other characteristics more or less likely. For example, cancer is more likely in an older cat than a kitten.
The features of signalment are as follows.
- Altered status – Is the cat spayed or neutered?
- Indoor or outdoor cat
History is any information that you can give your veterinarian about your cat’s current condition that may be helpful.
- Duration of symptoms
- Specific nature of signs
- Any history of similar signs
- The previous history of the related disease – Example would be recurring pancreatitis and now your cat has signs of diabetes
- Current diet
- Medications and holistic treatments
- Possible exposure to toxins
A lot of information can be gleaned from a thorough physical exam. Your veterinarian may detect weight loss that you were unaware of.
An exam should pick up on any discernible color change (subtle jaundice, or paleness), hydration level, and joint crepitus (crackling that may indicate arthritis).
Your pet’s doctor will also palpate her abdomen to check for free fluid, the shape and size of organs such as the kidneys, edges of the liver, and intestines, and pain.
Auscultation of the heart with a stethoscope will check for murmurs or abnormal rhythms. A heart rate that is too fast can indicate dehydration, pain, or an overactive thyroid gland.
Blood Chemistry and Urinalysis
Initial screening tests to check the overall health of your cat’s organs usually involve a blood chemistry profile and an analysis of a urine sample.
A urinalysis tells your veterinarian about your cat’s hydration status and the presence of abnormal substances such as blood cells, casts (shed with kidney damage, proteins, glucose, or bilirubin (liver disease).
A basic blood test measures liver and kidney enzymes, a complete blood count (red and white blood cells), electrolytes, baseline T4 (thyroid hormone significant in cats), and proteins.
Some of the enzymes on typical blood chemistries that can indicate liver problems are below.
- AST and ALT – Aspartate and alanine aminotransferase, respectively; These enzymes are a couple of the most common levels used to assess liver function; AlT is very specific for the liver, but AST can also indicate problems with the heart or skeletal muscles
- ALK or ALKP – Alkaline phosphatase blood levels increase with liver, gallbladder, or even pancreatic disease; Also, ALKP levels will be exceedingly high with the presence of bone growth in kittens, further evidence of the importance of signalment
- Albumin – A protein that rises with dehydration most commonly but also with diseases of the liver, kidneys, and intestines; It will decrease with hemorrhage
- BUN – Blood urea nitrogen, often used in conjunction with creatinine levels to assess kidney disease, can also be elevated with liver disease
- Bilirubin – Can indicate bile duct disease, but also rises with hemolytic anemia (blood loss from the destruction of red blood cells)
Additional tests may include SNAP kits for infectious diseases like feline infectious peritonitis or feline leukemia and hormonal assays like a full thyroid panel.
While radiographs give a medical professional a good overall impression of the intestines and kidneys, they can be limited regarding assessing the liver.
It is possible to determine if the liver is larger than normal on a radiograph. According to NCBI, radiographic evaluations of liver length to the length of thoracic vertebrae from T1 to T11 approach the accuracy of measurements on CT scans.
Many veterinarians evaluate liver function with ultrasound whereby they can also perform biopsies.
A liver ultrasound is especially helpful to diagnose tumors and hepatic lipidosis, a life-threatening condition. Specialists may use CT scans or MRIs, but these can be cost-prohibitive.
A biopsy is the best way to get a specific diagnosis of liver disease in a cat. It involves removing an exceedingly small tissue sample and having a laboratory analyze the cells.
The disadvantages of a liver biopsy are bleeding and invasiveness. Ultrasound-guided or laparoscopic biopsies are less invasive, usually only involving a small port or incision.
Sometimes your veterinarian will perform a liver biopsy during exploratory abdominal surgery.
Specialists can obtain biopsy results within minutes to hours, but your local veterinarian will likely have to send samples to a laboratory. Such cases may take days to render results.
What are some common causes of liver disease in cats?
The reasons cats can have so many vague signs of liver disease are that numerous possible causes exist.
Toxins and bacterial infections impact the liver directly and obviously. However, the history can be blurry if you are unaware of any potential exposure.
Cholangiohepatitis is a term that encompasses the fact that the pancreas, small intestine, gallbladder, and liver are in sync. If one organ develops inflammation, the others can become similarly affected.
Triaditis is when the liver, small intestine, and pancreas suffer inflammation concurrently.
An inflamed pancreas or small bowel can cause liver inflammation. Likewise, hepatitis can lead to intestinal upset or pancreatitis.
Other causes of liver damage, inflammation, or disease are viral infections, metabolic disorders such as diabetes, cancer, and medications.
There are several common liver diseases in cats
While there are a few rare and fascinating liver disorders in cats, the more prevalent ones are what will concern you most.
Cancer can either originate as a solitary tumor on the liver or metastasize from elsewhere in the body. Somewhere in between these two scenarios are blood-borne cancers like lymphoma where the liver possesses lymphatic components.
Primary liver cancer in felines is rare but typically involves a carcinoma of the outer hepatic cells or, more commonly, the bile duct.
Metastasis frequently occurs as a spattering of spots. Liver cancer is more prevalent in older cats than those under the age of six years. Treatment can include surgery or chemotherapy. Lymphoma is particularly responsive to chemo.
Also called fatty liver disease, hepatic lipidosis is a common and serious disease unique to cats. Whether a cat is overweight or not is a more important factor in the disease than age, with obese felines much more susceptible.
Just as the name indicates, hepatic lipidosis is a process whereby liver cells become saturated with fat. The disease process results when a cat stops eating for three or more consecutive days.
According to Cornell Feline Health Center, most affected cats have other pre-existing illnesses such as aforementioned obesity, kidney disease, diabetes, or pancreatitis, to name a few.
Once a cat with hepatic lipidosis shows signs of liver failure such as jaundice, her prognosis without treatment is grave.
However, fatty liver survivors rarely experience a recurrence. The treatment involves aggressive and immediate nutritional support.
Sick cats must be initially hospitalized for several days. They will receive intravenous fluids to correct hydration and electrolyte imbalances. In addition, veterinarians will attempt to bring any underlying conditions under control. Critically important, these cats will receive a surgically placed stomach tube.
Even when your cat comes home, she will need tube feedings for at least an additional month. Only when your cat resumes a healthy appetite for a few days will your veterinarian remove the feeding tube.
Experts no longer consider force-feeding a viable treatment for hepatic lipidosis as your cat can develop a long-term aversion to food. If the disease is caught early enough, an appetite stimulant may prove helpful.
Cholangitis and Cholangiohepatitis
Cholangitis is inflammation of the biliary system while cholangiohepatitis also includes the liver. Suppurative cases involve infection and will be acute in nature.
Cats will need emergency support with intravenous fluids and weeks of antibiotics. Cats with suppurative hepatitis are susceptible to sepsis whereby bacteria overwhelm the entire system via the bloodstream.
Causes of nonsuppurative cholangiohepatitis are cancer, bile duct obstructions, liver flukes (leaf-shaped parasites), gallstone issues such as stones or inflammation, pancreatitis, feline infectious peritonitis, or inflammatory bowel disease.
Medications and Toxins
Cats do not have the same liver metabolic capabilities as people or even dogs. While they may require more of certain medications relative to their size to be effective, other drugs are toxic in small doses.
Some common substances that are toxic to your cat’s liver are as follows.
- Acetaminophen (Tylenol)
- Aflatoxins – Present in molds often of grain origin; Occasionally a concern in cat food
- Rodenticides – Rat poison
- Pesticides and fungicides
- Certain plants – Sago palm, Bonsaï plants
Treatment may include inducing vomiting, administering intravenous fluids, giving activated charcoal, or providing an antidote. Never induce vomiting without the advice of your veterinarian.
Feline infectious peritonitis presents in either a dry or wet form and can cause liver damage and disease. Cats with the wet form have an abdomen distended with fluid.
Cats that contract the virus suffer generalized inflammation in the abdomen that involves multiple organs.
Calicivirus is a common upper respiratory infection of kittens that can become systemic in some cats, usually adults.
Toxoplasmosis is a parasite that does not often cause disease in cats. However, it can cause acute and short-term liver disease in a few individuals.
Some purebred cats are more susceptible to specific types of liver disease.
- Mycobacterium avium is a bacterial infection that can proliferate in immune-compromised kittens such as the Somali and Abyssinian breeds
- Hepatic amyloidosis – Amyloids replace viable proteins in the liver in some Siamese, Oriental Short-Hair, and Abyssinian cats: The liver’s function becomes severely compromised
Endocrine Causes of Liver Damage
- Hyperthyroidism – Common in old cats, an overactive thyroid gland causes changes to the heart as well as the liver
Purebred cats such as the Abyssinian can be susceptible to hereditary forms of liver disease or can have compromised immune systems. Amyloidosis can affect both the kidneys and liver in this normally vibrant cat. The two Abyssinians in this video present the picture of good health.
This cat is a prime candidate for hepatic lipidosis if he were ever to stop eating. He is a middle-aged cat between five and seven years old that is severely overweight.