High Cholesterol in Cats

High cholesterol can either be a primary condition or a secondary condition that results from an underlying disorder, such as diabetes mellitus. Prompt care is necessary in order to both lower the high cholesterol levels to normal levels and treat any accompanying conditions that caused it to occur.

High cholesterol, also known as hyperlipidemia, is a lipid metabolic disorder that is characterized by high levels of fatty substances or fat in the bloodstream. After a cat eats a meal, triglycerides and cholesterol are formed from the fats that are consumed. Lipoproteins work to deliver these fats to the various organs in the body for proper body function. Normally these consumed fats raise a cat's cholesterol levels for three to ten hours after eating. Elevated cholesterol levels more than 12 hours after eating are indicative of high cholesterol.

Symptoms may be mild and become more pronounced if the cat's cholesterol has been high for a long period of time. These symptoms include:

• Abdominal pain
• Abdominal distention
• Fever
• Loss of appetite
• Weight loss
• Vomiting
• Diarrhea
• Dehydration
• Seizures
• White appearance of the retina (lipemia retinalis)
• Excess blood cells in the eye (lipemic aqueous humor)
• Tibial nerve paralysis
• Radial nerve paralysis
• Horner's syndrome 
• Small orange-colored bumps on the skin that are filled with a fatty substance (cutaneous xanthomata)

High cholesterol as a primary condition is rare in cats, due to the way that cats are able to metabolize consumed fats. Because of this, high cholesterol is typically seen as a symptom of another condition. The conditions that can cause high cholesterol include:

• Thyroid problems
• Diabetes mellitus
• Adrenal gland problems
• Inflammation of the pancreas (pancreatitis)
• Bile duct obstruction (cholestasis)
• Genetics
• Pregnancy
• Cholesterol ester storage disease (chylomicronemia)
• Defects in lipid carrier proteins or enzymes
• Consumption of a fatty meal
• Nephrotic syndrome (kidney disorder)

The veterinarian will need to know the cat's complete health history, which will include any recent dietary changes, a detailed list of all of the symptoms the cat is experiencing, when the symptoms began and any other conditions that may have caused the high cholesterol levels to occur. The veterinarian will physically examine the cat, looking for any signs of cutaneous xanthomata, feeling for abdominal distention and examining the cat's eyes.

The cat will most likely need to be hospitalized in order to properly test the cat's cholesterol levels. The cat will need to fast for 12 hours before having its labs done. A complete blood count, biochemical analysis, chemical blood profile and urinalysis will be taken. If the total cholesterol levels are over 200 mg/dL or the triglyceride level is over 100 mg/dL, the cat will be diagnosed with hyperlipidemia.

The veterinarian will look for other conditions or diseases in the labs that may have caused the high cholesterol levels. These other conditions may need additional testing for proper diagnosis, which may include ultrasounds, X-rays or additional labs, such as a blood test to look for thyroid problems.

Dietary Changes

The cat will be placed on a low-fat diet with moderate protein intake. This diet typically is high in fiber and contains less than 10 percent fat.

Supplements

Fish oil supplements have been found to be helpful in lowering high triglyceride levels. If dietary changes haven't lowered the cat's triglyceride levels enough, the veterinarian may prescribe omega-3 fatty acid fish oil supplements to help.

Insulin

Cats who have high cholesterol levels due to diabetes will be given a prescription for insulin injections. Once blood sugar levels have stabilized, cholesterol levels will decrease.

Medication

If dietary changes, supplements, and treatment of any primary conditions do not lower cholesterol to the proper levels, then the veterinarian may prescribe medications to help. These medications may include niacin, which lowers triglyceride production; chitosan, which reduces the absorption of consumed fats; and gemfibrozil, which increases the production of the lipoprotein lipase. Because of the risk of unwanted side effects, however, medications are prescribed only in extreme cases.

The cat will need to be frequently re-tested in order to determine the effectiveness of the dietary changes and/or medications. Additional follow-up appointments and treatment will be necessary to treat any underlying conditions. It's important to keep all follow-up appointments in order to prevent pancreatitis from occurring due to high levels of fat in the blood. With dietary restrictions and prompt treatment, the prognosis is good for cats with high cholesterol levels.