When a dog’s cholesterol levels rise, what does it mean for daily feeding and care?
High blood cholesterol levels in people are a well-recognized risk factor for heart attack or stroke. Many of us are on low-fat diets or may take medication to minimize that risk. Should we be worried that our canine companions are also at risk?
Fortunately, it is rare for dogs to suffer from arteriosclerosis, an accumulation of cholesterol inside the arteries that causes the narrowing and obstruction responsible for heart attack or stroke. High levels of triglycerides, another form of fat, are more apt to cause problems for dogs than cholesterol.
Hyperlipidemia in dogs
Dogs can have increased fat in their blood, which is called hyperlipidemia, in the form of both triglycerides and cholesterol. When detected on a screening blood test, the most common cause is a recent meal. If the levels seem especially high, the veterinarian may recommend repeating the sample after at least 12 hours of fasting. If the values remain abnormal, further work-up by your veterinarian is warranted.
Most hyperlipidemia in dogs is secondary to other diseases, and testing to find these is important. The most common causes are:
Hypothyroidism, meaning low thyroid production
Hyperadrenocorticism, an overactive adrenal gland
Pancreatitis, inflammation of the pancreas
Occasionally dogs may have gall bladder or kidney problems. If untreated, these disorders can make your pet quite ill. Sometimes hyperlipidemia is the first symptom that leads to early detection of these diseases.
Breed predisposition to hyperlipidemia
Certain breeds are predisposed to primary hyperlipidemia, where no underlying disease is identified. High triglycerides are especially common in Miniature Schnauzers, particularly those middle-aged and older. The likely cause is a deficiency in an enzyme that helps metabolize fats. High triglycerides are also common in Miniature Poodles and Beagles. Collies and Shetland Sheepdogs are predisposed to high cholesterol without high triglycerides.
Clinical signs in canines
Dogs with hyperlipidemia may have no clinical signs, especially with mild to moderate elevations. White lipid deposits in the corneas of the eyes can be a common mild symptom. Some dogs, however, will experience abdominal discomfort, vomiting and diarrhea. Prolonged elevations can lead to pancreatitis, which can be life threatening. If triglyceride levels are quite high, central nervous system signs, including seizures, are possible.
Treatment of your dog’s hyperlipidemia
The first goal is to identify and treat any underlying disease. For primary hyperlipidemia or as an adjunct to treatment for other causative diseases, dogs may need to begin a low-fat diet.
Ask your veterinarian before feeding your dog a low-fat diet.
Not just any so-called “low-fat” diet will be effective. Specially formulated diets are available through your veterinarian, or pet owners can work with a nutritionist to design an appropriate homemade diet. Ironically, addition of fatty acid supplements is essential to decrease secretion of certain lipoproteins by the liver.
Dogs whose high triglycerides cannot be controlled by these measures may need to receive medication. Fortunately, these cases are not common. Gemfibrozil is a drug that decreases the production of triglycerides and certain cholesterols. It can be given twice daily when necessary. Chitin and Niacin are other drugs that may be prescribed.
In the rare cases where a dog’s cholesterol is elevated without an elevation of triglycerides and diet alone is ineffective, statins may be prescribed. Cholesterol-lowering statins are one of the most common medications prescribed for people, but almost never necessary in dogs.
The bottom line on high cholesterol in dogs
High cholesterol in our dogs is rarely the danger sign it can be in us. However, especially if accompanied by elevated triglycerides, it can cause illness or be an early symptom of other disorders. If your pet’s fasting cholesterol levels are high, please discuss further testing with your veterinarian. Early detection of other disease leads to the most effective treatment.