Frequently Asked Questions: Canine Hyperlipidemia

Q

A

What causes serum to be turbid?

Elevated serum triglyceride carried by lipoproteins causes serum to appear turbid. Opacity is seen when triglyceride concentration approaches 600 mg/dL. Serum may have the appearance of whole milk when triglyceride concentrations reach 2500 - 4000 mg/dL.

What conditions cause hyperlipidemia?

The most common cause is a non-fasted animal. If fasting for greater than 12 hours is confirmed, then primary hyperlipidemia, or secondary hyperlipidemia due to hypothyroidism, pancreatitis, diabetes mellitus, hyperadrenocorticism, cholestasis, or nephrotic syndrome may be present.

Is primary hyperlipoproteinemia hereditary?

Since hyperlipoproteinemias appear to be more common in certain breeds, some defects in lipid metabolism may be hereditary. However, it is likely that primary hyperlipoproteinemia may represent a number of different lipid metabolic defects which may or may not be hereditary in nature.

Are high fat diets harmful to dogs?

Not usually. Lipid metabolism in dogs is very different from that in humans. Dogs carry most of their cholesterol in HDL, and are very resistant to the development of atherosclerosis. However, if certain other diseases are present such as hypothyroidism or diabetes mellitus, high fat diets could result in further lipid abnormalities.

What causes a "cream layer" to separate in some turbid serum samples?

The "cream layer" which floats to the top of serum is due to the presence of chylomicrons. This is normal in a non-fasted animal, but represents an abnormality if the animal has been fasted for greater than 12 hours.

Do dogs develop atherosclerosis?

Unlike humans, dogs rarely develop atherosclerosis due to differences in lipid metabolism. Atherosclerosis may develop in some dogs that have another concurrent disease that causes chronic hyperlipidemia.

Should persistent fasting hyperlipidemia be treated?

Yes. If the hyperlipidemia is due to a secondary cause, then treatment of the underlying condition may resolve the hyperlipidemia. There is evidence suggesting that chronic hyperlipidemia may lead to the development of pancreatitis, insulin resistance, diabetes mellitus, or atherosclerosis in some dogs.