Dogs with hyperlipidemia, also called lipemia, have higher than normal amounts of triglycerides and/or cholesterol in their blood stream. When triglycerides are elevated, a sample of the dog’s blood can look a bit like a strawberry smoothie (sorry for the food reference), while the serum, the liquid part of blood that remains after all the cells have been removed, will have a distinctly milky appearance.
Hyperlipidemia can have several causes, the most common of which is a normal physiological response that occurs after a dog has eaten a meal containing moderate to high levels of fat. Blood lipid levels generally fall back into the normal range 6-12 hours after eating. Therefore, the first thing a veterinarian will do when faced with a dog with hyperlipidemia is to repeat the testing on a sample of blood that was unquestionably taken after a 12 hour fast.
If hyperlipidemia persists despite fasting, my next step is to rule out other diseases that can cause fat levels in the blood to rise. Diabetes mellitus, Cushing’s disease, pancreatitis, hypothyroidism, and a type of kidney disease that causes protein to be lost into the urine are the most common primary diseases that can result in hyperlipidemia. Adequately controlling the primary problem in these cases will usually take care of the hyperlipidemia as well.
Retesting a fasted serum sample and a thorough health work-up to rule out other diseases will eliminate most cases of hyperlipidemia … unless the dog in question in a schnauzer. This breed is predisposed to a condition called idiopathic hyperlipidemia. “Idiopathic” simply means that we’re not sure of the cause, though in this case an inherited deficiency in lipoprotein lipase, an enzyme needed for normal lipid metabolism, is suspected. Other breeds can also be affected by idiopathic hyperlipidemia, but it is seen at a much lower rate.
Some dogs with hyperlipidemia have no clinical signs while others become quite sick. Symptoms of hyperlipidemia can include:
- loss of appetite
- abdominal pain
- eye disorders
- skin problems
- abnormal behavior
Dogs with hyperlipidemia are at higher than average risk for a very serious form of pancreatitis, so fat levels in the blood should be reduced even if the dog is currently asymptomatic.
Dietary changes are at the center of treating idiopathic hyperlipidemia. Mild cases may respond to over the counter low fat dog foods, but more significantly affected individuals will benefit from eating one of the very fat restricted diets that are available by prescription only. Since fat plays an important role in palatability, getting dogs to eat these foods can be challenging. When this is a problem, feeding the dog a home-prepared diet based on a recipe formulated by a veterinary nutritionist will usually do the trick.
If dietary changes alone aren’t sufficient, omega-3 fatty acid supplements, niacin (a type of B-vitamin), or chitin (a fiber supplement that comes from shellfish) are worth a try. Some veterinarians will also prescribe gemfibrozil, a drug that can reduce the body’s production of tryglicerides and other fats, but clinical experience with the medication is very limited.
Dr. Jennifer Coates