High Cholesterol in Dogs (Hyperlipidemia) - Symptoms and Treatment

Just like humans, dogs can also have "high cholesterol." In animals, this condition is known as hyperlipidemia, and it should be monitored and treated as soon as possible to prevent health problems in our pet.

High-fat diets can cause hyperlipidemia, but this condition can also be secondary to significant diseases such as diabetes, hypothyroidism, liver problems, or obesity, among others.

Hyperlipidemia is detected with a simple blood test, and its treatment can range from a simple diet change to giving various medications depending on the cause. If you want to know more about this condition, below we explain its possible causes and treatment options.

What is canine hyperlipidemia?

Canine hyperlipidemia is defined as an increase above the normal amount of lipids (fats) in a fasting dog's blood (having gone without food for at least 12 hours). Hyperlipidemia includes hypercholesterolemia (high cholesterol) and hypertriglyceridemia (high triglycerides).

It's important to keep in mind that it's only considered hyperlipidemia if the animal, having fasted for at least 12 hours, shows a blood lipid concentration above the normal range for their species.

In a healthy dog, fat absorption occurs within 30-60 minutes after eating a meal, causing a natural rise in blood cholesterol and triglyceride levels that lasts between 3 and 10 hours. This "hyperlipidemia" is natural and isn't linked to any health problem.

However, if fats aren't absorbed properly due to some underlying issue, blood lipid levels can stay elevated for more than 12 hours. In this case, we'd be talking about a dog with hyperlipidemia, and the possible causes of this condition would need to be evaluated to set up proper treatment.

What types of hyperlipidemia are there?

Hyperlipidemia can be primary or secondary, depending on its cause.

• Primary hyperlipidemia: There's no underlying disease causing the change in blood lipid levels. This type of hyperlipidemia is linked to certain breeds, such as the Miniature Schnauzer, Doberman Pinscher, and Rottweiler.
• Secondary hyperlipidemia: This is the most common form of hyperlipidemia in dogs outside the breeds mentioned above, and it's secondary to other conditions such as diabetes mellitus, hypothyroidism, hyperadrenocorticism, liver disease, nephrotic syndrome, pancreatitis, or obesity. In other words, dogs with any of these conditions can have elevated blood lipid levels as a result of that underlying disease.

What symptoms can we see in dogs with high cholesterol?

The symptoms of canine hyperlipidemia mainly depend on the cause. Dogs with primary hyperlipidemia usually show no associated symptoms, though changes such as abdominal pain, vomiting, diarrhea, seizures, or fatty skin lumps (lipomas) can appear.

If it's secondary hyperlipidemia, besides the symptoms mentioned above for primary hyperlipidemia, specific signs of the underlying disease can be seen.

• Diabetes mellitus: Signs include increased appetite, increased water intake, higher urine volume, and weight loss.
• Hypothyroidism: Symptoms that can be seen include lack of activity (lethargy), seeking out warmth, and skin changes (hair loss and darkened skin).
• Hyperadrenocorticism: Signs include increased appetite, increased water intake, higher urine volume, skin changes (hair loss and thin skin), and a pot-bellied abdomen.
• Liver disease: Symptoms observed can include loss of appetite, weight loss, and jaundice (yellow discoloration of the mucous membranes).
• Nephrotic syndrome: Signs include swelling in the limbs and fluid buildup in the abdomen (ascites).
• Pancreatitis: Symptoms include abdominal pain, vomiting, diarrhea, and loss of appetite.

Diagnosing canine hyperlipidemia

Diagnosing hyperlipidemia is very simple, since it's detected with a blood test done on the dog after a minimum of 12 hours of fasting.

The challenge lies in, once hyperlipidemia is detected, running all the necessary tests to determine the cause of this condition.

If it's one of the predisposed breeds (Miniature Schnauzer, Doberman Pinscher, Rottweiler) and shows no symptoms, it can be determined with near certainty that it's primary hyperlipidemia, and no additional tests will be needed.

However, in other breeds, or if there's any associated symptom, the underlying diseases mentioned above need to be ruled out as possible causes of secondary hyperlipidemia.

How is canine hyperlipidemia treated?

If it's primary hyperlipidemia, the basis for treatment is switching to a low-fat diet (the diet should contain <10% fat). After 4-6 weeks, the diet's effectiveness is assessed, and if diet alone hasn't managed to control the hyperlipidemia, additional supplements or medications will be needed, such as omega-3 fatty acids, gemfibrozil, clofibrate, and niacin.

In cases of secondary hyperlipidemia, setting up specific treatment for the underlying disease usually corrects the blood lipid levels. However, in some cases, a diet change and specific medication to lower lipid levels are also needed.

Can hyperlipidemia be prevented?

If your dog is one of the breeds predisposed to primary hyperlipidemia, we recommend following these tips to avoid problems related to this condition.

• Try to keep your dog at their optimal weight; to do this, control the amount of fat in the diet you choose to feed them, and avoid human food, especially anything containing fat.
• Also, regular exercise helps "burn" fat and will help them maintain their weight.
• Lastly, it's recommended to see your vet at least once a year for a check-up, so any health problem can be caught as early as possible.

Bibliography Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.