High Cholesterol in Pets
Hyperlipidemia is a condition in which the amount of fats (also called lipids) in the blood are elevated. The most important lipids are cholesterol and triglyceride. Hyperlipidemia primarily causes heart-related disease in humans and is responsible for 500,000+ American deaths each year. 52 million adults change their diet and 13 million adults must use lipid-lowering medication to lower their cholesterol and triglyceride levels into safe ranges.
Despite the attention hyperlipidemia has received in humans, it has largely been overlooked in pets. This is because it is rare for dogs and cats to develop heart disease related to hyperlipidemia like people. However, hyperlipidemia has been associated with serious and sometimes fatal ailments such as pet obesity, pancreatitis, vision and neurologic problems. Although both dogs and cats can develop hyperlipidemia, it is much more common in dogs, particularly in the Schnauzer breed. The remainder of this article will focus on diagnosing and treating this common dog health problem.
Causes of Hyperlipidemia
It is normal for hyperlipidemia to occur in all pets for a few hours after eating. The cholesterol and triglyceride levels then return to normal due to the action of fat metabolism enzymes. If your dog has a deficiency of or a defect in these enzymes, they will be unable to clear the fat from their blood stream, which results in persistently high fat levels. It is suspected that many Schnauzer dogs have a genetic predisposition to hyperlipidemia due to defective enzymes. A study performed in 192 healthy Schnauzers revealed that 33% have elevated triglycerides compared to only 5% of dogs of other breeds. In this study 75% of healthy Schnauzers over 9 years old had moderate to severe hyperlipidemia, indicating there is increased risk of hyperlipidemia with aging.
Hyperlipidemia can also develop related to canine diabetes, hypothyroidism, Cushing's disease (hyperadrenocorticism), liver disease, canine pancreatitis and certain kidney diseases. It is important to have your veterinarian check for these dog illnesses if hyperlipidemia is identified.
Symptoms of Hyperlipidemia
The symptoms of hyperlipidemia are variable and range from asymptomatic (no symptoms) to severe episodes of canine pancreatitis, vision disturbances and seizures. Most dogs with hyperlipidemia will exhibit intermittent signs of vomiting, diarrhea and/or abdominal discomfort.
Diagnosis of Hyperlipidemia
Hyperlipidemia is diagnosed if your pet has a fasted triglyceride level greater than 500mg/dl and/or a fasted cholesterol level greater than 300mg/dl. Cholesterol and triglyceride levels are part of basic blood work and many times elevations are overlooked if dogs are not sick or were not fasted for their blood sample.
As a pet owner (especially if you have a Schnauzer), always inquire about the triglyceride and cholesterol values and if there are elevations after proper fasting (12-18 hours), treatment is indicated to prevent more serious symptoms.
Every dog with hyperlipidemia requires a full history, physical exam, complete blood count, biochemistry profile, thyroid concentration and urinalysis. Additional tests such as bile acids, abdominal ultrasound and evaluation for Cushing’s disease may be required. If an underlying disease is identified, hyperlipidemia will usually improve or resolve with correction of that disease.
Treatment and Monitoring of Hyperlipidemia
If no underlying disease is identified, a diagnosis of familial (genetic) hyperlipidemia is made and treatment includes a low fat diet, fatty acid supplementation and occasionally medication.
Most dogs (especially Schnauzer breed) require a low fat (<20%DM) or ultra low fat (10-12%DM) diet to lower their fat levels significantly. The chicken and salmon varieties of Spot's Stew are low in fat and may work well for several dogs with hyperlipidemia. Ask your veterinarian to help you select a diet as there may be many factors to consider for your dog. Treats should be restricted to 5% of the daily calorie intake and be low fat as well. The chicken and salmon Liv-a-Littles Natural Treats are an excellent low-fat treat to consider in a dog with hyperlipidemia. In addition to providing a low fat diet, if pet obesity is a problem, calorie restriction will promote weight loss and help decrease the production of “bad” cholesterol from excess calories.
Cholesterol and triglycerides should be rechecked after four weeks of feeding a low fat diet. If the values are still too high, make sure there are no extra fat calories from treats (including dog walkers and neighbors!) and a more fat restricted diet should be tried, as there is marked individual variation in the response to each diet. It is not uncommon for some hyperlipidemic dogs to require an ultra low fat, homemade dog food. Your veterinarian can help you obtain a nutrition consultation and create a designer diet for your dog if required.
Pet supplements and fish oils that contain omega-3 fatty acids can very effectively lower triglyceride concentrations. When these supplements are used with a low fat diet, successful control of hyperlipidemia is often achieved.
Lipid-lowering medication (statins, niacin, fibric acid, etc) should be started if the cholesterol or triglyceride remains elevated after 4 weeks of both a low fat diet and fatty acid supplementation. It is important to exhaust other options before beginning these drugs as side effects such as vomiting, diarrhea, and liver toxicity are possible. There are many medications available and some more effectively lower cholesterol while others more effectively lower triglycerides. Ask your veterinarian which medication would be best for your dog.
Hyperlipidemia is a common and under-diagnosed dog health problem that can negatively impact health and longevity. Working with your veterinarian can assist in the early diagnosis and treatment of this condition in your dog, resulting in increased quality of life and prevention of serious dog illnesses.
Donna Spector, DVM, DACVIM, ,is a renowned, board-certified Veterinary Internal Medicine Specialist who has practiced at the Animal Medical Center in New York City and other leading institutions. She is an active member of the American Veterinary Medical Association (AVMA) and the American Holistic Veterinary Medical Association. Dr. Donna has written and lectured extensively on topics including nutrition, diabetes, gastrointestinal disorders, kidney failure and respiratory disease. She is widely recognized for her role as consulting veterinarian to HALO, Purely for Pets, her TV appearances with Ellen DeGeneres and her widely-quoted pet health advice in print and on radio. Dr. Donna performs medical, nutrition and weight loss consultations for dogs and cats through her web-based veterinary consulting service, www.SpectorDVM.com.