Animals with diabetes mellitus can be vulnerable to various complications of the liver. One of the most common liver conditions found concurrent to diabetes mellitus is hepatic lipidosis, also known as fatty liver disease. While hepatic lipidosis is believed to be more common in cats, it can also be seen in dogs with diabetes.
What is hepatic lipidosis?
Hepatic lipidosis is a medical condition characterized by accumulation of fat within the liver. Excess fat is deposited at the liver due to higher rate of fat mobilization into the liver, as opposed to out of the liver, causing impairment of liver functions. Hepatic lipidosis must be addressed in a timely manner as it may become life-threatening once it progresses to liver failure. Hepatic lipidosis often occurs secondary to underlying conditions, such as diabetes, cancer, hyperthyroidism, or pancreatitis. It is believed that a highly-contributing factor to this condition is obesity, although it is not always the case.
How does diabetes mellitus contribute to hepatic lipidosis?
The exact mechanism of how diabetes mellitus contributes to a fatty liver is not fully understood. One possible explanation is the deficiency of insulin, which is thought to have a lipolysis-suppressing effect. Lipolysis is the breakdown of triglycerides into free fatty acids, which are transported to the liver via the bloodstream.
Interestingly, hepatic lipidosis is commonly preceded by failure to eat for a prolonged time period. This fasting state can further induce the breakdown of triglycerides, as the body runs out of glucose to use for its energy source. As a result, there is an overwhelming load of fatty acids delivered to the liver to be metabolized for fuel. In response, the liver stores the excess fat within its cells.
What are the symptoms/how is it diagnosed?
Owners may notice their pets showing a significant loss of appetite, and will often be followed by weight loss. Behavioral changes, such as lethargy and/or weakness, may be observed, likely accompanying their poor food intake. Since the liver is affected, they may show jaundice, or yellowing of the skin. The yellow discoloration may also be visible in the eye, inside of the mouth, or in the ear flaps. Owners may also detect enlargement of the abdominal area or pronounced belly fat. Other possible signs are vomiting, diarrhea, and excessive drooling.
Hepatic lipidosis is diagnosed through a variety of tests, including a physical examination and a comprehensive history of diet and medications. A blood test can reveal if there have been elevations of liver enzymes, which may indicate abnormalities of the liver function. The veterinarian may also conduct an abdominal ultrasound to check for enlargement of the liver. In order to confirm the diagnosis of hepatic lipidosis, a needle aspiration or a liver biopsy is required to visualize fat globules within the liver cells.
What are the current guidelines for treatments?
The animal will likely need to be hospitalized for the first few days of being diagnosed. This is mostly to address the state of fasting through aggressive feeding. Feeding tubes may be inserted into the animal’s gastrointestinal tract via the esophagus or the stomach. The veterinarian will also address dehydration with IV fluids, and electrolyte and nutrient deficiencies with supplementation. The duration of the tube feeding varies from one to another, but once the animal is stabilized and his or her appetite returns, the owners will be advised to re-introduce oral feedings with small but frequent portions, packed with protein and calories for a balanced diet.
Another important aspect is to have the underlying condition addressed. For diabetic cats and dogs, this may require having insulin doses re-evaluated. As mentioned above, hepatic lipidosis can be deadly to the animal if left untreated. However, with the appropriate treatments, the animal is believed to have a high chance of recovery and a low rate of relapse.