While the term hyperbilirubinemia may not be familiar, you may actually know the condition it refers to. Known also as jaundice, hyperbilirubinemia is the increase of bilirubin, or red blood cell waste in the body, resulting in yellow skin coloration. Hyperbilirubinemia is not a disease, but rather a symptom of an underlying condition. In dogs, jaundice typically occurs as the result of three main causes, with treatment focusing on which underlying condition is to blame.
More Than Just Yellow Skin
As toxic levels of bilirubin build up in the body, the noticeable symptom is the yellow coloration of the skin. In dogs, this is best seen in the gums, eyes and inner ear flaps. Other symptoms associated with hyperbilirubinemia include vomiting, diarrhea, fever, loss of appetite, increased thirst and weight loss. In addition, urine frequency may increase and the urine may develop an orange tint.
Common Conditions Resulting in Hyperbilirubinemia
In dogs, conditions that cause hyperbilirubinemia fall into three categories -- hemolysis, liver disease and bile duct obstruction. Hemolysis occurs when red blood cells break down and die faster than normal. This increased level of cell waste contributes to increased bilirubin. Common causes of hemolysis in dogs include parasites, heartworm disease, autoimmune conditions, cancers, certain medications and toxic plant ingestion. Many of these same causes can also contribute to liver disease. Common causes of bile duct obstructions include pancreatitis and gallstones.
Diagnosing the Underlying Condition
If your dog displays symptoms of hyperbilirubinemia, seek veterinary care immediately. The first thing the veterinarian will do is run tests to determine the underlying cause. Initial tests require a blood and urine sample to evaluate blood cells, look for liver enzymes and check bilirubin levels. Depending on the results, other tests may include X-rays, ultrasounds and a liver biopsy.
Dog Breed Predisposition
While hyperbilirubinemia can occur in any breed, certain breeds are predisposed to conditions that commonly cause increased bilirubin. Poodles, Old English sheepdogs, Irish setters, cocker spaniels, Basenjis, beagles and West Highland terriers have a greater risk of developing hemolysis. Miniature schnauzers, retrievers, Cairn terriers, Old English sheepdogs, Australian cattle dogs, West Highland terriers, Dobermans, skye terriers and Irish wolfhounds have an increased risk of liver disease.
Treatment Focuses on the Underlying Condition
Because hyperbilirubinemia is a symptom rather than a condition, treatment must focus on the underlying condition. Treatment options range from medications, such as corticosteroids to treat immune-mediated hemolysis, to surgery to correct bile duct obstructions.