Cholangiohepatitis in Cats
Dr. Bari Spielman
A complete blood count (CBC) may be within normal limits, or may reveal a mild anemia and/or an elevation in white blood cell count.
Certain diagnostic tests must be performed to make a definitive diagnosis of cholangiohepatitis and, as importantly, exclude other disease processes that may cause similar symptoms. Obtaining a complete history, description of clinical signs, and thorough physical examination are all important in obtaining a diagnosis. Ultimately, a liver biopsy is necessary to obtain a definitive diagnosis.
The following tests are recommended to rule out other disorders and to confirm a diagnosis of cholangiohepatitis.
A biochemical profile usually reveals elevations in liver enzymes, and may reveal electrolyte abnormalities, an elevated bilirubin, low albumin (a protein), elevated globulin (a protein), low blood sugar, low blood urea nitrogen and low cholesterol. It also may help rule out other disease processes.
A urinalysis helps assess the kidneys and level of hydration of the patient and may reveal bilirubin in some cases.
A coagulogram (clotting profile) should be assessed, as clotting disorders are not uncommon with liver disease.
Serum bile acids are paired blood tests obtained before and after a meal that evaluates liver function. This is the test of choice to assess liver function. The test is very safe and can be performed at your local veterinary hospital.
Ammonia levels are blood tests that when abnormal, often correlate with liver disease. Test inaccuracy is a concern, as many factors affect test results, and special handling is necessary.
Abdominal radiographs (X-rays) may be within normal limits, although may reveal enlarged liver (hepatomegaly), gallstones (cholelithiasis), and occasionally, fluid in the abdomen (ascites).
Abdominal ultrasound is recommended in most cases to evaluate all of the abdominal organs, including the liver. It is equally important to rule out other disorders or diseases that may initially be difficult to differentiate from or associated with cholangiohepatitis. With the guidance of ultrasound, it is often possible to obtain a sample of the liver via aspirate or biopsy for evaluation and culture/sensitivity. A clotting profile should be performed first, and tissue should only obtained if the clotting parameters are within normal limits.
Ultrasound is often considered the diagnostic tool of choice. The ultrasound itself is a noninvasive procedure, although sampling of the tissue will often necessitate sedation or general anesthesia, and is associated with some minor risks. These procedures generally necessitate the expertise of a specialist and/or referral hospital.
Your veterinarian may recommend additional tests to exclude or diagnose concurrent conditions, or more definitively diagnose cholangiohepatitis. These tests are not necessary in every case, however may be of benefit in certain individuals, and are selected on a case-by-case basis. These include;
Laparoscopy. This procedure allows visualization and sampling of abdominal structures by an instrument introduced through a tiny incision. It is more invasive than ultrasound-guided biopsies, although it allows direct visualization of the liver and associated structures and generally facilitates a larger biopsy. It necessitates general anesthesia, however, and should be performed by an individual and facility that are experienced and have the appropriate instruments.
Laparotomy. Abdominal exploratory surgery allows close inspection of the entire liver and other abdominal structures. It allows large biopsy samples to be obtained, and may be indicated in cases where an extrahepatic biliary obstruction needs to be relieved and diverted. This procedure should be left to an individual who has experience and expertise, and performed in a facility where close postoperative monitoring is available.
Patients with cholangiohepatitis may need to be hospitalized and treated aggressively. Depending on the stage of disease and clinical signs involved, outpatient therapy may or may not be sufficient. It is extremely important to have a diagnosis confirming the exact type of cholangiohepatitis involved, as treatment protocols will vary.
Hospitalization and support (fluid and electrolyte therapy) should be instituted as needed for dehydration and electrolyte disturbances from severe vomiting and diarrhea.
Providing nutritional support through parenteral (intravenous) routes may be needed in some cases.
Attend to any underlying cause such as inflammatory bowel disease or pancreatitis. Surgery may be indicated to address underlying causes such as cholecystitis, cholelithiasis, and extrahepatic biliary obstruction.
Antibiotic therapy is indicated in cases of suppurative cholangiohepatitis. Initially, while pending the culture and sensitivity report on the liver and/or bile, a broad spectrum antibiotic, such as Ampicillin, should be instituted. A three to six month course of antibiotics should be continued as dictated by the sensitivity pattern. Metronidazole (Flagyl®) has been recommended for both forms of the disease, as not only is it an excellent antibiotic for anaerobic infections (a type of infection), it also has anti-inflammatory and immune modulation properties as well.
Immunomodulatory drugs (drugs that alter the immune system), specifically corticosteroids (prednisolone), are used in the treatment of the nonsuppurative form for their anti-inflammatory and immunosuppressive qualities. Continuous or intermittent therapy may be recommended on a long-term basis. Other agents have been used in conjunction with corticosteroids with variable results.
Diuretics (drugs that facilitate removal of fluid) such as spironolactone (Aldactone®) may be indicated in cases with ascites.
Choleretic drugs (drugs that enhance bile flow) such ursodeoxycholic acid (Actigal®) are recommended as they thin bile and enhance flow through the biliary tract. Additionally, they act as anti-inflammatory agents in conjunction with other drugs.
Treatment for hepatic encephalopathy (a disorder affecting the central nervous system secondary to advanced liver disease) is indicated when present. Lactulose, a substance that slows absorption of ammonia from the intestinal tract, should be administered orally. It can also be used rectally as an enema, when diluted with warm water. Antibiotics, such as neomycin or metronidazole are also recommended in conjunction with lactulose.
Dietary recommendations for animals with liver disease include protein modification. A major dilemma in formulating diets for animals with liver disease is the fact that these animals are often malnourished, and it is vitally important to maintain body weight and muscle mass while minimizing the signs of liver failure. There are prescription diets that are designed to provide reduced levels of high quality protein, such as Hill's Prescription Diet L/D®, as well as ways to formulate homemade diets to provide similar benefits.
Vitamin supplementation including injectable vitamin K and water soluble vitamins are indicated.