Identifying and helping cats with inflammatory hepatobiliary disease - Veterinary Medicine
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Identifying and helping cats with inflammatory hepatobiliary disease
This common liver disease in cats can be acute or chronic and is caused by bacterial infections, liver fluke infestations, and many other conditions. These clinicians help you sort through the types and causes of this disease, so you can plot a course to the best outcome in affected cats.


VETERINARY MEDICINE


Cats with nonsuppurative cholangitis are generally considered to have an immune basis for their disease, so they are commonly treated with immunosuppressive drugs (Table 1). Thus, make every effort to identify and treat any underlying chronic infections. Long-term management usually involves administering short-acting corticosteroids (e.g. prednisone). In addition to directly targeting a possible immune-mediated cause, corticosteroids may provide symptomatic relief since they are anti-inflammatory and provide some degree of choleresis.1 Concurrent use of metronidazole has been recommended to modulate cell-mediated immune mechanisms involved with chronic inflammation.1 The use of chlorambucil in addition to corticosteroids has been recommended in the lymphocytic variant of the disease.1 The principal adverse effect seen with chlorambucil therapy is myelosuppression, so monitor the patient's complete blood count results for the first few months. The use of low-dose intermittent methotrexate has been suggested in cases in which severe concurrent fibrosis is noted on histologic examination (sclerosing cholangitis).1 Methotrexate can be associated with myelosuppression and gastrointestinal side effects (e.g. anorexia, vomiting, diarrhea, intestinal ulceration).

For liver fluke infestations, administer praziquantel for three consecutive days (Table 1), and reevaluate the feces for fluke eggs once the dosing regimen is complete.11-13,19 Achieving a cure is unlikely since some studies suggest that praziquantel does not completely eliminate egg production.19

Providing supportive care

Regardless of the type of feline inflammatory hepatobiliary disease, supportive care must be provided to protect hepatocytes from further damage and to promote hepatic regeneration. Immediate needs in systemically ill animals include restoring and maintaining of normal fluid and electrolyte balance.1,2


Table 2: Nonspecific Supportive Treatment of Feline Inflammatory Hepatobiliary Disease
Long-term supportive care includes attention to nutrition. Offer cats a highly palatable, calorie-dense diet to maintain body condition and nitrogen balance. Diets should not be protein-restricted unless renal azotemia (blood urea nitrogen > 80 mg/dl) or overt signs of hepatic encephalopathy (which is extremely rare) are present.1 In patients with concurrent inflammatory bowel disease or pancreatitis, consider a highly digestible, moderately fat-restricted, novel protein diet. Parenteral administration of vitamin B is recommended because chronic liver disease frequently results in cobalamin deficiency and, rarely, thiamine deficiency (Table 2).1

In cats that are anorectic for more than three or four days, consider enteral feeding either through a nasogastric tube in severely ill cats or, preferably, through an esophageal tube in cats stable enough for placement. In cases in which an exploratory celiotomy is elected, consider placing a gastrotomy tube or jejunostomy tube (in cases with concurrent acute pancreatitis). If vomiting is present, gastroprotectants and antiemetics are indicated. Famotidine is the H2-blocking agent of choice because it does not interfere with cytochrome P450 systems. A continuous-rate infusion of metoclopramide may be used to decrease nausea and prevent ileus. Concurrent use of a serotonin antagonist such as dolasetron or ondansetron may be required if nausea is not controlled.

Antioxidants such as alpha tocopherol (vitamin E) and S-adenosylmethionine (SAMe) may also be beneficial in patients with feline inflammatory hepatobiliary disease to scavenge free radicals that may be involved in perpetuating hepatocyte damage (Table 2). SAMe has been shown to modulate inflammation, promote cell replication and protein synthesis, exert cytoprotective effects, and promote sulfation and methylation reactions; it is also an important precursor of intracellular oxidants, including glutathione.20 Low glutathione concentrations are common in feline inflammatory liver diseases.21 Inadequate hepatocellular glutathione concentrations make the liver more susceptible to oxidant damage.21

In some cases of feline inflammatory hepatobiliary disease, especially those cats with evidence of cholestasis in the absence of bile duct obstruction, ursodeoxycholic acid is recommended to increase bile flow (Table 2). Additional beneficial effects of ursodeoxycholic acid may include immunomodulatory properties and suppression of hepatocellular apoptosis.1


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Source: VETERINARY MEDICINE,
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