Frequently Asked Questions - Nutrition of Dogs with Liver Disease

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Dogs with liver disease often have a decreased appetite or are anorexic. How can they be stimulated to eat?

The diet must be highly palatable and high in energy, and provide adequate protein, fat, and all essential micronutrients. Feeding small amounts frequently and slightly warming canned food can increase palatability.

Tube feeding, initially via a nasogastric tube, may be required in dogs that are anorexic for more than 3 - 5 days, since correction and prevention of malnutrition are essential to halt the vicious cycle of excessive muscle catabolism and worsening signs of liver dysfunction.

The liver biopsy of a seven-yearold Golden Retriever showed chronic hepatitis and copper accumulation.

Is this copper important?

Golden Retrievers are not known to have primary copper hepatotoxicosis, and copper accumulation is probably a consequence of cholestatic liver disease resulting in decreased biliary excretion of copper. Typically, these copper levels are not high enough to result in hepatocellular damage. However, zinc treatment together with measures for chronic liver disease will help to prevent further copper accumulation.

Are antioxidants important in managing liver disease?

Yes. There is mounting evidence that free radical production is increased in many liver diseases and it can play an important role in initiating and perpetuating liver injury. Furthermore, endogenous antioxidant systems become depleted during liver disease, which aggravates the problem.

Supplementation with antioxidants such as vitamins E, C, and S-adenosylmethionine(SAMe) helps to minimize oxidative injury. A combination of dietary antioxidants is better than a single one, since they appear to act synergistically.

Should dogs with liver disease be fed a protein-restricted diet?

Not necessarily. Protein levels are often inappropriately restricted in order to manage possible hyperammonemia. In fact, protein requirements are at least normal or even increased, and many dogs with liver disease do not have hyperammonemia. Provision of adequate high-quality proteins as well as calories is essential to ensure a positive protein balance and enable hepatic regeneration. The aim is to keep the protein intake as close to normal as can be tolerated without precipitating signs of hepatic encephalopathy (HE).

Protein restriction should only be instituted when there are signs of HE, and additional treatments such as lactulose and oral antibiotics can help to avoid excessive restriction of dietary protein.

How should I feed a dog with acute liver disease?

A dog with acute liver disease needs an ample supply of energy and protein to allow for hepatic regeneration. Protein should never be restricted; protein tolerance can be enhanced if necessary by increasing caloric content and/or using drugs (lactulose, oral antibiotics). The dog should be fed small frequent meals in order not to overload the liver’s metabolic capacity. Tube feeding should be considered if the dog remains anorexic for more than 72 hours.

What are the dietary recommendations for dogs with chronic hepatitis?

The diet should have high palatability and energy density, contain normal levels of fat (which provides energy as well as palatability), adequate levels of high quality protein (>14% of dietary calories, preferably >20%), be restricted in copper and sodium, and contain some fermentable fiber. In addition, the diet should have increased vitamin B and zinc levels, and a mixture of antioxidants (e.g. vitamin E, C and S-adenosylmethionine).

Zinc supplementation is useful because it is an antioxidant, reduces copper accumulation in the liver, can reduce the severity of HE and has antifibrotic properties.

What are the dietary recommendations for a Bedlington Terrier with copper hepatotoxicosis?

The diet should be low in copper while high in zinc, and contain adequate levels of high quality proteins. Many canine diets contain copper well above the minimum required amount, and it is important to choose a diet with levels as low as possible. Feeding copper-restricted diets slows hepatic copper accumulation but does little to lower liver copper levels in already diseased dogs with large amounts of hepatic copper.

Additional treatment with a copper chelator (D-penicillamine) will be needed, followed by life-long zinc therapy to prevent further copper accumulation.

How do I manage a dog with hepatic encephalopathy?

Firstly, determine the cause – congenital portosystemic shunt or severe liver disease. Dietary management should focus on providing adequate energy and adequate protein to support hepatic regeneration while preventing worsening of HE. Patients with signs of HE are initially offered a protein-restricted diet in combination with medication aimed at reducing colonic absorption of ammonia (lactulose, oral antibiotics).

Protein quantity is gradually increased at weekly or biweekly intervals when the dog becomes neurologically asymptomatic. Serum proteins should be monitored to prevent hypoalbuminemia, in which case dietary protein content should be increased in association with more aggressive adjunct treatment.

When HE persists despite a protein-restricted diet and adjunct medication, it may be helpful to replace meat proteins with highly digestible vegetable and/or milk proteins. Addition of soluble fiber (psyllium 1 - 3 tsp mixed with food daily) can also help by acidifying colonic contents and minimizing ammonia absorption.