Page 619 - Small Animal Internal Medicine, 6th Edition

CHAPTER 36 Hepatobiliary Diseases in the Dog 591

TABLE 36.2
VetBooks.ir Dietary Considerations for Dogs With Liver Disease*

DIETARY
COMPONENT RECOMMENDATIONS

Protein Normal amount – avoid low and high protein foods
High-quality (optimal amounts of all essential amino acids)
Highly digestible
Ideal protein source may be dairy or vegetable
(Reduced aromatic amino acids and increased branched-chain amino may reduce hepatic
encephalopathy—evidence lacking.)
Ornithine aspartate may reduce hepatic encephalopathy—one small pilot study in dogs (Ahn et al., 2016)
Proprietary liver diets or GI diets or hypoallergenic diets are ideal
Fat No special advice for liver disease—fat restriction usually unnecessary even with biliary tract disease.
Optimizing omega-3–omega-6 may help reduce inflammation (more research is needed).
Carbohydrate No special advice for liver disease except highly digestible as a calorie source, reducing the need for
hepatic gluconeogenesis from fat and protein.
Fiber Ideal is moderate amount of mixed fiber source
Fermentable fiber (e.g., lactulose) may reduce hepatic encephalopathy (conflicting evidence in humans,
little evidence in dogs)—broken down to short-chain fatty acids in the colon, trapping ammonia as
ammonium, increasing nitrogen incorporation into bacteria and reducing ammonia production.
Nonfermentable fiber prevents constipation, a potential predisposing factor for development of
encephalopathy
Minerals
Zinc Zinc indicated in copper storage disease—reduces copper absorption from gut and copper availability in
the liver. Do not supplement when dog is on copper chelators as zinc will compete with copper for
chelation.
Zinc supplementation may be helpful in chronic hepatitis with hepatic encephalopathy—extrapolated from
humans and no evidence in dogs
Copper Animals with copper storage disease should be maintained on a low-copper, high-zinc diet.
Vitamins
Fat-soluble Vitamin E supplementation may be cytoprotective, especially in copper toxicity, because of its antioxidant
effect.
Vitamin K supplementation may be necessary if clotting times are prolonged, especially in cats and
particularly if considering biopsies.
Vitamins A and D should not be supplemented. Vitamin A can cause hepatic damage, and vitamin D
supplementation can cause calcification in tissues.
Water-soluble B vitamins may be supplemented because there is potential increased loss in polydipsia/polyuria
associated with liver disease.
Vitamin C should not be supplemented because ascorbate can increase the tissue damage associated with
copper and iron in liver disease.
*The diet should be fed little and often (four to six times daily) and needs to be palatable. A good and sufficient diet is essential for hepatic
regeneration and optimal hepatic function.

is included in many nutraceuticals marketed for dogs with vacuolar and toxic hepatopathies in dogs and cats, and can
liver disease. One study (Filburn et al., 2007) showed that be safely used without a biopsy. However, the clinician must
it had very poor absorption alone but was more bioavail- be aware of the emerging nature of the information about
able when complexed with phosphatidylcholine. Denamarin their bioavailability and efficacy, and choose products care-
(Nutramax Laboratories) contains both SAM-e and silybin fully with this in mind.
in reportedly bioavailable forms, although published data Copper chelators
supporting this are currently lacking. Any dog with chronic hepatitis and an excess of copper
Antioxidant nutraceuticals have great potential benefits on biopsies should be treated with copper chelators and a
for the treatment of chronic liver disease in dogs as well as low copper diet (see “Copper Storage Disease” section for