The liver is an integral part of the gastrointestinal system, so it's no surprise that patients with liver disease have very specific nutritional requirements. The authors of this article discuss nutritional factors to consider when formulating a dietary management plan for patients with liver disease.
In this article, the authors begin by presenting an overview of the common clinical signs associated with liver disease. The clinical signs vary depending on the underlying cause but often include vomiting, diarrhea, jaundice, hyporexia, polyuria and polydipsia.
To help increase food intake in these patients, the authors discuss tactics such as warming the food, feeding by hand, or using appetite stimulants such as mirtazapine or cyproheptadine. They note, however, that the optimal dose of these medications in patients with liver disease is not known.
Each of the major dietary components is discussed individually with respect to their use in managing patients with liver disease.
- Energy-dense diets are often required to meet the daily energy requirements of anorectic or hyporectic patients. Feeding tubes (e.g. an esophagostomy or a gastrostomy tube) may be required in patients with severe disease or prolonged anorexia.
- For patients that are overweight, hold off on implementing a weight loss plan until the underlying disease is treated.
- Liver dysfunction in these patients can lead to alterations in glucose metabolism, resulting in a tendency for patients to become hyperglycemic or hypoglycemic. An increase in soluble carbohydrates in the diet is called for with patients that tend toward hypoglycemia.
- There are no standardized requirements for carbohydrates in dog or cat diets; adjustments will depend on patient needs.
- In patients that tend to become hypoglycemic, use highly digestible carbohydrates such as white rice, and avoid complex carbohydrates such as whole grains.
- Take care when providing soluble carbohydrates to patients with prolonged anorexia. Hyperglycemia and derangements in phosphorous, magnesium and potassium can occur (“refeeding syndrome”) and may require parenteral supplementation during hospitalization.
- Closely monitor serum electrolyte, phosphorous, magnesium and glucose concentrations during the first four to seven days of refeeding.
- Diets that include soluble fiber may be beneficial in reducing enteric ammonia production and increasing fecal bile acid excretion; this will be of particular benefit in patients with hepatic encephalopathy.
- The crude fiber listed in the nutrient analysis of commercial foods does not include the soluble fiber content.
- Psyllium husk is a soluble fiber that can be added to the diet.
- Adverse effects of dietary fiber may include reduced nutrient absorption, decreased palatability and decreased energy density.
- Liver disease can result in altered fat metabolism and utilization.
- The ideal amount of fat in the diet is unknown and will depend on the underlying disease and concurrent medical issues.
- Fat in the diet will increase palatability and energy density.
- Diets with increased fat are contraindicated in overweight patients (body condition score > 5/9), those with a history of pancreatitis or hyperlipidemia, and those with severe cholestatic disease.
- Protein restriction is not required in patients with liver disease unless there are clinical signs of hepatic encephalopathy (HE).
- For patients without HE, recommended dietary protein concentrations are > 18% dry mater basis (DM) for adult dogs (51.4 g protein/1,000 kcal) and 26% for adult cats (65 g protein/1,000 kcal).
- For patients with HE:
- Minimum requirements are 10% DM, 25 g protein/1,000 kcal for adult dogs and 20% DM, 50 g protein/1,000 kcal for adult cats; however, protein restriction beyond this may be required to alleviate signs of HE.
- Use of plant-based and dairy proteins may prolong the time to the development of HE.
- Even if protein restriction is required, be sure to meet the minimum requirements for taurine and arginine; adult cats require 0.1% DM extruded diets (250 mg/1,000 kcal) or 0.2% DM canned diets (500 mg/1,000 kcal) of taurine and 1.04% DM (2.6 g/1,000 kcal) of arginine.
- Taurine supplementation is not required in patients receiving a commercial, protein-restricted diet but should be considered for those on a home-made diet.
- Taurine supplementation is recommended for patients that are documented as having taurine deficiency based on blood testing, those on taurine-deficient diets, or for those with evidence of dilated cardiomyopathy. For dogs, the doses are given two to three times a day: 50 to 1,000 mg for small dogs, 1,000 to 2,000 mg for large dogs. Dosage for cats: 500 to 1,000 mg daily.
Vitamins and minerals
- Patients with prolonged anorexia will benefit from supplementation of B vitamins.
- Vitamin K deficiency will develop in patients with chronic bile duct obstruction or antibiotic therapy; supplementation at 1 to 5 mg/kg/day of phytonadione (vitamin K1) is recommended.
- Antioxidant support may be provided via supplementation of vitamin E (50 to 400 IU/day) and vitamin C (500 to 1,000 IU/day) in patients with liver disease. Vitamin C should not be supplemented in patients with suspected or confirmed copper storage disease.
- For patients with known or suspected copper storage disease.
- Avoid diets that contain liver, organ meats, shellfish, legumes, nuts or mushrooms.
- After chelation therapy, commercial or home-made diets with reduced copper content are recommended. Dietary copper concentrations should be < 5 mg/kg DM or < 1.25 mg/1,000 kcal.
- After copper chelation therapy, consider supplementation with zinc acetate or zinc gluconate. Obtain serum zinc concentrations at baseline, in seven to 14 days, at two months and at six months after initiating supplementation.
- Supplements may provide antioxidant support for hepatocellular repair.
- Options include: S-adenosylmethionine (20 mg/kg/day) or silymarin: 50 to 250 mg/day.
Patients with liver disease will require special dietary considerations, but dietary management will require an individualized approach that takes the underlying disease process and concurrent medical issues into consideration.
Norton RD, Lenox CE, Manino P, et al. Nutritional considerations for dogs and cats with liver disease. J Am Anim Hosp Assoc 2016;52(1):1-7.
Link to abstract: http://www.ncbi.nlm.nih.gov/pubmed/26606205