Veterinary Medicine - August 2008 - (Page 440)

Copper-associated hepatopathies PEER-REVIEWED retic properties of ursodiol may increase copper excretion. Ursodiol may also reduce hepatocellular injury and brosis, modulate immune responses, and prevent bile acid-induced peroxidation by acting indirectly as an antioxidant.8 The goal of glucocorticoid therapy in patients with copper-associated hepatopathy is primarily to reduce in ammation. Since prednisolone is the active metabolite of prednisone and prednisone conversion may be impaired in dogs with substantial hepatic dysfunction, we prefer to use prednisolone in patients with liver disease. Prednisone and prednisolone have a 12- to 36-hour duration of action, and alternate-day dosing is ideal.8 Chronic corticosteroid use will increase ALP and GGT activities with minimal increases in hepatocellular leakage enzyme activities (ALT, AST); these changes do not re ect ongoing in ammation from copper-associated damage. The decision to perform subsequent biopsies can be based on serial monitoring of hepatic enzyme activities. After effective chelation therapy, institute maintenance therapy to prevent copper reaccumulation. This therapy usually consists of zinc supplementation along with dietary copper restriction. Intermittent copper chelation therapy may be required to maintain normal hepatic copper concentrations in severely affected individuals. CONCLUSION Any patient with evidence of liver disease may have increased hepatic copper concentrations, either as a primary disorder or secondary to hepatocellular dysfunction and cholestasis. If a liver biopsy is performed for histologic analysis, submit a second sample for quantitative copper analysis—especially in known copper hepatopathy-associated breeds—since diagnosis and treatment may mitigate or reverse copper-associated changes. REFERENCES 1. Thornburg LP. A perspective on copper and liver disease in the dog. J Vet Diagn Invest 2000;12(2):101-110. 2. Twedt DC, Sternlieb I, Gilbertson SR. Clinical, morphologic, and chemical studies on copper toxicosis of Bedlington Terriers. J Am Vet Med Assoc 1979;175(3):269-275. 3. van De Sluis B, Rothuizen J, Pearson PL, et al. Identi cation of a new copper metabolism gene by positional cloning in a purebred dog population. Hum Mol Genet 2002;11(2):165-173. 4. Spee B, Arends B, van den Ingh TS, et al. Copper metabolism and oxidative stress in chronic in ammatory and cholestatic liver diseases in dogs. J Vet Intern Med 2006;20(5):1085-1092. 5. Rolfe DS, Twedt DC. Copper-associated hepatopathies in dogs. Vet Clin North Am Small Anim Pract 1995;25(2):399-417. 6. Guilford WG, Strombeck DR. In: Guilford WG, Center SA, Strombeck DR, et al., eds. Strombeck’s small animal gastroenterology. 3rd ed. Philadelphia, Pa: WB Saunders Co, 1996;xiii,978. 7. Mandigers PJ, van den Ingh TS, Bode P, et al. Improvement in liver pathology after 4 months of D-penicillamine in 5 doberman pinschers with subclinical hepatitis. J Vet Intern Med 2005;19(1):40-43. 8. Sartor LL, Trepanier LA. Rational pharmacologic therapy of hepatobiliary disease in dogs and cats. Compend Contin Educ Pract Vet 2003;25:432-447. 9. Seguin MA, Bunch SE. Iatrogenic copper de ciency associated with long-term copper chelation for treatment of copper storage disease in a Bedlington Terrier. J Am Vet Med Assoc 2001;218(10):1593-1597, 1580. 10. Plumb DC. Plumb’s veterinary drug handbook. 5th ed. Ames, Iowa: Blackwell Publishing, 2005;929. SAMe and vitamin E S-adenosylmethionine (SAMe), a precursor of the antioxidant glutathione, is used as an antioxidant in liver disease. Also, it is recommended to help combat the oxidative effects of copper in copper-associated hepatopathy.8 Vitamin E is a potent antioxidant commonly used in treating liver disease, particularly copper-associated hepatopathies. Vitamin E is depleted in people with copper storage (Wilson’s) disease, and its concentrations are decreased in chronic cholestasis.8 Advise owners to avoid giving their dogs seleniumcontaining preparations because of possible selenium toxicosis. MONITORING AND MAINTENANCE THERAPY Follow-up liver biopsies with copper quanti cation are required to determine ef cacy and duration of chelation therapy. No consensus has been established about when it is appropriate to perform follow-up biopsies in these patients. In our experience, repeating the biopsy after 12 months of chelation therapy is helpful. EXTRAS See for information on hepatic biopsy in dogs. 440 August 2008 VETERINARY MEDICINE http://www.comfortis4dogs.com http://www.vetstreamcanis.com/ACI/August08/VMD1/teq00181.asp http://www.comfortis4dogs.com

Table of Contents Feed for the Digital Edition of Veterinary Medicine - August 2008

Veterinary Medicine - August 2008 Contents Editors' Note Leading Off ClinQuiz Idea Exchange Practical Matters Diagnosing and Treating Canine Copper-Associated Hepatopathies Canine and Feline Demodicosis CE Form Advertiser Index Product Preview Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - August 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.