Survival and Prognostic Indicators for Cycad Intoxication in Dogs

Abstract

Background: Cycad palms are commonly used in landscaping and ingestion by dogs can cause disease or death. Objectives: Determine the morbidity and case fatality of cycad palm toxicosis in dogs from Louisiana, and examine putative prognostic factors.Animals: Thirty-four client-owned dogs with confirmed cycad palm toxicosis between 2003 and 2010. Methods: Retrospective cohort study. Search of all medical records for animals with cycad palm toxicosis.Results: Seventeen of 34 (50%) dogs died or were euthanized as a direct consequence of cycad intoxication. There were no differences in presenting signs and physical examination findings between survivors and nonsurvivors. Nonsurvivors had higher serum alanine transaminase activity (median 196 U/L; range 16-4,123 versus 113.5; 48-1,530) and total bilirubin concentration (0.5 mg/dL; 0.1-6.2 versus 0.25; 0-1.7) upon presentation, and their initial serum concentrations of albumin (2.9 g/dL; 1.4-4.1 versus 3.3; 2.2-3.9) were lower than those of survivors. Nadir serum albumin concentration was also lower in nonsurvivors (1.9; 1.4-3.7 versus 3.2; 1.8-3.5). A higher proportion of nonsurvivors had prolonged coagulation times, prothrombin time. and partial thromboplastin time. In a multivariate model, administration of charcoal at initial presentation was associated with longer survival (heart rate [HR] 0.019, 95% CI 0.001-0.644), while high serum aspartate aminotransferase activity was a negative prognostic factor (HR 118.2,826).Conclusions and Clinical Importance: Cycad intoxication is associated with a higher case fatality than previously published. Several laboratory parameters might help differentiating potential nonsurvivors from survivors. Administration of charcoal as part of the emergency treatment appears to have a protective effect.

Retrospective evaluation of acute liver failure in dogs (1995–2012): 49 cases

“…If toxin exposure is suspected, treatment with activated charcoal is indicated. In addition, for toxins that undergo enterohepatic circulation, the use of bile acid resins (ie, cholestyramine) may help to bind and eliminate the toxin …”

“…2 In the veterinary literature, isolated case series of dogs with acute hepatic disease related to toxins, drugs, neoplasia, or infection have been reported. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Although these reports include dogs that fit the criteria for ALF, no comprehensive study reporting solely on dogs with ALF exists. A single study of dogs with acute hepatitis has been reported, but based on clinical findings, this population of dogs did not fit the criteria for ALF.…”

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

“…In the case of phenobarbital, toxicity may be direct or related to altered metabolism of other xenobiotics. Several other drugs or toxins including carprofen, oxidbendazole, amiodarone, aflatoxin, and cycasin may lead to CH although they more commonly cause acute hepatic injury . In humans, it is estimated that herbal and dietary supplements are responsible for up to 18% of drug‐induced liver injury (refer to https://livertox.nih.gov/).…”

“…Several other drugs or toxins including carprofen, oxidbendazole, amiodarone, aflatoxin, and cycasin may lead to CH although they more commonly cause acute hepatic injury. 89,[97][98][99][100][101][102][103][104][105][106] In humans, it is estimated that herbal and dietary supplements are responsible for up to 18% of drug-induced liver injury (refer to https://livertox.nih.gov/). [107][108][109][110][111] There are several anecdotal but poorly documented reports of liver injury in dogs given herbals or nutritional supplements.…”

Approach to Drug Overdose

“…8 With hepatotoxicants, the routine use of SAMe (18 mg/kg PO for 2 to 4 weeks) can be considered and adjusted based on routine monitoring of liver enzymes. 4,6-8 SAMe acts as a methyl donor and generates sulfur-containing compounds that are important for conjugation reactions used in detoxification and as a precursor to glutathione.…”