VETgirl Q2 2020 Beat e-Newsletter










Centrolobular and mid-zonal coagulative hepatic necrosis

GI signs (vomiting, diarrhea) within 15 minutes to several hrs, CNS signs (lethargy, seizures) (48-72 hrs), liver failure (24-72 hrs)

Cycads ( Cycas spp., Macrozamia spp.) (SE, South central or tropical areas of US usually) but can be found as bonsai household plant Multivitamins, iron supplements, fertilizers, snail/slug bait

• Baseline bloodwork, PT/PTT • PCV/TS/BG/liver panel q 24 hrs x 2-3 days

↑↑ Liver enzymes (24-72 hrs)

All parts of the plant are poisonous, but seeds contain largest amount of toxin

1-2 seeds can lead to severe signs Grave prognosis once hepatoxicity seen Toxicity dependent on amount of elemental iron 20-50 mg/kg = GI signs 50-80 mg/kg = GI ulcers > 80 mg/kg = liver and other systemic effects

Sago Palm

GI signs (e.g., vomiting, hematemesis, melena, diarrhea) within 0.5-6 hrs; liver failure 12-24 hrs later With large doses can see hypovolemic shock, coagulopathy and acidosis

Fluid therapy, anti-emetics, blood work monitoring, hepatoprotectants, symptomatic and supportive care antiemetics, GI protectants/antacids, hepatoprotectants, deferoxamine (chelator), supportive care, blood work monitoring • MgOH can be given while iron is still in the GI tract • Emesis if appropriate. Activated charcoal does not bind and should not be used • Other treatment includes

↑↑ Liver enzymes; ↑↑ PT/PTT if liver necrosis

Metabolized into reactive epoxide, binds to hepatocytes Large acute exposures = hepatic necrosis; smaller chronic exposures = neoplasia Stops cellular protein synthesis in multiple organs Hepatotoxicity thought to be from inhibition of mitochondrial function When serum iron exceeds the binding capacity of transferrin and ferritin, free iron causes lipid peroxidation and damage to liver, heart and brain Iron is also caustic to the GI mucosa


Serum iron levels; chelate warranted if iron > 400 mcg/ dl)

Vomiting, anorexia, lethargy, icterus, coagulopathy

Mycotoxin (mold) found in corn, peanuts, cottonseed, rice and potatoes

↑↑ Liver enzymes; ↑↑ PT/PTT


Acute – diffuse hepatic necrosis Chronic – fatty liver

GI (e.g., anorexia, vomiting, melena, stomach ulcers), lethargy, icterus

NSAID pain medication

Fluids, anti-emetics, antacids, gastroprotectants, hepatoprotectants

↑↑ Liver enzymes

Dogs > 400 mg/kg for liver effects


Centrilobular hepatic necrosis

GI (e.g., anorexia, vomiting), lethargy, anorexia, icterus, weakness, tremors, death

Castor bean (Ricinus communis) , Precatory bean (Abrus precatorius) , Black locust ( Robinia spp. ) , Mistletoe (Phoradendron) Pennyroyal oil, melaleuca (tea tree) oil

Fluids, anti-emetics, symptomatic and supportive, hepatoprotectants

↑↑ Liver enzymes

All parts of plants are toxic. Seeds are most toxic part of Ricinus and Abrus . Seeds must be chewed to release the toxin. Usually associated with application of 100% oil to open wound, ear canal or oral ingestion

Lectins (toxalbumins)

Vomiting, lethargy, ataxia, hind limb weakness, icterus

Symptomatic and supportive (fluids, hepatoprotectants)

↑↑ Liver enzymes


Essential oils

isoniazid, ketoconazole, lomustine, methimazole, melarsomine, mitotane, sulfonamides, trazodone, zonisamide

• Discontinuation of drug • Hepatoprotectants • Symptomatic supportive care

Veterinary drugs associated with hepatotoxicity (albeit rare)

Abbreviations: AKI: acute kidney injury; CNS: central nervous system; DIC: disseminated intravascular coagulation; GI: gastrointestinal; LD: lethal dose; LES: liver enzymes; Meth: methemoglobin; NAC: N-acetylcystine; PT: prothrombin; PTT: partial thromboplastin time

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