Yew (Taxus) toxicity in pets

Taxines are antagonists of calcium channels, particularly in the heart. Taxine B is more potent, has a negative inotropic effect, and reduces heart rate (HR). It is also associated with AV conduction delay.

• Peracute: Bradycardia and cardiovascular collapse can occur due to the disruption of cardiovascular function, characterized by arterial vasodilation and hypotension. This condition can be lethal.

• Subacute: Symptoms may include bradycardia, ventricular fibrillation, arrhythmias, dyspnea, hyperthermia, ataxia, tremors, behavioral changes, mydriasis, recumbency, seizures, and collapse. This condition can also be lethal.

• Gastrointestinal: Gastrointestinal symptoms may occur as a secondary effect of the volatile oil irritants, leading to vomiting and diarrhea.

Emesis: Induction is recommended if ingestion was witnessed.

Gastric Lavage: Followed by activated charcoal (1-3 g/kg with a cathartic).

IV Fluids: Administer to maintain blood pressure and cardiovascular perfusion.

Antiarrhythmics:

• Lidocaine:

Dogs: 2–4 mg/kg IV as a single dose, followed by a continuous rate infusion (CRI) of 25–200 μg/kg/min.

Cats: 0.25–0.5 mg/kg slow IV, followed by a CRI of 10–20 μg/kg/min (not recommended for cats).

• Procainamide:

Dogs: 2–4 mg/kg IV over 3–5 minutes (up to a 20 mg/kg IV bolus), followed by a CRI of 20–50 μg/kg/min.

For Bradycardia:

• Atropine: 0.02–0.04 mg/kg IV or IM.

For Seizures:

• Diazepam: 0.25–0.5 mg/kg IV.

• Midazolam: 0.1–0.5 mg/kg IV.

Antiemetics:

• Maropitant: 1 mg/kg SC every 24 hours.

• Ondansetron: 0.5–1 mg/kg IV every 12 hours.

GI Protectants: As needed (e.g., IPP, sucralfate).

If you suspect your pet has ingested yew, contact a veterinarian immediately. Prompt treatment is essential to mitigate the effects of the toxin and ensure the best possible outcome for your pet.