Yew

Symptoms reported in cats

Most serious first.

1. 1
   Cardiac abnormalities: rapid heartbeat progressing to bradycardia and arrhythmias Rapid · This is the most dangerous and primary effect of Yew poisoning, caused by the highly toxic taxine alkaloids12. It profoundly disrupts the heart's function, leading quickly to cardiac standstill and death from heart failure.
2. 2
   Difficulty breathing (dyspnea) and rapid breathing Rapid · Severe respiratory distress and tachypnea accompany the sudden, systemic cardiovascular collapse and are exacerbated by the toxic alkaloids, volatile oils, and cyanide found in the plant.
3. 3
   Sudden weakness, drowsiness, and collapse Rapid · A cat will often present with extreme lethargy and sudden collapse as a direct result of the plummeting blood pressure and failing heart function.
4. 4
   Trembling, nervousness, and ataxia (loss of coordination) Rapid. · In addition to its cardiac effects, compounds in the Yew plant like ephedrine cause extreme neurological stimulation, leading to noticeable tremors and an inability to walk normally.
5. 5
   Vomiting and upset stomach Rapid · While gastrointestinal distress is a notable symptom of Yew ingestion, it is rapidly overshadowed by the life-threatening cardiac and neurological emergencies that follow.

Important notes

Yew (Taxus spp.) is an extremely poisonous plant that is highly lethal to cats, dogs, livestock, and humans. All parts of the plant are toxic, including the needles, stems, and seeds. The only part that is not poisonous is the soft, red flesh of the berry, but the seed within it is one of the most toxic parts. The plant's primary toxins are called taxine alkaloids. These are potent, fast-acting cardiotoxins that disrupt the function of the heart's sodium and calcium channels. Ingestion causes severe cardiac arrhythmias (irregular heartbeat), which quickly leads to cardiac arrest and death. Even a very small amount, such as chewing on a few needles, can be fatal. Symptoms of Yew poisoning are sudden and severe, often leading to death with little to no warning. They can include trembling, difficulty breathing, weakness, collapse, and a slowed heart rate. Due to the rapid and deadly nature of the toxins, there is often no time for veterinary treatment to succeed. Any suspected ingestion of a Yew plant is a dire medical emergency. Please contact your veterinarian or an emergency animal hospital immediately.

• Toxic compounds: taxine A and taxine B; present in all plant parts except the berry flesh; the brown seed inside the red berry is also toxic
• Mechanism: taxines block calcium and sodium channels in the heart, causing profound cardiac depression, arrhythmias, and cardiac standstill
• Symptoms: sudden weakness, collapse, trembling, difficulty breathing, slow heart rate, heart block; death can occur with little warning
• Toxicity is extremely rapid — treatment window is very narrow; even a few needles consumed can be lethal
• Any suspected Yew ingestion is an immediate veterinary emergency — do not wait for any symptoms