Onion

Verdict

Onions are significantly more dangerous to cats than to dogs. Cats lack sufficient levels of the enzyme glucose-6-phosphate dehydrogenase (G6PD), making their red blood cells highly vulnerable to oxidative damage from thiosulfates and organosulfur compounds found in onions. This causes Heinz body anemia — a condition where red blood cells are destroyed faster than they can be replaced. Cats are affected by much smaller doses relative to body weight than dogs. Even a small amount of onion in any form — raw, cooked, dehydrated, powdered, or in juice — can trigger a life-threatening crisis.

Symptoms to watch for

• • pale or white gums
• • lethargy and weakness
• • rapid breathing or panting
• • vomiting and diarrhea
• • reduced appetite
• • reddish-brown urine (hemoglobinuria)
• • elevated heart rate