Question: are red maple leaves toxic to cows?
Answer: Only the red maple (Acer rubrum) and possibly closely related hybrids are known to be toxic. The toxin in red maples oxidizes hemoglobin with the formation of Heinz bodies, methemoglobinemia and subsequent hemolytic anemia. ... Fatal poisoning of ponies fed 3.0 kg of dried red maple leaves occurred in 1 to 5 days.