Red Maple Leaves

• You may have many different types of red leaf-producing trees on your property, but red maple leaves can be determined by examining the undersides. The bottom of the leaves tend to produce a whitish sheen. The leaves are green during the spring and summer, but have red stems year-round. Also, a young tree will have pale gray-colored bark and an older tree will have darker bark. These trees can be found anywhere in the United States, but especially from the Atlantic coast to eastern Texas.
  
  

The Leaves

• The problem with the leaves of the red maple exists only when the leaves have detached from the tree before the tree releases them naturally as part of fall shedding. This usually happens after severe winds have blown the leaves off or if you have been pruning the leaves. The horse only has to eat between one or two pounds to die from the toxin, which kills red blood cells. This results in kidney damage. Green leaves and leaves that have fallen off in the fall are usually safe.
  
  

Signs

• It may take four or five days for your horse to begin showing symptoms. Your horse may become lethargic and lose his appetite, and his urine may become darkly-colored. If you check his gums, the color will be pale or maybe yellow. He may also have an increased heart and respiratory rate, and be dehydrated.
  
  

Prevention

• Since removing all trees may not be possible, as neighbors may have red maple trees on their properties as well, try moving your fence lines so that access to the trees is lessened. Until then, raking up and disposing of the leaves is your best bet, or you can take your horses off the exposed pasture until 30 days after the leaves have fallen. After 30 days the toxin should not be present in the leaves.
  
  

Treatment

• If you suspect red maple toxicity in your horse, call your veterinarian immediately, who may recommend that you send your horse to a veterinary hospital or clinic. Whether treated at home or at the clinic, your horse will need lots of intravenous fluids and antioxidants. The treating veterinarian may even find that blood transfusions are necessary. About 50 to 75 percent of affected horses that do not receive veterinary care die from the toxicity, according to the Equus magazine article "A Horsekeeper's Plan for All Seasons" by Eliza McGraw.