First Walk is on Us!

✓ GPS tracked walks
✓ Activity reports
✓ On-demand walkers
Book FREE Walk

Jump to Section

What is Mayapple Poisoning?

A perennial of the Barberry family, mayapple (also known as Indian Apple) has umbrella-shaped leaves that are about eight inches wide. Some plants have a single leaf and those do not flower. Others have two leaves and they will develop one flower in the axil of the leaf stalks. The flower, which blooms in April to May, will have six or more white petals and will be about one and a half to two inches in width. A green egg-shaped fruit will eventually replace the flower and by the middle of summer the mayapple plant will dry up. The plant is commonly used for ground cover in many parts of the United States and grows in damp areas like pastures and meadows; it is also often found along roads in the Midwest.

The glycoside podophyllotoxin in contained in mayapple and is toxic to horses should they ingest all or a portion of the plant. The fruit is also toxic until it has ripened. The mayapple plant tastes bitter and will immediately cause irritation. These factors will typically ensure that too much of the plant is not eaten. A horse will usually avoid eating mayapple unless they are lacking in other sources of food.

A perennial of the Barberry family containing the glycoside podophyllotoxin, the mayapple plant and its unripened fruit are toxic in horses.

Book First Walk Free!

Symptoms of Mayapple Poisoning in Horses

Should your horse experience mayapple poisoning, you may notice the following symptoms:

  • Diarrhea
  • Abdominal pain
  • Colic
  • Excessive drooling
  • Panting
  • Dermatitis
  • Swelling of the mouth
  • Appearing tired
  • Showing excessive energy
  • In rare cases, coma

Types 

The mayapple plant is known by a number of other names; these include:

  • American mandrake
  • Raccoon berry
  • Wild lemon
  • Hog apple
  • Indian apple
  • Devil’s apple
  • Umbrella plant
  • Ground lemon
  • Wild jalap
  • Umbrella leaf

Causes of Mayapple Poisoning in Horses

All parts of the mayapple plant have podophyllin, a glycoside that is toxic to horses. It will cause irritation in live tissue and works as a laxative. Podophyllin will also interfere with the normal division of cells and get in the way of cell growth and multiplication. 

Should the toxin make its way from your horse’s mouth to another part of his face, it may cause swelling and irritation as a result of the plant’s irritant properties.

Diagnosis of Mayapple Poisoning in Horses

When noticing concerning symptoms in your horse you will want to contact your veterinarian. Should you have observed your horse consuming mayapple, it is a good idea to have a sample of the plant available for the veterinarian to see as this will be helpful in his diagnosing your horse. A sample will also be useful even if you have not noticed your horse ingest the plant but suspect he may have.

Your veterinarian will examine your horse and ask you for information regarding the symptoms you have noticed, when you noticed them and any changes that you have observed. Your veterinarian may choose to conduct tests on your horse to include a blood test, biochemistry profile and urinalysis. There is no specific test available for mayapple poisoning; the diagnosis will be based on clinical signs and a rule-out of underlying conditions that may present similarly. Blood testing and urinalysis will indicate, however, how the organs and system of your equine are reacting to the toxin. Should your horse appear to be experiencing a severe case of toxicity, more testing may be conducted to determine other issues that need to be addressed.

Treatment of Mayapple Poisoning in Horses

When looking to treat your horse for mayapple poisoning, your veterinarian will focus on providing supportive care. Eliminating the toxin from your horse’s system is an important step. Your veterinarian may administer activated charcoal to make sure that no more of the toxin is absorbed. Gastrointestinal medications may be given to help relieve the stomach discomfort that your horse is experiencing. These medications will coat the lining of your horse’s stomach to help with the inflammation that has occurred. Intravenous fluids may be administered to ensure that your horse remains hydrated. This is particularly important if he has been experiencing significant diarrhea.

Recovery of Mayapple Poisoning in Horses

Ingestion of mayapple is rarely life threatening in a horse, who will likely experience stomach and skin issues as a result of toxicity. With proper supportive care your horse will likely make a full recovery. You will want to work closely with your veterinarian and follow his recommendations to ensure the best outcome for your horse.

It is important for the health of your horse that you remove any mayapple that is present in the area where he grazes so that he won’t ingest the plant in the future.