Laurel Poisoning in Horses

By PetMD Editorial on Sep. 4, 2009

This Common Shrub is Highly Fatal to Horses

The laurel plant is a common shrub, mainly found in the Southeastern United Sates in open wooded areas, mountainous areas, and in both dry and wet land areas. All types of laurel are toxic to horses, with the severity of the reaction based on the health of the horse. The age and size of the horse are also components of the type of reaction that can be experienced. Hydrogen cyanide, the active ingredient that is found in the laurel, can be fatal to even the healthiest of horses and so cases of poisoning should be diagnosed as soon as possible to ensure survival of the horse. Prompt care is essential for a full recovery.

The leaves of the laurel are thick and a bit rubbery in texture, with clusters of white to pink flowers when in bloom. The taste of the plant is bitter, so instances of poisoning are relatively few. Horses typically will not eat from this plant unless there is a lack of other grasses to graze on, or the laurel is growing amongst other grazing plants.

Symptoms and Types

  • Quickened heart beat
  • Slowed heart beat
  • Difficulty breathing
  • Wheezing
  • Vomiting
  • Weakness - Difficulty performing natural amounts of work
  • Loss of condition
  • Collapse
  • Cardiac failure
  • Respiratory failure
  • Death


Laurel toxicity occurs following ingestion of leaves, stems, or flowers from the laurel shrub. Hydrogen cyanide poisoning, the toxic ingredient, combines with hemoglobin and oxygen to prevents oxygen from being distributed to the cells. Systemic poisoning often results in poisoning of the heart muscle.


It can be difficult to figure out what is wrong with your horse during the earliest stages of laurel poisoning. The diagnosis of this condition often comes post-mortem, which is why it is so important to ensure that horses do not have access to laurel bushes or anything that may have parts of laurel bush in them. A veterinarian should always be consulted when laurel poisoning or any type of poisoning is suspected in your horse.



Since laurel poisoning affects a horse in much different ways than other types of plant poisoning the methods of treatment are often much different. Artificial respiration is the first and most common step for treatment of this condition; a high concentration of oxygen is the best method for increasing the chances of survival.

Living and Management

The unfortunate reality of laurel poisoning is that many horses do not survive it. When the diagnosis is made most horses that have ingested laurel bushes are either recovering from the effects of the toxicity or have passed away from it. An ounce of prevention is worth a pound of treatment. Before you place your horse on land, you must ensure that all toxic plants, including laurel, have been removed entirely. Frequent property checks for new plant growth, and making sure that your horse is well fed and has plenty of healthy grass to graze on are also important for ensuring that your horse will not feel the need to graze on toxic plants.

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