If you keep your horses in stalls for any length of time, you may use wood shavings as bedding to absorb moisture, ease pressure on their legs and feet and offer them a clean and comfortable place to lie down. Most commercially packaged shavings are prepared for safe use, but the informed horse owner should be aware of what types of wood are or could be detrimental to your horse's health and well-being.
There is little disagreement among knowledgeable horse owners and professionals on the dangers of black walnut, and it is backed up by research. The risk of black walnut to horses is particularly acute, as researchers believe that the mere presence of the horses' feet in the black walnut bedding can lead to toxicity. Horse trainer and breeder Laura Whitfield of Poseidon Sport Horses in Hutto, Texas, says that there is some recent and ongoing research that is testing the entire validity of past research claims, but, she asks, "Why would you chance it?"
Horse farrier Shelley Winston of Dripping Springs, Texas, says that while cedar smells great to horse owners and is useful for household purposes, "it is poisonous to horses." In particular, the tannic acid present in cedar may cause allergic reactions or serious digestion problems. Some horses may have no sensitivity to cedar, but Winston advises you check the contents of your shavings before using, particularly if they are coming from a new or unknown source.
Any chemically treated substance can cause issues with horses, particularly if it is ingested or inhaled, according to Tom Tower, owner of One Iron Horse Farm in Dripping Springs, Texas. "This is particularly true if your horse spends a large amount of time in his stall and the barn has limited ventilation," warns Tower. Many large boarding or training facilities, or horse owners with multiple horses, may purchase their shavings in bulk from sawmills or other construction facilities. This is dangerous, says Tower, because most wood used in construction is treated. The other danger is a lack of quality control on the type of wood in those shavings.
Some horse owners like shavings that are a finer consistency for less waste when cleaning stalls. However, if the consistency is too fine, your horse could experience respiratory issues from repeated inhalation or ingestion.The risk increases if your barn is fairly open to the outside, or is exposed to frequent wind. The shavings can also blow into your horse's drinking water.