Recently, some horses have died or become sick with the cause pointing to ingestion of persimmons. Common persimmon is a tree that produces a fruit. The persimmon tree is hardy and adaptable to a wide range of soils and climates. Several cultivars have been selected primarily for fruit color, taste, size and early maturation; several are seedless.
The common persimmon tree is often seen growing wild as thickets in open fields and pastures. This species flowers in March-June and fruits in September-November. Fruit may be produced by 10 year old trees but optimum fruit-bearing age is 25-50 years. Good fruit crops are borne every 2 years. The fruit is a berry 1-2 inches wide, greenish to yellowish with highly astringent pulp before ripening, turning yellowish- orange to reddish-orange and sweet in the fall, each fruit with 1-8 flat seeds.
Very little is documented concerning persimmon fruit and potential problems with consumption in livestock or horses. In A Guide to Plant Poisoning of Animals in North America by Knight and Walter, persimmon fruit is listed as one of five "plants that cause rumen impaction and intestinal obstruction". The principal toxin associated with persimmon fruits is water soluble tannins.
Persimmon fruit when consumed by the horse and due to the water soluble tannins precipitate in the stomach to form a sticky coagulum of fruit skin, pulp, seeds and gastric protein that becomes a solid mass or phytobezoar. Once formed, the phytobezoar is abrasive and can lead to ulcers and even rupture of the stomach in horses that have eaten large quantities of ripe persimmon fruits. A large quantity is defined as 33 to 35 fruits.
Severe colic results when impaction of the stomach occurs or when the phytobezoar causes an intestinal obstruction. Intermittent colic and weight loss are non-specific signs of persimmon ingestion in the horse. Even after the phytobezoar has formed the diagnosis can be difficult unless it is suspected that horses in the fall of the year had access to the fruits, and the persimmon seeds can be visualized in the stomach using an endoscope.
Treatment for phytobezoar is aimed at softening the mass with mineral oil and dioctyl sodium succinate to allow its passage through the gastrointestinal tract.
Obviously, surgery may be required when treatment does not work and colic is very severe. The bottom line is Persimmon trees should not be planted where horses can have access to the fruits. If horses have access to wild persimmons, caution should be taken in the fall of the year realizing that certain years more fruit is produced and available for consumption.
Source: Dr. Gary Heusner, Extension Animal Scientist