Blackthorn (Prunus spinosa) is a deciduous flowering shrub or small tree that is known for its sharp spines or thorns. It belongs to the same genus (Prunus) as cherry, plum, peach, apricot and almond trees. Blackthorn is most commonly found in hedgerows and thickets, forming dense stands of thorns.
Blackthorn flowers early, between March and April, and the seeds ripen in October. It produces five-petaled white flowers and dark round bluish purple berries. Each berry contains a large stone with a single seed inside.
Blackthorn Toxic Components
Being a member of the Prunus family, Blackthorn contains varying amounts of cyanogenic glycosides---which convert to cyanide (prussic acid) when plant parts are chewed, crushed, trampled, or grinded. Cyanide is a highly toxic poison, which is quickly absorbed from the gastrointestinal tract into the bloodstream. Once in the blood, it inhibits the blood cells from delivering oxygen to tissue cells causing the horse's blood to become supersaturated with oxygen and appear bright red. Depending on how much cyanide is ingested, horses may develop signs of acute poisoning or chronic poisoning. The toxin is found predominately in the leaves and seeds of this plant.
Blackthorn is also known for causing infections and tissue reactions in horses, due its sharp thorns. The resulting condition is referred to medically as blackthorn plant thorn synovitis.
- Acute Onset Synovitis
- Thorn Fragments And Debris Evident On Lower Legs
- Rapid Breathing
- Bright Red Mucous Membranes
- Respiratory Failure
- Hindlimb Incoordination
- Urinary Incontinence
- Weight Loss
- Low Blood Pressure
- Royal Botanical Gardens Prunus spinosa (blackthorn) Kew. 2016.
- NM Ashton, J Doles Plant Thorn Synovitis Caused by Prunus Spinosa (Blackthorn) Penetration in 35 Horses Equine Veterinary Journal. 2015.
- Mitchell, J. C.; Rook, A. J. Botanical Dermatology. Plants and plant products injurious to the skin. Greengrass. Vancouver, 787 pp. 1979.
- Perkins, K. D.; Payne, W. W. Guide to the poisonous and irritant plants of Florida. Florida Ext Serv Circ, #441 89 pp . 1978.
- Hardin, J. W. Poisonous plants of North Carolina. North Carolina Agric Exp Sta Bull, #414(May), 128 pp . 1961.