- Plants are tall (up to 2 meters) with coarse dull green leaves and a terminal inflorescence of green to greenish-yellow florets. Seeds are dark brown to purle black, plump, shiny and 0.3 centimeters long.
- Geographic Range
- Sorghum species grow throughout the temperate regions of North America and are readily adapted to the dry hot conditions of the area south of the Great Plains to Texas. Sorghums are valuable crop plants (Sudan grass, milo) and weeds (Johnson grass).
- Toxic Principle
- in addition to occasionally accumulating nitrates and cyanide, Sorghums contain other toxins. The toxin believed responsible for neurotoxicity is b-cyanoalanine. Cyanogenic glycosides have also been suspected as possible neurotoxicants.
- toxicosis is associated with grazing of foliage, not with consumption of the seeds. Some forage sorghums contain a warning label against grazing by horses. Equine sorghum cystitis – ataxia syndrome is associated with grazing by horses.
- Clinical signs
- urinary incontinence and dribbling of urine are common in both mares and males, predisposing the horse to cystitis in the prolonged presence of clinical signs and urine stasis. In mares, periodic opening and closing of the vulva occurs as well. Urinary irritation may contribute to the appearance that mares are in estrus. Horses develop posterior ataxia and incoordination after grazing for several days on rapidly growing Sorghum forages. Forced exercise may cause affected horses to stumble or drop the ground momentarily.
- Laboratory diagnosis
- epithelial cells, bacteria and inflammatory cells may be present in urine sediment.
- inflammatory cystitis, pyelonephritis and axonal degeneration of spinal cord neurons.
- Remove from pasture
- Treat cystitis with antibiotics
- Unlikely recovery if ataxia present (due to irreversible nerve damage)
Read more in the Poisonous Plants of Pennsylvania Publication