Due to ingestion of fruit from the flowering shrub/small tree, Karwinskia humboldtiana (aka Coyotillio or Humboldt Coyotillo) in the buckthorn family (Rhamnaceae)
Geographic Distribution: Karwinskia humboldtiana plant is found in the southwestern US and Mexico
Prevalence in Humans: children are the most commonly affected
Prevalence in Animals: cattle and goats are the most commonly affected
Cattle are the most susceptible
In animals, disease is called “Limberleg”: presents with incoordination and ataxia
Physiology
Exposure: ingestion of buckthorn fruit (Karwinskia humboldtiana)
Severity of toxicity is proportionate to the amount of fruit ingested
Intoxication with buckthorn (Karwinskia humboldtiana): report of three siblings. Pediatr Dev Pathol. 2007 Jan-Feb;10(1):66-8 [MEDLINE]
Karwinskia humboldtiana (buckthorn) fruit causes central nervous system damage during chronic intoxication in the rat. Toxicon. 2009 May;53(6):645-51 [MEDLINE]