Halogeton was introduced from Asia, and has become established in the arid, alkaline soils or clays of the western states, especially in flood plains, along rivers and roadsides.
Sheep, cattle especially. all livestock are susceptable.
Halogeton contains 30-40% soluble sodium oxalates on a dry matter basis. Poisoning in sheep occurs when 0.3-0.5% the animal's body weight of plant is consumed over a short period. In animals not adapted to eating Halogeton, the toxic dose is about one third to one quarter of that needed to induce poisoning in adapted animals.
An annual, many-branched herb with branches spreading horizontally before curving upwards as high as 50 cm. Seedlings are usually prostrate with four main branches in the form of a cross. Mature plants have red colored stems with succulent blue-green leaves terminating in a solitary hair. The small, inconspicuous flowers appear in the leaf axil. The fruit are bracted and often mistaken for the flowers. The single seed is surrounded by 5 reddish to yellow-green bracts.
Muscle tremors, tetany, weakness, reluctance to move, depression, and recumbency resulting from hypocalcemia and hypomagnesemia. Coma and death may result within 12 hours. Animals that survive the acute effects of oxalate poisoning frequently develop kidney failure.
Calcium gluconate, magnesium sulfate, glucose, and a balanced electrolyte solution can be given intravenously to maintain kidney perfusion, and treat the effects of the low blood calcium. Giving limewater [Ca(OH)2] orally will help to prevent absorption of further soluble oxalate from the rumen. The prognosis is usually very poor because of the severe kidney damage that results.
Animals that survive the acute effects of oxalate poisoning frequently develop kidney failure. Insoluble calcium oxalate filtered by the kidneys causes severe damage to the kidney tubules. Animals die from renal failure.
Sudden deaths, or weak,
Factors that predispose an animal to oxalate intoxication include the amount and rate at which the oxalate plant is eaten, the quantity of other feed diluting the oxalate in the rumen, and prior adaptation of rumen microflora to oxalates. Ruminants allowed to graze small quantities of oxalate containing plants are able to increase their tolerance for oxalate 30% or more over a few days. Sheep and cattle adapted to oxalate can make good use of range forages containing oxalate that would otherwise be toxic. Oxalate poisoning most often occurs when unadapted sheep or cattle are allowed to graze large amounts of Halogeton or Sarcobatus as they pass through, or are pastured overnight on range land containing large stands of these plants.
Supplementary dicalcium phosphate in diet prior to and during high risk periods may help to reduce risks of poisoning.
When it comes to controlling Halogeton with herbicides it is important to check with your county weed extension specialist to find out what herbicides are permissible and best for the area.
The herbicide 2-4D with a surfactant added and applied according to label directions when the plant is in active growth in the early spring is effective in controlling Halogeton.
Halogeton (Halogeton glomeratus) plant.
Halogeton showing single hair at leaf tip.
Mature plant in partial bloom