District Veterinary Officer Jeff Cave said when an animal is poisoned by nitrite, the ability of its blood to transport oxygen is reduced.
“As a result, an affected animal will have difficulty breathing, followed by becoming weak and staggery before collapsing and dying. If clinical signs are noticed early enough, veterinary treatment is possible,” Dr Cave said.
“Many weeds, crops and pasture plants have been associated with nitrite poisoning.”
“Capeweed, variegated thistle, marshmallow and pigweed are well known accumulators, along with many of the major crop plants including maize, rape, soybean, linseed, sorghum, millet, wheat, oats and barley have also been associated with nitrite poisoning.”
The factors that typically lead to nitrite poisoning include:
- rapid uptake of soil nitrate following rain after a prolonged dry spell
- moisture stress and low temperatures
- the use of nitrogenous fertilisers
- spraying with hormone-type herbicides such as 2,4-D
- grazing hungry stock on forages that are potentially dangerous.
“Furthermore, cattle and sheep can tolerate a certain amount of nitrite. A way of preventing nitrite poisoning is to ensure cattle and sheep are not overly hungry when introduced to a new feed, so their intake of nitrite is moderated to a tolerable level.”
“If nitrite poisoning is suspected, animals should be removed without delay from the suspect paddock and placed onto feed containing less toxic herbage,” Dr Cave said.
For further advice please contact your local veterinarian or Agriculture Victoria veterinary or animal health officer, or in NSW your Local Land Services.