Cape Town - The SPCA has warned livestock farmers about the dangers of animals eating toxic grain siftings (or sweepings) after three horses died in Darling recently.
Swartland and West Coast SPCA inspector Stephanie Fortuin was called out to a farmer’s smallholding in Darling.
She found four of nine horses to be very ill.
“They were seemingly poisoned. The vet, also present, had to euthanise two of the horses; one recovered after symptomatic treatment. The fourth horse died before there could be any intervention,” she said.
Fortuin decided to load the fourth horse on to her bakkie and drive it to the state vet in Elsenburg, Stellenbosch, for an autopsy.
The report declared the cause of death as phosphine poisoning.
“We now understand that aluminium phosphide is used as a fumigant in grain silos for the control of insects such as grain weevils.
“Small remnants of aluminium phosphide are sifted out of the main body of grain and become concentrated in the siftings and may reach toxic levels,” the SPCA said.
In animals, phosphine primarily affects the central nervous system, causing hypersensitivity, convulsions and the possibility of slipping into a coma.
The report to the SPCA on phosphine poisoning by the state vet said: “It would appear that silo operators and livestock farmers are unaware of the fact that siftings of fumigated grain may still be toxic for 14 days or even longer, after being released from the silo and aerated.
“However, once fumigated grain is aerated, which liberates trapped phosphine PH3gas, it is completely safe for human or animal consumption.”
The danger of using grain siftings from fumigated cereals should be clearly stated on the instructions and package inserts accompanying the various fumigation products.
There should also be a warning that grain siftings should be moistened with water and allowed to dry out before it can be safely used as animal feed, the vet’s report said.
The SPCA said this information should be made available to all grain handling and storing businesses in South Africa, so that they could warn clients buying siftings.
It should also be emphasised during the training of silo operators.