Lab tests prove paraquat poisoning

Tests confirm two dogs died from ingesting herbicide

Laboratory tests have confirmed that two dogs poisoned last month died from ingesting the herbicide paraquat.

Brenda Bush from Island Veterinary Services said tissue sample were taken from the lungs of two of several dogs that had died from suspected paraquat poisoning and sent to the University of Wyoming laboratory in the US.

These may be among some of the last test the lab will do for paraquat poisoning because ‘they are no longer seeing any cases in the USA; it’s simply not being used anymore,’ Dr. Bush said.

‘They’re thinking of phasing it out because the only samples they’re getting now is from overseas,’ she added.

She said animals that ingested the poison sometimes took several days to die. ‘Paraquat poisoning leads to a slow, painful death that can take days,’ she said.

According to the US Centres for Disease Control and Prevention, paraquat is classified as ‘restricted use’ and can only be used by people who are licensed applicators.

The form of the herbicide marketed in the US has a blue dye, a sharp odour and an added agent to cause vomiting if ingested.

Dr. Bush said paraquat was being replaced in the US by less toxic chemicals.

‘The newer herbicide chemicals are animal-friendly,’ she said, adding that other herbicides on the market that could be used maliciously to poison animals caused more immediate death ‘and are deemed more humane since paraquat causes a slow agonising death’.

The lab tested samples from Amarillo who died after being walked on a beach in South Sound and found gross changes in lung tissue consistent with paraquat poisoning.

‘His clinical signs and clinical course were identical to the other dogs treated and died from the South Sound beach area,’ Ms Bush said.

The laboratory found detectable levels of paraquat in the lungs of the second dog, Lassie, from East End,’ the vet said.

Dr. Bush said she had repeatedly tried over the years to convince the government to ban paraquat, even organising a petition in the mid-1990s to ban the poison after so many dogs died from ingesting it.

She said that the poisoning appeared to happen in spates. In the last six months, at least 10 dogs have been treated at her veterinary clinic for paraquat poisoning which is almost always fatal.

Island Veterinary Services paid for the lab tests, which cost $100 each, because she said most owners find the cost of a post-mortem toxicology examination prohibitive.

The Department of Agriculture stocks paraquat but says it only supplies it to bona-fide farmers and it is not sold to the general public.

However, in an earlier interview with the Caymanian Compass, the assistant director of agriculture Brian Crichlow said: ‘The department can only attempt to control the sale and use of the pesticide products that it brings in and sells.

‘The DoA is not the sole importer or retailer of agricultural chemicals, which despite the efforts of the Department of Agriculture, still remain largely unregulated under existing laws.’

Paraquat was first produced for commercial purposes in 1961 and worldwide is still one of the most commonly used herbicides.