The animals were slaughtered 42 days later and internal organs sampled and sent for residue analysis of moxidectin, oxfendazole and levamisole. Of the 108 samples tested, one tested positive for levamisole at above maximum residue limits.
Dave Lawrence.
Lawrence said he was blind-sided by the results.
“It’s so hard to understand from a scientific point of view. Levamisole is usually broken down and 90% excreted within 24 hours. All I’m left thinking is that perhaps when used in conjunction with the other two actives it’s metabolised in a different way by the deer.”
He took a duplicate sample and tested it but the results were the same. “It is what it is and you can’t argue with it.”
Although struggling to find any positive spin-offs from the research Lawrence said the best practice treatment should still be used on weaners in late summer or autumn because there would be a three month stand-down before slaughter.
At a deer summit held late last year stakeholders agreed a deer-specific treatment needed to be developed by the industry. The process would take at least two years but the hope was the research results would support a reduced withholding period and provide a stop-gap measure.
Now the recommended triple treatment was not practically viable during spring farmers would need to discuss with their vet the next best option, Lawrence said.
“It puts the acid on even more but there are no shortcuts in coming up with a new treatment. The industry has to take charge.”
Best practice weaner drenching
The industry-recommended triple combination drench treatment for internal parasites in deer is:
- Cydectin or Exodus injection at cattle-sheep dose rate of 1ml per 50kg liveweight, and
- Oxfen C Plus and Oxfen C mixed – as required – in equal parts and given at a dose rate of 1ml per 5kg.
