Castration-tool ruling stings veterinarians Down Under

Painkilling system for sheep will be sold over-the-counter

Published: December 09, 2022
Photo courtesy of Senesino
The Numnuts device allows farmers to castrate lambs or dock their tails while injecting a pain-relieving dose of the local anesthetic lidocaine.

A novel device that enables farmers to castrate sheep or dock their tails while delivering a dose of anesthetic is eliciting mixed feelings in the veterinary community, amid concerns prescription-free access will take work away from practitioners in rural areas.

The device, called Numnuts, was designed in Scotland but commercially introduced first in Australia, in 2019. It was launched in New Zealand last year and is slated for launch in the United Kingdom by the end of 2024.

The product works by combining the traditional ring-based castration method, used by farmers for decades, with an injection mechanism to administer pain relief. The device is used to place a rubber ring around a lamb's testicles or tail, cutting off blood supply and eventually causing them to fall off. The user simultaneously activates a plunger that delivers to the lamb a fixed dose of local anesthetic via subcutaneous injection.

The drug delivered by the device, lidocaine, is available over-the-counter in topical form in many countries, for use in humans and other animals. Access to lidocaine in its injectable form, though, requires a prescription in places such as Australia, New Zealand, Europe and the United States. Indeed, veterinarians currently are the sole sales channel for the injectable form of lidocaine used in the Numnuts device, dubbed NumOcaine.

Now, Australia has sparked controversy by changing its rules to facilitate easier access for farmers. In a final decision issued Nov. 18, the country's Therapeutic Goods Administration (TGA) said it will make NumOcaine available over-the-counter, effective Feb. 1. The TGA also opted to allow an orally administered form of another veterinary painkiller, meloxicam, to be sold over-the-counter, too — no prescription from a veterinarian required.

Lidocaine is a fast-acting local anesthetic, while meloxicam is a longer-acting analgesic. Combining the drugs can provide immediate and lasting pain relief for castration and tail docking. The rule change in Australia primarily affects sheep, since Numnuts has been designed and approved only for sheep. The orally administered meloxicam product, called Buccalgesic, is used less commonly in calves than in lambs.

In brief

Worldwide, farmers typically aren't obliged to administer pain relief to animals undergoing various husbandry procedures, which also can include disbudding (horn removal) and mulesing, the latter involving the removal of strips of skin from a lamb's buttocks to prevent parasitic infection. However, rising public concerns about animal welfare and a recognition that comfortable animals can be less disease-prone and more productive, are inspiring more widespread use of the drugs.

The TGA's move to make them more freely available was opposed, unsuccessfully, by the Australian Veterinary Association. The organization contends that removing veterinarians from the equation will hurt animal welfare in the long run — by taking work away from rural practices already struggling with labor shortages and a spate of recent natural disasters ranging from floods to wildfires.

"Over the years, there's been a reduction in farmers using veterinarians," Dr. Susan Swaney, president of the AVA's sheep, goat and camelid special-interest group, said in an interview. "And I think farmers need to engage with their local vets to ensure they remain strong and are able to meet farmers' needs."

The AVA also is concerned about the potential for animals to be harmed by incorrect administration of the drugs, or for humans to be harmed by misusing them. As of Feb. 1, any adult will be able to walk into a rural merchandise store and purchase the products.

"Ideally, you'll be using a combination of these two drugs, but that adds complexity to the procedure," Swaney said. "Farmers will still be able to buy the applicator product and the drugs from us, and I think it would be really good for farmers to utilize that advice — to find a vet who knows what they're talking about."

Device wins government, industry backing

The origins of Numnuts date to the 1990s, when Dr. Vince Molony, a professor at the University of Edinburgh's school of veterinary medicine, started investigating the use of pain relief during tail docking and castration. A prototype delivery system was manufactured in the 1990s but was deemed too costly for commercial release.

Work on Numnuts commenced in 2009, when the Scottish research institute Moredun Research and the engineering firm 4c Design teamed up to have another go. Their joint venture, called Senesino, soon attracted funding support Down Under — where sheep outnumber people three-to-one — from industry bodies Meat & Livestock Australia and Australian Wool Innovation. The Australian federal government helped trial the product via its Commonwealth Scientific and Industrial Research Organisation (CSIRO).

The inventors of Numnuts set out to develop a safe and fast way for farmers to improve animal welfare, according to Dougal Deans, Senesino's general manager for Australia and New Zealand. The ultra-remote location of some Australian farms, combined with a shortage of veterinarians in many rural communities, is hindering accessibility, he said.

"For some customers in Australia, the closest vet might be three hours away," Deans said in an interview. "Plus the vet — while they're a very, very useful resource — charges a prescription fee and a consultancy fee that also might act as a barrier for farmers."

The lidocaine used in Numnuts, Deans said, is safe to buy without a prescription because it is contained in a tamper-resistant cartridge and delivered in a fixed dose that's appropriate for the patient.

The TGA, in justifying its decision to relax the rules, noted that Numnuts is used for husbandry procedures "that are typically performed by farmers or contractors, and do not require consultation with a veterinarian." The product's design "sufficiently mitigates" the risk of misuse, the TGA added. Similarly, the regulator said allowing the orally administered meloxicam product to be sold over-the-counter "will enable reasonable access to a relatively safe medication."

Farmers appear upbeat about getting to bypass veterinarians, judging by their submissions to the TGA, which had invited public comments while mulling its decision. One farmer, Rae Young, said he had been using Numnuts readily on his flock of 7,000 sheep and favored more direct access. "Having [provided] pain relief to over 20,000 lambs, we find the system of dispensing safe and easy to use," he said.

Dr. Jim Rothwell, a veterinarian who works for the Australian state of New South Wales in a senior biosecurity role, also supported the move. "I think making pain relief products more freely available and cheaper for sheep producers will improve animal welfare outcomes and improve the reputation of Australia's sheep meat and wool products," he said in his submission.

Country practitioners plead for recognition

Rural veterinarians contacted by the VIN News Service appeared to be of two minds. On one hand, they showed enthusiasm for Numnuts' ability to improve animal welfare. On the other, they were concerned about its distribution being taken out of their full control.

"We're experiencing quite a crisis when it comes to attracting and keeping vets in bush areas," said Dr. Jillian Kelly, a consultant to the livestock sector based in rural New South Wales. "Anything that diminishes the viability of those businesses is just another kick in the guts."

Both she and the AVA's Swaney maintain that prescribing painkillers can provide an important touchpoint between farmers and veterinarians, offering the opportunity for veterinarians to provide advice that could ultimately improve farm productivity.

"Your vet is still the best place to get information on which painkiller to choose, how to use them, what the pitfalls might be, tips and tricks for using them," Kelly said. "And then there's loads of other things that rural practitioners can offer, like disease management and nutritional advice. They can add dollars to your bottom line and they can significantly add to the health and productivity of your livestock."

Dr. Andrew Whale, a large animal practitioner based in the state of Victoria, acknowledges the TGA's point that Numnuts is designed to perform procedures done by farmers alone. "My argument back is that's clearly indicating that sheep producers in Australia don't have a relationship with a vet — and to me, that's a huge problem. Simply making it easier for people to not have a relationship with a vet is a really short-term fix for providing good animal welfare in Australia."

Whale suspects that lawmakers in Australia and around the world increasingly will start mandating that animals undergoing procedures such as castration receive pain relief. "The millions in profits generated from that could have gone straight into employing vets," he said. "Instead, they'll be redirected to rural merchandisers, which are not going to provide professional technical advice to sheep farmers. I just think it's a huge opportunity that's been missed by the industry."

In light of the TGA's decision, Whale said he and other veterinarians might start selling injectable lidocaine in bulk, potentially offering farmers a cost-competitive alternative to the Numnuts product. The applicator device is listed on the Numnuts website at A$396 (US$268) including sales tax. The NumOcaine refills it uses cost a little over A$43 (US$29) per 100 milliliter bottle, suitable for 65 procedures, according to a "recommended retail price" estimate on the website that assumes bulk buying.

As for elsewhere, it appears that Australia will be the only country in which Numnuts will be made available over-the-counter — at least in the near future. Senesino's Deans said the company doesn't need to request similar rule changes in New Zealand and the U.K., in part because they are smaller countries where farmers can more easily access veterinarians. Still, he said it wasn't immediately apparent to Senesino when it entered Australia in 2019 that it wanted to market over-the-counter there. "Until you're in there selling, it's really hard to assess what your next steps will be," he said.

Senesino, he added, has no current plans to launch Numnuts in North America, which he noted has a relatively small sheep population. Australia is the world's biggest wool producer and a heavy hitter in the export of sheep meat, including lamb.

Looking forward, all the veterinarians opposed to the TGA decision who spoke to VIN News said they'd accepted the change and were prepared to move on. At the same time, they stressed that farmers can still buy the drugs, and the Numnuts device, from veterinarians.

"I just really hope that producers keep coming to rural vets," Kelly said. "Rural clinics need that bread-and-butter work if we're going to be able to pull the calves at midnight and treat the snake-bitten dogs on Saturday — all those other things that rural veterinary services bring to the bush."

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