Pain relief for better animal health

Ethics focus: Dr Alison Holdhus Small, a principal research scientist for CSIRO Agriculture and Food, at Chiswick, Uralla with some lambs and the new Numnuts applicator. Photo: Stephanie van Eyk
Ethics focus: Dr Alison Holdhus Small, a principal research scientist for CSIRO Agriculture and Food, at Chiswick, Uralla with some lambs and the new Numnuts applicator. Photo: Stephanie van Eyk

The use of analgesia and pain relief for all livestock health procedures will be the way of the future as animal ethics become an important marketing consideration.

Dr Alison Holdhus Small, a principal research scientist for CSIRO Agriculture and Food, based at Chiswick, Uralla, said she expects more widespread use of pain relief and better animal welfare outcomes would be driven by market demand.

"One because it's the right thing to do and two because it's what markets in Europe and to a lesser extent the US and China are demanding to meet animal welfare standards," Dr Small said.

She said already some premiums were available for the use of pain relief, particularly when used in fine wool production.

"It could become hard to sell products that aren't branded as animal-friendly," Dr Small said.

Like people, animals suffer from two types of pain – a fast pain or initial pain then a slow building pain that increases over time. And the treatments are also similar, a local anaesthetic for the fast pain and non-steroidal anti-inflammatory drugs for the slow pain.

"These act on the damaged tissue and dial down the throbbing pain," she said.

Using both forms of pain relief gives the best results – for people and animals.

Much of her team's work has focussed on assessing the efficacy of pain relief available and looking at the best ways to administer the drugs. 

And, there are already a number of good products in use.

Market driver: Animal ethics is one area of research for the team at the CSIRO's FD McMaster Laboratory, Chiswick, Uralla.

Market driver: Animal ethics is one area of research for the team at the CSIRO's FD McMaster Laboratory, Chiswick, Uralla.

"When mulesing sheep, Tri-Solfen (Bayer) has a combination of local anaesthetics that block out the fast pain, but it's also got adrenalin which slows the bleeding and antiseptics to prevent infection," Dr Small said.

She believes about 75 percent of Merino sheep are given Tri-Solfen during mulesing procedures.

"It's a good product but the challenge is that it wears off. Adding an injection of an anti-inflammatory drug would give longer relief.

"Metacam20 (Boehringer Ingelheim) is an anti-inflammatory drug that is given by subcutaneous injection (under the skin), which will give at least another 48 hours of pain relief.

"It's only been registered for sheep since July last year and it's available through your local vet. Its with-holding period is only 11 days in sheep."

Another anti-inflammatory product that has recently been launched is Buccalgesic OTM (Troy Laboratories) which is absorbed through the mouth.

"It's given into the mouth, just like some medications for epileptic children that are placed under the tongue.

"Buccalgesic is delivered using a modified dosing gun with a special nozzle. It's approved for use in sheep and has been on the market for sheep since August last year – and a little longer for cattle. Again it will give another 48 hours of relief, is available from your local vet and its with-holding period is only 10 days in sheep.

"Its uptake for use in cattle for pain relief during marking is quite good."

The hard part of the equation is to quantify how the benefit to the animals from less pain, stress and a faster recovery translates into better results for producers. 

“There are so many other factors affecting survival and growth that it is really hard to tease out the contribution of the pain relief to improvements in production,” Dr Small said.

“However, we do know from human medicine that effective pain relief at surgery leads to faster recovery and longer term health benefits.”

Researchers use animal behaviour plus blood markers like cortisol and blood cell counts to determine pain and stress levels, and compare them with a control group.

To ensure handling stress is minimised so it doesn't interfere with the experiments, the lambs used in the trials at Chiswick are desensitised by having a regular cuddle.

"The sheep are handled to acclimate the sheep for about two weeks prior to the day of the procedure when they are in the animal house where we do the study," she said.

"They are caught and held at least twice a day. When we have students on placement, we have no shortage of volunteers for that task!”

No pain: Dr Alison Small and her team have developed a new ring applicator for lamb tails and testicles that can give a shot of local anaesthetic called Numnuts.

No pain: Dr Alison Small and her team have developed a new ring applicator for lamb tails and testicles that can give a shot of local anaesthetic called Numnuts.

In conjunction with 4cDesign in Scotland, Dr Small and her team have developed a new ring applicator for lamb tails and testicles that can give a shot of local anaesthetic.

Numnuts is an easy tool to use and was more ergonomic than many applicators on the market, however, it's not commercially available yet she said.

"We are trying to get a better local anaesthetic approved for use in lambs," Dr Small said.

"Those currently approved for use in sheep are too short acting – they do work, but the sheep clear the drug out of their system very quickly."

Dr Small said an excellent protocol for producers in the future would be using the Numnuts device with local anaesthetic, giving an anti-inflammatory, then feeding a ration that contains an anti-inflammatory drug for a few days after the procedure.

Award winners: Dr Alison Small and her team recently won an ethics award for their pilot program addressing better slaughter practices for buffalo in northern Australia.

Award winners: Dr Alison Small and her team recently won an ethics award for their pilot program addressing better slaughter practices for buffalo in northern Australia.

Dr Small's passion for best practice isn't just focused on the sheep industry.

She and her team recently won an ethics award for their pilot program addressing better slaughter practices for buffalo in northern Australia.

The top end has significant numbers of farmed and wild buffalo and there are frequent requests for export of buffalo to Indonesia and Malaysia.

But, buffalo – unlike cattle – have a thick bony plate where a traditional stunner would be used. So effective stunning, which is an important consideration for export, isn’t always possible using the traditional method for cattle. The trial, conducted at Darwin, involved looking at a variety of buffalo heads and working out where the "sweet spot" was located.

The pilot study went before an ethics committee based in Canberra that included a scientist, a vet, an animal welfare representative and a member of the public.

"They assess all the applications and decide whether or not the research is justified and ethical," Dr Small said. "Animal slaughter is such a difficult subject anyway."

Moving forward, the project will need to be run on a larger scale to validate the results which may mean the research is continued in Indonesia.

“At CSIRO, we carry out a wide range of research.  We’re very fortunate that the research is strongly supported by industry, through Meat & Livestock Australia, Australian Wool Innovation and Agrifutures, as well as the privet companies with which we work,” Dr Small said.