Pain management in both companion and food animals has been a subject of growing interest over the past decade-plus. Now, it may be the next market access issue for the dairy industry, meaning food purveyors and consumers may soon demand its use.
Pamela Ruegg, DVM, MPVM, Professor in the Department of Dairy Science at the University of Wisconsin, Madison, told the audience at the 2017 American Dairy Science Association Annual Meeting that pain management for horn removal is one of a handful of key issues that will affect the U.S. dairy industry in the near term.
Several research studies have examined various pain-management techniques used in conjunction with cautery disbudding and surgical dehorning, but few have focused on pain management using caustic paste for disbudding, which typically happens in the first few weeks of life. A study conducted at the University of Guelph and published in the Journal of Dairy Science recently examined pain-abatement methods in conjunction with caustic paste for disbudding.
Charlotte Winder, DVM, DVSc, Postdoctoral Fellow in the Department of Population Medicine at the University of Guelph, led a team of researchers who evaluated pain management in conjunction with topical disbudding with caustic paste. Prior to the study, Winder conducted a survey and found that more than 60% of Ontario dairy producers have changed their disbudding practices over the past 10 years, primarily due to concerns about calf welfare.
In the new study, 72 group-housed, autofed, Holstein calves divided into 4 treatment groups:
- Placebo (non-caustic) paste and a saline cornual block;
- Caustic paste containing lidocaine and prilocaine for topical pain prevention, plus a saline cornual block;
- Commercial caustic paste accompanied by a cornual nerve block containing lidocaine;
- Commercial caustic paste with a saline cornual block.
All calves received a subcutaneous injection of 0.5 mg/kg of meloxicam at the time of the block. Incidence of pain was measured by evaluating validated pain behaviors (head shaking, head rubbing); pressure sensitivity of the horn-bud area; respiratory and heart rate; latency to approach human the evaluator; play behavior; feeding behavior; and standing and lying bouts.
Their study showed that caustic paste appears to cause pain for at least 180 minutes after application. Calves in group (3) that received a local anesthetic nerve block prior to paste application had less pain sensitivity than calves that received a caustic paste containing anesthetic or calves that received a saline cornual block prior to paste application. Pain did not appear to be significantly reduced by adding topical pain-management treatment to the caustic paste.
The researchers concluded by recommending that calves disbudded with caustic paste receive local anesthetic with a cornual nerve block as well as a systemic, nonsteroidal anti-inflammatory drug to mitigate acute pain.
You can read an abstract of the study here