Horn Talk Blog

According to a recent survey, about 18 percent of U.S. dairy producers use pain management for dehorning or disbudding. A slightly greater percentage of bovine veterinarians use pain relief for castration, which is typically performed at the same time as dehorning. One reason may have to do with the lack of approved pain medication.  Currently, no drugs are approved by the Food and Drug Administration Center for Veterinary Medicine (CVM) for managing pain in livestock. This leaves the veterinarian and producer liable for problems arising from extra-label use, including milk and meat withdrawal. Numerous compounds are approved for managing pain in companion animals like dogs and cats. Why not pigs, sheep and cattle?

CVM requires proof of both safety and effectiveness before labeling a drug to treat or prevent a specific condition in a specific species. Food animals like cattle tend to be quite stoic, or seemingly indifferent to pain; currently, no validated methods exist for evaluating pain responses in food animals. However, despite the lack of approved analgesics for livestock, evidence is mounting that large-animal veterinarians are taking pain management more seriously than ever.

The latest issue of Veterinary Clinics of North America: Food Animal Practice is the first issue devoted entirely to the subject of pain management, featuring 12 different articles on topics such as behavioral responses of cattle to pain, managing pain associated with castration, lameness or surgery, and injectable anesthesia in ruminants. In one article, “Bovine Dehorning: Assessing Pain and Providing Analgesic Management,” university researchers look at various methodologies for evaluating pain following dehorning, review published literature, and recommend a multimodal approach to analgesia using local anesthetic, nonsteroidal anti-inflammatory drugs (NSAIDs) and, when possible, a sedative-analgesic.

Earlier this year, the Veterinary Medical Association (AVMA) updated its Animal Welfare Policy on Dehorning and Castration to include the use of local anesthetics and NSAIDs to relieve both postoperative and preoperative pain for dehorning procedures other than disbudding. Within the past 18 months, the Dairy Calf and Heifer Association (DCHA) updated its welfare standards to specify disbudding as the “preferred” method for horn removal, recommending “cautery” at less than one month of age with local anesthesia, and approving local anesthesia and sedation for dehorning up to three months of age.

All these initiatives point to an increasing industry awareness of the importance of analgesia, and a growing willingness to use a variety of pain management strategies and compounds, federally approved or not. At the same time, CVM is encouraging researchers to provide validated methods for evaluating pain, and drug companies to develop innovative analgesics, all of which may soon lead to the development and approval of pain medications for livestock.

Fifty years ago, such an extensive examination of pain management in food animals would have been unthinkable. Consumers today are better educated than ever, and want assurances that their food is produced in a safe and humane matter. As the food animal system moves toward greater transparency, pain management will become increasingly important for producers, veterinarians, researchers, drug companies and regulatory agencies alike.

Back in 2008, a leading veterinary researcher and educator predicted that some type of analgesia could be mandated for castration and dehorning “within the next five to 10 years.” Will 2013 be the year that pain management will become a required management practice for producers? Will your operation be ready?

A wide range of behavioral and physiological responses occur in calves that are dehorned. A recent Texas Tech University study examined these responses in three-month-old Holstein calves undergoing dehorning or castration or both, and the effectiveness of pain relief in reducing these responses. The results provide a fuller picture of observable and biological responses to two very common management practices, with implications for both the beef and dairy industry.

We should note first of all that, at three months of age, the calves in this study were well beyond the point where more humane disbudding methods such as caustic paste could be performed. Horn buds attach to the skull by eight weeks, which is one reason why many industry organizations like the American Veterinary Medical Association (AVMA) recommend dehorning be performed “at the earliest age practicable.” The dairy calves in this study were dehorned mechanically using a Barnes or “Gouger” dehorner.

Second, pain relief was administered just prior to the procedure in the form of a local anesthetic and non-steroidal anti-inflammatory drug (NSAID). This is consistent with the AVMA’s updated welfare policy on dehorning, which recommends such pain relief methods for dehorning procedures other than early-age disbudding.

The study results show:

• Calves that were dehorned spent more time head shaking and ear flicking than control animals -- typical behaviors associated with dehorning pain.

• Dehorned animals showed a rise in concentrations of cortisol, a hormone released in response to stress, as well as other physiological responses to inflammation.

• Calves that were dehorned and not given pain relief spent less time eating than control calves, and lost roughly one percent of their body weight in the 24 hour time period following the procedure.

• In contract, calves that received pain relief in the form of an anesthetic and analgesic immediately prior to dehorning gained approximately 1.4 percent of their bodyweight in the 24 hours after the procedure – the same amount of weight gained by control calves over the same time period.

Although the differences in weight gain between the calf groups were not statistically significant, the findings suggest that the use of both local anesthesia and analgesia prior to dehorning can minimize “detrimental consequences” on calf performance and therefore economic losses. We took a look at some of the other economic benefits of pain relief for dehorning in a blog post last fall.

Such losses can be further minimized by disbudding at the youngest age possible, ideally at or within a few days of birth, preferably with a non-invasive method like caustic paste. Todd Duffield from the University of Guelph Ontario Veterinary College has noted that it is generally accepted that the younger the animal is the less painful the dehorning procedure is.

Early disbudding and pain relief aren’t topics typically raised in discussions over improving economics in the beef and dairy industry – but maybe it’s time they were.

Does early disbudding and pain relief make economic sense for your operation?

Every five years, the American Veterinary Medical Association (AVMA) reviews its animal welfare policies. The 80,000-member organization recently updated its Animal Welfare Policy on Castration and Dehorning with input from AVMA members and the American Association of Bovine Practitioners (AABP). On the subject of dehorning, the Animal Welfare Committee made two changes:

• The policy now contains a mention of the importance of genetics in selecting for the polled (hornless) trait.

• The policy now includes language recommending the use of local anesthetics and nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve postoperative pain as well as preoperative pain for dehorning procedures other than disbudding.

We applaud the AVMA for expanding its recommendation for pain relief during dehorning. We’re also pleased to see the organization drawing a sharper distinction between disbudding and “other dehorning procedures.” This is a tacit acknowledgement that disbudding is indeed less invasive and more painful than other methods of horn removal.

Other elements of the policy remain unchanged, including statements that:

• Dehorning is painful.

• Dehorning is important for human and animal safety (this is where the AVMA parts ways with most animal activists).

• Dehorning should be performed at the earliest age practicable.

• Research leading to new or improved pain relief methods is encouraged.

• Disbudding is still the preferred method for dehorning calves.

The AVMA is arguably the largest supporter of animal welfare in the United States, and its recommendations should be taken seriously by both livestock producers and animal activists alike. We hope the AVMA considers including a recommendation for caustic paste disbudding, the least invasive dehorning method, in its next round of welfare policy updates.

What do you think of the AMVA’s revised position on dehorning?