Pain mitigation for dehorning calves

Veterinarians can use a variety of methods to help clients reduce the stress and pain associated with dehorning, according to the American Association of Bovine Practitioners Animal Welfare Committee.

In a note to AABP members, the committee notes that research has shown dehorning, and even disbudding calves at an early age of less than four weeks causes pain and distress, regardless of the method. Research has also demonstrated that calves benefit from the mitigation of both the pain associated with the procedure itself and during the recovery and healing period.  The administration of local anesthesia such as lidocaine, in combination with non-steroidal anti-inflammatory drugs such as meloxicam, has been shown to provide effective pain mitigation during and after hot iron, cautery and amputation dehorning methods, according to research cited by the committee.  

AABP also notes that using a local anesthetic does not appear to address the immediate pain associated with the use of caustic paste, and in fact may make it worse. However, providing an anti-inflammatory drug such as meloxicam prior to the application of caustic paste can minimize post-procedural pain. When combined with a sedative (xylazine), research has shown that caustic paste results in less pain to calves than dehorning with a hot iron combined with a sedative and local block. Use of xylazine as a sedative also can help mitigate distress associated with the handling and restraint required for dehorning.

It is important to note that meloxicam is not labeled for use in cattle in the United States, but veterinarians can administer it under the Animal Medicinal Drug Use Clarification Act (AMDUCA).

In a recent letter from the FDA’s Center for Veterinary Medicine it was stated that extra-label use of drugs “is limited to treatment modalities when the health of an animal is threatened or suffering or death may result from failure to treat. We (the CVM) consider the use of analgesics and anesthetics for the purpose of alleviating pain…an acceptable justification for using approved drugs in an extralabel manner.” Based on the terminal plasma half-life reported in dairy calves of 40 hours, a conservative meat withdrawal interval of 21 days is recommended.

According to AABP, meloxicam is available through several commonly used distributors. Current prices for a 1,000-count bottle of 15mg tablets means you can medicate calves at 0.45 mg/lb (1mg/kg) for less than a dime per hundredweight.

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?

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?

This past week, the Wall Street Journal ran an article on the decline of tail docking in the dairy industry. It cited the recent resolution by the National Milk Producers Federation to alter its position and oppose routine tail docking except in cases of traumatic injury to the animal.

The NMPF now recommends the practice be phased out completely by 2022, giving producers time to implement on-farm management changes to address udder hygiene, parlor design, worker safety and other reasons commonly cited for tail docking. The American Veterinary Medical Association and American Association of Bovine Practitioners already oppose tail docking, and the practice has been banned in California; other states will surely follow.

Activists undoubtedly see the decline in tail docking as a victory. However, the NMPF resolution also represents a victory of sorts for the dairy industry by taking control of the issue, and shaping it to minimize its impact on producers. In a letter to NMPF members, President Jerry Kozak wrote, “Rather than give the animal rights community a tool with which to beat on dairy farmers, it’s more prudent to be proactive, and use our heads to handle this ourselves.”

What does this mean for dehorning? It means the industry may soon need to take control of this narrative – as the NMPF has done with the issue of tail docking – and shape it so it not only aligns with changing welfare standards, but allows producers time to adjust for minimum negative impact on their operations.

What do you think of the new NMPF resolution opposing tail docking?