Introduction

Over recent decades, scientific research has demonstrated that animals experience physical and psychological pain.^{1,2,3,4,5,6,7,8},^a In the dairy and beef cattle industries, the recognition and treatment of pain in cattle is an important aspect of minimizing animal discomfort and optimizing animal health and well-being,⁹ thereby maximizing production and profit.^{10,11,12,13,14} Additionally, consumer awareness and scrutiny of painful routine management practices in cattle are growing.^15,16 Changes in physiology and behavior indicative of pain, such as immobility, abnormal posture,^17,18,19,20 and increases in heart rate^21,22 and blood cortisol concentration,^23,24 are commonly observed in cattle during and after routine procedures such as castration^3,17 and disbudding or dehorning^{18,19,21,22,23,24,25,26,27,28,29} and when affected by diseases such as lameness^2,30,31 and mastitis.^32,33 Furthermore, in cattle undergoing castration and disbudding or dehorning procedures, signs of pain can be alleviated and sometimes eliminated by administration of analgesics.^{17,23,26,28,34}

Pharmaceutical interventions to mitigate pain in cattle typically fall into 2 categories, local anesthetics and systemic analgesics. Administration of local anesthetics to block specific nerves and provide regional analgesia is commonly used to control acute incisional pain during dehorning,^20,26,27 castration,^35,36 and abdominal surgery. In animals, administration of a local anesthetic can reduce pain-specific behavior and biomarkers for several hours^20,37,^a; however, behavior and biomarker alterations indicative of pain return after the local anesthetic is cleared from the area.²⁴ Administration of a systemic analgesic (eg, NSAID) in combination with a local anesthetic can enhance or maximize the efficacy and duration of the analgesic protocol, particularly after painful procedures, in animals.^25,26,27,36

In the United States, flunixin meglumine is the only drug approved by the FDA for the control of pain in cattle, specifically pain associated with interdigital phlegmon (foot rot).³⁸ However, there are a number of NSAIDs approved for the treatment of pain in livestock species in the UK and Canada.^7,39,40 The lack of FDA-approved analgesics for cattle makes the implementation of pain mitigation protocols on cattle operations challenging from both financial and practical perspectives for US veterinarians and producers.^35,38 Nevertheless, the recognition of and ability and willingness to manage pain in livestock species have progressed greatly over the past 20 years, although pain mitigation often requires the use of drugs in an extralabel manner.^{35,38,39,40,41}

The veterinary literature contains little information about the use of pain mitigation strategies on US cattle operations. An understanding of current pain mitigation practices and the challenges associated with those practices is necessary to guide future research and education efforts and benchmark progress regarding management of pain in food animal species. The purpose of the study reported here was to survey cattle producers' and veterinarians' current opinions and use of local and systemic analgesics on US cattle operations.

Materials and Methods

Results

Summation of the member lists for the 6 target groups indicated that the potential maximum target population totaled 46,577 people, assuming that there was no overlap in the memberships of the target groups (ie, each invitee was a member of only one of the target groups). One thousand seven hundred ninety surveys were returned; therefore, the estimated response rate was 3.8% (1,790/45,577). Of the 1,790 returned surveys, 568 were excluded from further analysis because they were < 80% complete and 35 were excluded because investigators deemed that the respondent's role in the cattle industry was too far removed from treating and caring for cattle (ie, the respondent indicated that they were a nutritionist, seedstock or semen salesperson, artificial insemination technician, or geneticist). Thus, responses from 1,187 surveys in which at least 80% of the questions were answered by respondents who identified themselves as cattle producers, veterinarians, or both producers and veterinarians (producer-veterinarians) were included in the analysis. Because some questions were not answered by all respondents, the number of responses varied among questions.

The demographics of respondents were summarized (Table 1). Of the 1,187 respondents, 497 (41.9%), 569 (47.9%), and 121 (10.2%) self-identified as cattle producers, veterinarians, and producer-veterinarians, respectively. The majority of producer (399/497 [80.3%]), veterinarian (361/569 [63.4%]), and producer-veterinarian (74/121 [61.2%]) respondents identified as male. Of the producer respondents, approximately half were 51 to 70 years old (253/497 [50.9%]), whereas only 33 (6.6%) were between 21 and 30 years old, and 57 (11.5%) were > 70 years old. Conversely, among the veterinarian respondents, most (351/569 [61.7%]) were < 50 years old. The proportional age distribution of producer-veterinarian respondents was similar to that of veterinarian respondents.

Although all 5 US geographic regions were represented in the survey, most of the producer (209/497 [42.1%]), veterinarian (297/569 [52.2%]), and producer-veterinarian (62/121 [51.2%]) respondents had cattle operations or veterinary practices located in the Midwest region. The northeast region was represented the least among producer (45/497 [9.1%]) and producer-veterinarian (6/121 [5.0%]) respondents, whereas the southeast region was represented the least among veterinarian respondents (62/569 [10.9%]).

Of the 497 producer respondents, 173 (34.8%) indicated that they had completed a bachelor's degree and 167 (33.6%) indicated that they had received some postsecondary education (some college, trade school, or associate degree). Of the 121 producer-veterinarian respondents, 30 (24.8%) indicated that they had completed a PhD degree in addition to their professional (DVM, VMD, or equivalent) degree. The largest percentage of respondents in the veterinarian (300/569 [52.7%]) and producer-veterinarian (56/121 [46.3%]) categories indicated that they had graduated from veterinary school in 2001 or later.

Discussion

Current methods for providing analgesia to veterinary patients primarily involve the use of combinations of regional nerve blocks (local analgesia) and drugs with anti-inflammatory properties (systemic analgesia).^{6,17,18,19,20,23} However, in the United States, analgesia options for cattle are limited^17,35,38,43 owing to federal regulations regarding drug use in food-producing species, the lack of availability or cost of analgesics, and concerns about milk and meat withdrawal intervals.^35,38 Research that indicates producers and veterinarians are interested and willing to invest in effective analgesia options for cattle would likely encourage product development and availability. Previous surveys^{33,35,38,39,41,44,45} regarding the use of analgesia in cattle have been limited to veterinarians in various countries and did not include cattle producers, who are at the forefront of initiating pain mitigation protocols on their operations. The study reported here provided some insight into the current attitudes of US veterinarians and producers regarding the use of analgesia in cattle. This information can be used to facilitate further investigation into barriers to the adoption of best management practices for mitigating pain in cattle.

The estimated response rate for the present survey was 3.8% (1,790/45,577), which was lower than the response rates for similar surveys^33,35,38,39 that included only veterinarians but comparable to that of a survey⁴⁶ conducted by a lay publication that had a similarly sized target population (approx 40,000) as this survey. Given the method used to disseminate the present survey, it was impossible to accurately determine the number of people actually invited to participate. We believe that the true response rate for the present survey was somewhat higher than 3.8% because it was likely some invitees were members of more than 1 of the 6 target groups. The online nature of the present survey may have contributed to the low response rate and sampling bias because respondents had to have internet access and be willing and comfortable taking an internet-based survey. Additionally, the people who responded to the present survey may have had a particular interest in pain mitigation in cattle that prompted them to participate and might have been another source of sampling bias.

The majority (834/1,187 [70.3%]) of respondents to the present survey identified themselves as males, which was similar to the proportion of male respondents in similar surveys.^35,38,47,48 Results of the present survey indicated that men were less likely to administer local and systemic analgesia to cattle. That finding was consistent with results of other surveys,^{38,39,41,49,50,51} which suggest that men tend to be less empathetic than women about the presence and severity of pain in animals. Results of a 2013 survey⁵² of Finnish dairy producers indicate that women are more likely to administer analgesics to calves than are men. It is difficult to speculate on the psychological or sociological reasons for differences between men and women in regard to analgesia in cattle. Moreover, the effect of gender on the frequency of analgesia use in cattle identified in the present survey should be interpreted cautiously given the overrepresentation of men in the respondent population.

In the present survey, the proportion of respondents from the Midwest (568/1,187 [47.9%]) exceeded that of the other 5 geographic regions. The proportion of respondents from the Midwest region was likewise greatest for other similar surveys of US veterinarians^35,38 and cattle producers.⁴⁶

The numbers of veterinarians and producers who responded to the present survey were fairly balanced. In 2 surveys^47,48 of veterinarians and dairy producers regarding disbudding and dehorning practices in Ontario, Canada, producer respondents outnumbered veterinarian respondents by an approximate ratio of 3:1. Results of the present survey suggested that analgesia use increased with cattle age, which was similar to the findings of other studies regarding analgesia use in cattle by US^35,38 and Canadian³³ veterinarians. Results of a survey⁵³ of beef cow–calf producers in western Canada likewise suggested that analgesia use increased with cattle age. It is possible both veterinarians and cattle producers perceive that young animals are less capable of feeling or becoming distressed by pain than are older animals. That perception may stem, in part, from the long-held belief that human infants and young animals were incapable of remembering painful experiences owing to an immature nervous system.⁵⁴ However, research suggests that both human infants^54,55 and young laboratory animals⁵⁴ can feel acute pain intensely and remember painful experiences, as evidenced by altered responses to subsequent painful stimuli.

To our knowledge, the present survey was the first to compare the use of local and systemic analgesia for cattle undergoing various routine procedures or treatment for common diseases between US veterinarians and producers. In the present survey, the percentage of veterinarian respondents who used local analgesia most of the time or always for dehorning ranged from 64.7% (368/569) for calves < 2 months old to 77.3% (440/569) for cattle > 12 months, whereas the percentage of producer respondents who used local analgesia for the same purpose ranged from only 19.9% (99/497) for calves < 2 months old to 17.9% (89/497) for cattle > 12 months old. Results of Canadian^47,48 and Finnish⁵² surveys likewise indicate that veterinarians use local analgesia for disbudding or dehorning cattle more frequently than do dairy producers. Findings of a 2004 survey⁴⁸ conducted in Ontario, Canada, indicated that only 22% of dairy producers, compared with 92% of veterinarians, used local analgesia for dehorning cattle. Results of a similar survey⁴⁷ conducted 10 years later indicated that the percentage of dairy producers who used local analgesia for dehorning cattle had almost tripled to 62%, whereas the percentage of veterinarians increased only slightly to 97%. In the present survey, responses were not analyzed on the basis of cattle type (beef or dairy). Use of polled genetics is popular in the beef industry, which may decrease the frequency with which beef producers and veterinarians are required to disbud or dehorn cattle.

In a survey³⁸ of 666 US cattle veterinarians published in 2011, 68.1% and 69.5% of respondents reported that they provided analgesia more than half the time for dehorning beef calves < 6 and > 6 months old, respectively, and 62.5% and 74.0% of respondents reported that they provided analgesia more than half the time for dehorning dairy calves < 6 and > 6 months old, respectively. Unfortunately, results of the present study indicated that routine use (ie, most of the time or always) of analgesia for dehorning cattle had not substantially changed over the past decade. In response to consumer demands during recent years, many large dairy product processing companies have established animal welfare policies and mandated that dairy farms from which they purchase milk undergo routine animal welfare audits, which require that local analgesia be administered prior to disbudding or dehorning of dairy cattle, with the recommendation that all calves be disbudded before 8 weeks of age whenever possible.^56,57 Thus, it is anticipated that producer and veterinarian use of analgesia for disbudding and dehorning of dairy cattle will increase in the near future.

Results of surveys^39,41 of UK veterinarians indicated that a large proportion (95% to 98.7%) use local analgesia for disbudding and dehorning cattle. However, it would be inappropriate to compare those results with those of the present study owing to the fact that the UK has stricter regulations than the United States regarding the use of analgesia during painful procedures in veterinary patients.⁵⁸ In the UK, dehorning of cattle, regardless of age, must be performed with analgesia except when chemical paste is used for the procedure. Also, in the UK, castration of calves > 8 weeks old must be performed with analgesia, and band castration is permitted only in calves < 1 week old.

Historically, in cattle, the use of local anesthesia or analgesia for castration was less common than for dehorning.^30,38,39,41 Administration of a local anesthetic block for castration of calves, particularly on beef operations where animals are less intensively handled than on dairy operations, is challenging, and the time required to effectively block the testicular region may be daunting to some producers, especially when a large group of calves need to be castrated. However, producers and veterinarians should consider the benefits of analgesia to calf welfare^17,29,36 as well as public perception of castration when deciding whether the time and effort required to administer a local anesthetic for the procedure are worthwhile. In a survey³³ of Canadian veterinarians conducted in 2004–2005, > 80% and > 60% of respondents indicated that they did not use analgesia to castrate calves < 6 and > 6 months, respectively. In a 2010 survey,³⁵ 42 of 189 (22%) US veterinarians indicated that they routinely used local analgesia when castrating calves. Among the 569 respondents of the present study, 184 (32.3%) and 221 (38.8%) veterinarian respondents indicated that they used local analgesia most of the time or always for surgical castration of calves < 2 and 2 to 12 months old, respectively. Collectively, those results suggested that veterinarian use of local analgesia for castration of cattle in North America has increased over the last 15 years. Potential reasons for that increase include more emphasis on the importance of analgesia in cattle in veterinary curricula and continuing education programs and increased pressure on the cattle industry by consumers demanding improvements in animal welfare.

In the present survey, the proportions of producer respondents who indicated that they used local analgesia most of the time or always for surgical castration of calves < 2 (56/497 [11.3%]) and 2 to 12 (65/493 [13.1%]) months old were approximately a third that of the corresponding proportions for veterinarian respondents. Results of a survey⁴⁸ of dairy producers and veterinarians in Ontario, Canada, indicate that there is a positive correlation between producer use of local analgesia for painful procedures, such as castration and dehorning, and the collaborative relationship with a veterinarian. Most drugs used for local analgesia are available only by prescription; thus, producers must have a valid veterinarian-client-patient relationship to acquire those drugs.⁵⁹ It is also possible that dairy producers who are willing to provide analgesia for painful procedures have seen the benefit of investing in a collaborative relationship with their veterinarian to improve overall animal welfare.

Options for systemic analgesia in cattle in the United States are limited relative to those available in Canada and the UK.^38,43 In the United States, the NSAID flunixin meglumine is the only drug approved by the FDA for treatment of pain in cattle, specifically pain associated with foot rot in beef cattle and dairy heifers < 20 months old. The use of flunixin meglumine for the treatment of pain not originating from foot rot or any other NSAID or local anesthetic (eg, lidocaine) to treat any type of pain in cattle is allowable under AMDUCA only within the confines of a valid veterinarian-client-patient relationship.^59,60 In Canada and the UK, meloxicam, an NSAID with a longer half-life than flunixin meglumine in cattle, is approved for the treatment of pain in cattle.^{18,43,61,62,63} Administration of meloxicam to cattle prior to painful procedures appears to alleviate behavioral and physiologic indices of pain⁶⁴ and is allowable under AMDUCA in the United States.⁵⁹

The proportion of veterinarian respondents who reported always using systemic analgesia for surgical castration of calves 2 to 12 months old (116/569 [20.4%]) was similar to that reported by respondents of a 2010 survey³⁵ (40/189 [21.2%]) of US veterinarians. However, in the present survey, 80 of 569 (14.1%) veterinarian respondents indicated that they used systemic analgesia for castration of calves 2 to 12 months old most of the time, which suggested that systemic analgesia for castration of cattle in the United States may be more common than it was 10 years ago.

Results of the present survey indicated that veterinarians administered systemic analgesia for dehorning more frequently than for castration. However, the proportion of veterinarian respondents who always administered systemic analgesia for dehorning was < 50% across all 3 age groups. The dehorning guidelines issued by the American Association of Bovine Practitioners in 2019 states that concurrent administration of analgesia should be the standard of care for all dehorning and disbudding procedures.⁶⁵ Given research that indicates calves experience pain during disbudding and dehorning procedures^66,67 and the commitment of the veterinary profession to alleviate both acute and chronic pain in animals,⁶⁸ the proportions of respondents who reported using local or systemic analgesia in the present survey were low and improvements are necessary.

In the present survey, the odds of local and systemic analgesia use by veterinarian respondents were significantly greater than those for producer respondents for almost all procedures and diseases assessed. Similarly, in a survey⁴⁷ conducted in Ontario, Canada, a greater proportion of veterinarians reportedly used local and systemic analgesia for dehorning cattle than did dairy producers. Regardless, in the present survey, the proportions of producers who reported administering local, and particularly systemic, analgesia most of the time or always for common procedures, such as surgical castration and dehorning, were fairly low. The lack of products approved by the FDA for the treatment of pain in cattle might have contributed to the low producer use of analgesics in cattle owing to restrictions regarding extralabel drug use in food-producing species and concerns about avoiding violative drug residues in milk and meat when drugs are administered in an extralabel manner. The availability of FDA-approved analgesics for use in cattle would likely improve the adoption of pain mitigation protocols by producers.

Respondents of the present survey had the option of indicating that they would not perform each procedure or treatment assessed. However, given the way the questions were asked, we could not determine whether respondents chose that response because they had no need or desire to perform a procedure (eg, raised naturally polled cattle and therefore dehorning animals was not required), were unable to perform a procedure (eg, many producers leave abdominal surgeries to veterinarians), or did not perform the procedure for some other reason. Future surveys should ask respondents to explain why they would not perform specific procedures.

To our knowledge, the present study was the first to assess the extent of agreement with specific statements regarding pain and the use of analgesia in cattle by producers. Results indicated that many veterinarians and producers appreciated the benefits of analgesia and had or were interested in implementing pain mitigation protocols on their operations. The frequency distributions for veterinarians' responses to the statements of the present survey were similar to those for similar statements in surveys of veterinarians in the United States³⁸ and the UK.³⁹ Overall, it appeared that most veterinarians are cognizant of the benefits of analgesia and reject the suggestions that pain might be advantageous and analgesia may be more harmful than beneficial to some animals. Results of the present survey and the aforementioned surveys^38,39 also suggested that veterinarians occasionally encounter resistance to analgesic use by producers because of the drug costs.

As previously mentioned, the UK has stricter regulations than the United States regarding the use of analgesia during painful procedures in veterinary patients,⁵⁸ and comparisons between survey results of US and UK veterinarians should be made cautiously. For example, in a 2017 survey,³⁹ 29% of UK veterinarians agreed with the statement that European Union legislation limited their ability to use analgesics in cattle, whereas 509 of 569 (89.5%) veterinarian respondents of the present survey agreed with the statement that US-USDA-FDA regulations limited their ability to use analgesics in cattle. Additionally, the proportion of respondents who agreed with the statement that cost was a major factor in their ability to use analgesics in cattle was greater for US veterinarians (355/569 [62.4%]) than for UK veterinarians³⁹ (54/242 [22.3%]). This suggested that, in the United States, many veterinarians perceived federal regulations and the cost of analgesic drugs as impediments to the implementation of pain mitigation protocols on cattle operations.

Results of the present survey provided insight into current perceptions of US producers and veterinarians regarding the use of and impediments to pain mitigation protocols on cattle operations. The findings of this survey can be used to inform the beef and dairy industries regarding the creation and implementation of new drugs, policies, and stakeholder education for pain mitigation in cattle.