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Equine Behavior Problems—Around Farriery: Foot Pain in 11 Horses
Journal of Equine Veterinary Science 31 (2011) 44-48
Journal of Equine Veterinary Science journal homepage: www.j-evs.com
Clinical Techniques
Equine Behavior ProblemsdAround Farriery: Foot Pain in 11 Horses Richard A. Mansmann VMD, PhD, Hon DACVIM-LA a , M. Claire Currie DVM a, b, Maria T. Correa PhD c, Barbara Sherman DVM, PhD, DACVB a, Kurt vom Orde d a
Department of Clinical Sciences, North Carolina State University, Raleigh, NC Centre Equine Practice, Centre Hall, PA c Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC d Chapel Hill, NC b
a b s t r a c t Keywords: Horse Farrier Foot Hoof Pain Behavior
Although foot pain may clearly be the cause when a horse with foot pathology does not tolerate farriery, it may be overlooked or underappreciated as the cause of this behavioral problem when the pathology is mild and/or chronic. In this study, the records of 11 adult horses whose behavior for farriery initially warranted sedation for trimming and shoeing were reviewed. All 11 horses had a history of chronic lameness that was mild to moderate, but foot pain was the presenting complaint in only seven horses - all with chronic laminitis. The other four horses had abnormal foot conformation (long-toe, lowheel, or “club foot), but the lameness had not been attributed to the foot. All 11 horses showed improvement in gait with corrective trimming and shoeing. In each case, sedation for farriery could be discontinued after one to six visits, concurrent with the improvements in gait and foot pathology. On the basis of the survey results from 17 professional farriers, an ethogram of farriery-related undesirable horse behavior was developed. Ó 2011 Elsevier Inc. All rights reserved.
1. Introduction It should be self-evident that a horse with foot pain might be uncooperative for farriery work. Farriery requires the horse to stand on three feet while the fourth foot is lifted for hoof care. Thus, the load on the other three limbs, particularly the contralateral and diagonal limbs, is increased for the duration the fourth foot is raised. If one or more of those limbs is painful, this extra load can become intolerable. Farriery also involves variable amounts of compression, tension, twisting, and concussion on the hoof when the shoe and nails are removed, the hoof is trimmed, and the shoe is replaced. Routine farriery directly involves only the keratinized (i.e., insensitive) structures of the hoof, Current address: Richard A. Mansmann, VMD, PhD, Equine Podiatry and Rehabilitation Mobile Practice, Chapel Hill, NC. Corresponding author at: Richard A. Mansmann, VMD, PhD, Hon DACVIM-LA, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606. E-mail address: [email protected] (R.A. Mansmann). 0737-0806/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.jevs.2010.11.018
so it is not inherently an uncomfortable procedure. Even so, when digital pathology is present, routine farriery and all it entails can cause the horse to be uncomfortable and uncooperative. With obvious painful foot problems such as acute laminitis or a subsolar/submural abscess, the degree of lameness shown by the horse can be seen as a fairly reliable indicator of the degree of care needed when trimming and shoeing. It is entirely understandable that a horse with severe foot pain might be defensive and uncooperative toward the farrier, and perhaps even unpleasant with sufficient irritation. In such cases, the use of sedation or regional anesthesia (e.g., low palmar nerve block) may be the most practical and humane approach to addressing the horse’s farriery needs. The problem arises when the existence and amount of pain is not obvious, such as when a lameness is mild, chronic, inconsistent, or has not been localized to the foot or even to a single limb. In such instances, it can be difficult to determine whether the uncooperative behavior of the horse around the farrier is the result of foot pain or whether
R.A. Mansmann et al. / Journal of Equine Veterinary Science 31 (2011) 44-48
there is a possibility of another explanation. Other causes proposed include inadequate training, lack of discipline or improper restraint by the owner/handler, and a bad attitude toward people in general and farriers in particular as a result of a previous painful experience or reprimand. Most horses tolerate farriery after initial training when young by allowing the feet to be lifted and handled in a typical manner. With training, even horses with a mild to moderate lameness generally endure farriery if it is done with care; however, some may not be able to tolerate the pain, the reason for which may not be clear. It is our belief that some of these horses that are uncooperative have foot pain which has not been recognized or not been adequately addressed. This conclusion was drawn while observing the following: (1) many of these horses have hoof conformational abnormalities and a history of lameness; and (2) initial sedation for the purpose of farriery is no longer needed as the hoof problem improves in response to corrective trimming and shoeing. The purpose of the present study was to document these observations by collecting the clinical findings and outcomes for horses that were initially uncooperative for farriery necessitating sedation at least once, but then no longer required sedation as the feet responded to corrective trimming and shoeing. Additionally, we wanted to examine the number of times sedation was required by the horses for farriery so as to determine whether there was any association with the type of digital pathology present and the severity and duration of the lameness. We also wanted to document the types of behaviors shown by these horses toward the farrier that were considered uncooperative or unsafe for the farrier to work on the feet. An ethogram, which is a catalog of discrete behaviors typically used by a species, was developed as part of this study [1]. Ethograms have been developed for other aspects of equine behavior, such as the natural behavior of horses [2,3], stress-related behaviors in therapeutic riding horses [4], and the assessment of pain after major surgery [5]. Therefore, we produced one ethogram for uncooperative behaviors relating to farriery work. It is our goal that in publishing this observational study and ethogram, the interpretation of uncooperative behaviors can be expanded to specifically include the possibility of foot pain or other source of discomfort, and not be simply labeled as “bad behavior.” 2. Materials and Methods 2.1. Sedation for Farriery This retrospective study referenced the medical records for horses presented to the Equine Podiatry and Rehabilitation Service of North Carolina State University College of Veterinary Medicine over a 2-year period (2006-2008). Initially all the horses that required sedation for the farriery owing to their uncooperative or unsafe behavior around the farrier were included in the study. Horses aged <2 years were excluded from the study to avoid temporary or otherwise confounding behaviors that might primarily be explained by immaturity or early training; mature horses with incomplete records were also excluded. The compiled information included signalment, presenting complaint,
45
duration of complaint, the number of farriery visits conducted at the Equine Podiatry and Rehabilitation Service, the number of times sedation was required for farriery, and the outcome in terms of soundness. Because of the small number of horses that met the study criteria, no statistical analysis was performed. 2.2. Ethogram A one-page survey was sent to professional farriers in North Carolina regarding the types of poor behavior that might be shown by a horse during routine farriery work requiring the farrier to have the horse sedated, or refuse to work on the horse. On the basis of the responses, an ethogram was developed for farriery-related difficult behaviors in horses. 3. Results 3.1. Sedation for Farriery A total of 11 horses met the study criteria. Details are summarized in Table 1. Sedation in all cases included intravenous injection of detomidine hydrochloride (Dormosedan, Pfizer Animal Health, Exton, PA, USA) at the recommended dosage of 20 to 40 mg/kg bodyweight, to effect. The feet of all horses were trimmed and shod by the same experienced farrier (KVO). The study group included adult amateur performance horses, retired riding horses, and rescued horses. The various breeds represented in the study were consistent with the general clinic population. The age of these horses ranged from 6 to 21 years; the average age was 12 years. All 11 horses were presented because of lameness; foot pain was the presenting complaint or recognized by the owner in only seven horses, all of which had a history of laminitis. The remaining four horses each had an abnormal foot conformation (long-toe, low-heel [three horses]; or “club foot” [one horse]), but the lameness had not been localized to the foot. The degree of lameness at initial presentation varied among the study group; one consistent feature was that the lameness was chronic, ranging from months to years in duration. In all 11 horses, sedation for farriery was discontinued after one to more than three times; in seven horses, sedation was required for farriery only once or twice and in four on three or more occasions. There did not appear to be any clear association between duration of lameness and the number of times sedation was needed for farriery. Four of the seven horses requiring sedation only once or twice had been lame for a few months, but another two of these seven horses had been lame for several years. There also did not appear to be any clear association with age, breed, gender, presenting complaint, or lameness grade and the need for sedation. All 11 horses showed improvement in their lameness with corrective trimming and shoeing. Eight horses were able to resume some riding activities and two of the remaining three horses were normal enough to begin ground work. The remaining one horse in the study was pasture sound.
3.2. Ethogram Survey responses were obtained from 17 farriers. The ethogram of farriery-related poor behavior in horses is summarized in Table 2. The specific behaviors were generally categorized as either defensive/evasive or offensive/aggressive. 4. Discussion
WB, Warmblood; TB, Thoroughbred; QH, Quarter Horse; TWH, Tennessee Walking Horse; LTLH, long-toe, low-heel foot shape; WLD, white line disease; RF, right forelimb. Lameness grade: degree of lameness, scored on a scale from 1 (mild) to 5 (severe). Lameness duration: length of time lameness present before presentation. Sedation required: number of farriery visits when sedation was required for farriery.
3 2 1 1 3 2 2 6 1 1 4 5 4 11 6 6 >6 8 5 >4 LTLH, thrush, navicular disease, negative palmar angle; grade 2/5 at trot LTLH, thin soles, WLD; not graded Laminitis, WLD, foot abscesses; not graded LTLH, thin soles, hoof cracks, navicular disease; grade 2/5 occasionally Laminitis in all 4 feet; grade 3/5 at walk Laminitis, thin soles, seromas at toes; not graded Club foot, abscesses; grade 2/5 at trot Laminitis, WLD; grade 4/5 at walk Laminitis, club foot in RF; grade 2/5 at trot Laminitis; grade 3/5 at walk 6-year-old WB gelding 12-year-old WB gelding 14-year-old TB mare 11-year-old TB gelding 17-year-old Paso Fino gelding 21-year-old QH gelding 6-year-old TB mare 12-year-old QH mare 10-year-old TWH mare 7-year-old Paso Fino mare
7 months At least 3 months 3 months 4.5 years 11 months 8 months Lifetime 1.5 years 3 months 4 months
4 6 Chronic laminitis; grade 3/5 at walk 12-year-old Welsh gelding
6 months
Sedation Required Farriery Visits Lameness Duration Presenting Complaint and Lameness Grade Signalment
Table 1 Clinical findings and outcomes for 11 horses requiring sedation for farriery
Resumed use as school horse, giving 5 lessons/week Sound for light riding Improved In regular work Showing and jumping until died of colic Sound for light riding Used for light riding, still mildly lame on RF Pasture sound Comfortable for ground work Sound for light riding Sound for light riding
R.A. Mansmann et al. / Journal of Equine Veterinary Science 31 (2011) 44-48
Outcome
46
All of the horses in this study presented with a history of chronic lameness, and all had well-recognized foot pathology of one type or another. What makes this group of horses interesting is that the presenting complaint and the degree of lameness shown by most horses were not considered sufficiently painful or severe enough to require sedation for the purpose of farriery. Acute laminitis can be very painful and may necessitate sedation or regional anesthesia for initial farriery care, and often by the time laminitis is in the chronic phase, the lameness may be only mild to moderate. The long-toe, low-heel foot conformation, club foot, and white line disease are chronic conditions that typically cause only mild to moderate gait abnormalities. All of the foot problems, described in the horses in this study, are commonly encountered but seldom do horses with these clinical problems require sedation for farriery. It has been stated correctly that pain is an experience, not a physiological event that can be quantitated [6]. It is also well accepted that the experience of pain is highly variable among and between individuals, even with identical stimuli and environments [6]. This was our impression with the horses in this study group. There was neither clear association with age, breed, gender, presenting complaint, nor severity or duration of lameness for either the need for sedation or the number of times sedation was required for farriery. Conditions not expected to be painful appeared to be, based on the behavior of the horses toward the farrier and the clinical response to corrective trimming and shoeing. Although we do not know for sure what an animal is feeling, it has been proposed that pain affects behavior in recognizable ways; the degree of behavioral change correlates with the severity of the pain [6]. Thus, it also seems reasonable to conclude that specific behaviors demonstrated by horses in response to obvious painful stimuli may be indicative of pain in similar circumstances that are less clearly painful. As an example, the response to hoof testers or the farrier’s hammer shown by a horse with acute laminitis can reasonably be interpreted as a sign of pain when demonstrated in a horse with thin soles, crushed heels, lamellar detachment, or some other structural failure of the hoof, although there is less marked response. Horses with joint pain more proximally in the limb, for example in the carpus or tarsus, have also been known to be difficult with the farrier. Typically, these horses are more cooperative when the joint pain has been recognized and addressed by adjusting the position of the limb. Therefore, pain anywhere in the limb and in the axial skeleton can give an individual horse sufficient cause to be uncooperative around a farrier.
R.A. Mansmann et al. / Journal of Equine Veterinary Science 31 (2011) 44-48
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Table 2 Ethogram of farriery-related poor behavior in horses Behavior Defensive/evasive actions Snatching foot away Rearing or backing Fearful Unstill Moving away Offensive/aggressive actions Coming at the farrier Biting Striking or kicking Rude, bad manners Tail lashing
It is unlikely that the need for sedation ended because of improved training or maturity; the clinical history did not indicate past problems with routine foot care in the past since all horses were already trained to accept farriery. Each horse underwent observation at the clinic for only one or two hours, every 4 to 6 weeks, and during these visits no attempt was made by the veterinarian, handler, or farrier to train the horse to stand for the farrier. And although the farrier was patient, with all the horses, it is unlikely that these positive interactions would be enough to change a fixed behavior that was serious enough to require sedation. It is also unlikely that sedation directly contributed to a training effect, because positive behavioral results are not necessarily a result of using tranquilization or sedation [7], especially with the range in number of sedations used (in one to six visits) in the study group. We believe the need for sedation stopped because the therapeutic shoeing resolved the painful feet. Pain is a powerful stimulus and an easily learned response. If the uncooperative behavior of the horse was prompted by the recall of past pain during farriery, then one or two visits using a sedative-analgesic agent, detomidine, may have been sufficient to decrease the anxiety and pain associated with farriery resulting in cooperation on all the subsequent visits. However, in this study, pain in each horse appeared to be the stimulus for the poor behavior, and pain relief appeared to resolve the behavioral problem. In our review of the literature, we could neither find any studies which defined the types of undesirable equine behaviors relating to farriery, nor those that address the possible role of foot pain and the behaviors. The purpose of putting together an ethogram of farriery-related poor equine behaviors was to list the specific behaviors with the goal of an initial investigation and a basis for additional research studies. Clearly, pain is only one possible explanation for these poor behaviors. As mentioned, bad training or handling and the recollection of past pain/punishment in relationship to farriery need to be considered. Even so, pain is an important explanation of why a mature horse might behave poorly around a farrier, and it should be considered first. When it comes to pain, an animal should not have to tolerate it when there are safe and effective sedative and analgesic options. Furthermore, the farrier’s job can be challenging enough without having to deal with an uncooperative and potentially dangerous horse. When managing an abnormal foot, it is even more important that
Description Abruptly removing the foot and leg from the farrier’s placement Escape attempt, suddenly erupting violently Scared and unpredictable, trembling, shaking Refusal to stand still; includes leaning, pulling, other bad manners Escape attempt by moving away from the farrier Aggressively moving into the farrier Biting the farrier’s back when working Deliberate attempt to make contact with the farrier Nipping at the lead shank, stomping, bumping the handler Actively swishing the tail side to side
the farriers should be able to take their time and treat the foot properly. There is little reason to withhold sedation or regional anesthesia when a horse is behaving poorly and possibly unsafely for a necessary clinical procedure. With the availability of detomidine as an oral gel, the veterinarian may choose to dispense a dose of detomidine for farriery when pain and its associated cause have been identified as the reason for the poor behavior of the horse [8]. In our experience and based on our reported finding in this study, sedation can be expected to end the root cause of the pain if satisfactorily addressed. In conclusion, it is hoped that this study can be added to the new emphasis on better understanding of equine pain, its expressions, and causes [9]. It is also hoped that the study findings and ethogram help veterinarians and farriers to better interpret and understand the poor behaviors shown by horses around farriers. These behaviors may simply be the result of bad training, improper handling, or the recall of past pain/punishment. However, our findings propose that foot pain or other musculoskeletal pain should be considered an important rule out by a comprehensive physical examination before assigning the horse to the position of “bad” or “spoiled” when pain management is the better approach. Equine behavior that is unsafe around people and other horses cannot be tolerated, and a behavior that makes the farrier’s job more difficult is also unacceptable. We must take care not to forget the possible role of pain, either past or present, in rousing the horse’s behavior. To paraphrase the ethical maxim taught to all medical students: first, consider pain. Acknowledgments The authors thank Drs. Margaret Gruen, Peter Cowen, and Ms. Patricia A. Mansmann for their assistance and Julie Davis with technical help with this study, as well as all the farriers who participated. The authors also acknowledge the editorial input of Christine King, BVSc, MACVSc, MVetClinStud, and are grateful for partial funding from the NCVMF Gallop of Honor Podiatry Fund. References [1] Ethogram. Wikipedia, 2010. Available at: http://en.wikipedia.org/ wiki/Ethogram. [2] McDonnell S. A practical field guide to horse behavior: the equid ethogram. Lexington, KY: The Blood Horse Inc.; 2003.
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[3] McGreevy PD, Oddie C, Burton FL, McLean AN. The horse-human dyad: can we align horse training and handling activities with the equid social ethogram? Vet J 2009;181:12-8. [4] Kaiser L, Heleski CR, Siegford J, Smith KA. Stress related behaviors among horses used in a therapeutic riding program. J Am Vet Med Assoc 2006;228:39-45. [5] Sellon DC, Roberts MC, Blikslager AT, Ulibarri C, Papich MG. Effects of continuous rate intravenous infusion of butorphanol on physiologic and outcome variables in horses after celiotomy. J Vet Intern Med 2004;18:555-63.
[6] Hansen BD. Assessment of pain in dogs: veterinary clinical studies. Inst Lab Anim Res J 2003;44:197-205. [7] Wood T, Weckman T, Woods WE, Tobin T, Dougherty J. Detomidine: a preliminary analysis of its duration of action in the horse by variable interval responding. Equine Vet J 1988;20:320-2. [8] Gardner RB, White GW, Ramsey DS, Boucher JF, Kilgore WR, Huhtinen MK. Efficacy of sublingual administration of detomidine gel for sedation of horses undergoing veterinary and husbandry procedures under field conditions. JAVMA 2010;237:1459-64. [9] Sellon DC. Pain: the fourth vital sign? Comp: Equine Ed 2006:205-9.
Journal of Equine Veterinary Science journal homepage: www.j-evs.com
Clinical Techniques
Equine Behavior ProblemsdAround Farriery: Foot Pain in 11 Horses Richard A. Mansmann VMD, PhD, Hon DACVIM-LA a , M. Claire Currie DVM a, b, Maria T. Correa PhD c, Barbara Sherman DVM, PhD, DACVB a, Kurt vom Orde d a
Department of Clinical Sciences, North Carolina State University, Raleigh, NC Centre Equine Practice, Centre Hall, PA c Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC d Chapel Hill, NC b
a b s t r a c t Keywords: Horse Farrier Foot Hoof Pain Behavior
Although foot pain may clearly be the cause when a horse with foot pathology does not tolerate farriery, it may be overlooked or underappreciated as the cause of this behavioral problem when the pathology is mild and/or chronic. In this study, the records of 11 adult horses whose behavior for farriery initially warranted sedation for trimming and shoeing were reviewed. All 11 horses had a history of chronic lameness that was mild to moderate, but foot pain was the presenting complaint in only seven horses - all with chronic laminitis. The other four horses had abnormal foot conformation (long-toe, lowheel, or “club foot), but the lameness had not been attributed to the foot. All 11 horses showed improvement in gait with corrective trimming and shoeing. In each case, sedation for farriery could be discontinued after one to six visits, concurrent with the improvements in gait and foot pathology. On the basis of the survey results from 17 professional farriers, an ethogram of farriery-related undesirable horse behavior was developed. Ó 2011 Elsevier Inc. All rights reserved.
1. Introduction It should be self-evident that a horse with foot pain might be uncooperative for farriery work. Farriery requires the horse to stand on three feet while the fourth foot is lifted for hoof care. Thus, the load on the other three limbs, particularly the contralateral and diagonal limbs, is increased for the duration the fourth foot is raised. If one or more of those limbs is painful, this extra load can become intolerable. Farriery also involves variable amounts of compression, tension, twisting, and concussion on the hoof when the shoe and nails are removed, the hoof is trimmed, and the shoe is replaced. Routine farriery directly involves only the keratinized (i.e., insensitive) structures of the hoof, Current address: Richard A. Mansmann, VMD, PhD, Equine Podiatry and Rehabilitation Mobile Practice, Chapel Hill, NC. Corresponding author at: Richard A. Mansmann, VMD, PhD, Hon DACVIM-LA, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606. E-mail address: [email protected] (R.A. Mansmann). 0737-0806/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.jevs.2010.11.018
so it is not inherently an uncomfortable procedure. Even so, when digital pathology is present, routine farriery and all it entails can cause the horse to be uncomfortable and uncooperative. With obvious painful foot problems such as acute laminitis or a subsolar/submural abscess, the degree of lameness shown by the horse can be seen as a fairly reliable indicator of the degree of care needed when trimming and shoeing. It is entirely understandable that a horse with severe foot pain might be defensive and uncooperative toward the farrier, and perhaps even unpleasant with sufficient irritation. In such cases, the use of sedation or regional anesthesia (e.g., low palmar nerve block) may be the most practical and humane approach to addressing the horse’s farriery needs. The problem arises when the existence and amount of pain is not obvious, such as when a lameness is mild, chronic, inconsistent, or has not been localized to the foot or even to a single limb. In such instances, it can be difficult to determine whether the uncooperative behavior of the horse around the farrier is the result of foot pain or whether
R.A. Mansmann et al. / Journal of Equine Veterinary Science 31 (2011) 44-48
there is a possibility of another explanation. Other causes proposed include inadequate training, lack of discipline or improper restraint by the owner/handler, and a bad attitude toward people in general and farriers in particular as a result of a previous painful experience or reprimand. Most horses tolerate farriery after initial training when young by allowing the feet to be lifted and handled in a typical manner. With training, even horses with a mild to moderate lameness generally endure farriery if it is done with care; however, some may not be able to tolerate the pain, the reason for which may not be clear. It is our belief that some of these horses that are uncooperative have foot pain which has not been recognized or not been adequately addressed. This conclusion was drawn while observing the following: (1) many of these horses have hoof conformational abnormalities and a history of lameness; and (2) initial sedation for the purpose of farriery is no longer needed as the hoof problem improves in response to corrective trimming and shoeing. The purpose of the present study was to document these observations by collecting the clinical findings and outcomes for horses that were initially uncooperative for farriery necessitating sedation at least once, but then no longer required sedation as the feet responded to corrective trimming and shoeing. Additionally, we wanted to examine the number of times sedation was required by the horses for farriery so as to determine whether there was any association with the type of digital pathology present and the severity and duration of the lameness. We also wanted to document the types of behaviors shown by these horses toward the farrier that were considered uncooperative or unsafe for the farrier to work on the feet. An ethogram, which is a catalog of discrete behaviors typically used by a species, was developed as part of this study [1]. Ethograms have been developed for other aspects of equine behavior, such as the natural behavior of horses [2,3], stress-related behaviors in therapeutic riding horses [4], and the assessment of pain after major surgery [5]. Therefore, we produced one ethogram for uncooperative behaviors relating to farriery work. It is our goal that in publishing this observational study and ethogram, the interpretation of uncooperative behaviors can be expanded to specifically include the possibility of foot pain or other source of discomfort, and not be simply labeled as “bad behavior.” 2. Materials and Methods 2.1. Sedation for Farriery This retrospective study referenced the medical records for horses presented to the Equine Podiatry and Rehabilitation Service of North Carolina State University College of Veterinary Medicine over a 2-year period (2006-2008). Initially all the horses that required sedation for the farriery owing to their uncooperative or unsafe behavior around the farrier were included in the study. Horses aged <2 years were excluded from the study to avoid temporary or otherwise confounding behaviors that might primarily be explained by immaturity or early training; mature horses with incomplete records were also excluded. The compiled information included signalment, presenting complaint,
45
duration of complaint, the number of farriery visits conducted at the Equine Podiatry and Rehabilitation Service, the number of times sedation was required for farriery, and the outcome in terms of soundness. Because of the small number of horses that met the study criteria, no statistical analysis was performed. 2.2. Ethogram A one-page survey was sent to professional farriers in North Carolina regarding the types of poor behavior that might be shown by a horse during routine farriery work requiring the farrier to have the horse sedated, or refuse to work on the horse. On the basis of the responses, an ethogram was developed for farriery-related difficult behaviors in horses. 3. Results 3.1. Sedation for Farriery A total of 11 horses met the study criteria. Details are summarized in Table 1. Sedation in all cases included intravenous injection of detomidine hydrochloride (Dormosedan, Pfizer Animal Health, Exton, PA, USA) at the recommended dosage of 20 to 40 mg/kg bodyweight, to effect. The feet of all horses were trimmed and shod by the same experienced farrier (KVO). The study group included adult amateur performance horses, retired riding horses, and rescued horses. The various breeds represented in the study were consistent with the general clinic population. The age of these horses ranged from 6 to 21 years; the average age was 12 years. All 11 horses were presented because of lameness; foot pain was the presenting complaint or recognized by the owner in only seven horses, all of which had a history of laminitis. The remaining four horses each had an abnormal foot conformation (long-toe, low-heel [three horses]; or “club foot” [one horse]), but the lameness had not been localized to the foot. The degree of lameness at initial presentation varied among the study group; one consistent feature was that the lameness was chronic, ranging from months to years in duration. In all 11 horses, sedation for farriery was discontinued after one to more than three times; in seven horses, sedation was required for farriery only once or twice and in four on three or more occasions. There did not appear to be any clear association between duration of lameness and the number of times sedation was needed for farriery. Four of the seven horses requiring sedation only once or twice had been lame for a few months, but another two of these seven horses had been lame for several years. There also did not appear to be any clear association with age, breed, gender, presenting complaint, or lameness grade and the need for sedation. All 11 horses showed improvement in their lameness with corrective trimming and shoeing. Eight horses were able to resume some riding activities and two of the remaining three horses were normal enough to begin ground work. The remaining one horse in the study was pasture sound.
3.2. Ethogram Survey responses were obtained from 17 farriers. The ethogram of farriery-related poor behavior in horses is summarized in Table 2. The specific behaviors were generally categorized as either defensive/evasive or offensive/aggressive. 4. Discussion
WB, Warmblood; TB, Thoroughbred; QH, Quarter Horse; TWH, Tennessee Walking Horse; LTLH, long-toe, low-heel foot shape; WLD, white line disease; RF, right forelimb. Lameness grade: degree of lameness, scored on a scale from 1 (mild) to 5 (severe). Lameness duration: length of time lameness present before presentation. Sedation required: number of farriery visits when sedation was required for farriery.
3 2 1 1 3 2 2 6 1 1 4 5 4 11 6 6 >6 8 5 >4 LTLH, thrush, navicular disease, negative palmar angle; grade 2/5 at trot LTLH, thin soles, WLD; not graded Laminitis, WLD, foot abscesses; not graded LTLH, thin soles, hoof cracks, navicular disease; grade 2/5 occasionally Laminitis in all 4 feet; grade 3/5 at walk Laminitis, thin soles, seromas at toes; not graded Club foot, abscesses; grade 2/5 at trot Laminitis, WLD; grade 4/5 at walk Laminitis, club foot in RF; grade 2/5 at trot Laminitis; grade 3/5 at walk 6-year-old WB gelding 12-year-old WB gelding 14-year-old TB mare 11-year-old TB gelding 17-year-old Paso Fino gelding 21-year-old QH gelding 6-year-old TB mare 12-year-old QH mare 10-year-old TWH mare 7-year-old Paso Fino mare
7 months At least 3 months 3 months 4.5 years 11 months 8 months Lifetime 1.5 years 3 months 4 months
4 6 Chronic laminitis; grade 3/5 at walk 12-year-old Welsh gelding
6 months
Sedation Required Farriery Visits Lameness Duration Presenting Complaint and Lameness Grade Signalment
Table 1 Clinical findings and outcomes for 11 horses requiring sedation for farriery
Resumed use as school horse, giving 5 lessons/week Sound for light riding Improved In regular work Showing and jumping until died of colic Sound for light riding Used for light riding, still mildly lame on RF Pasture sound Comfortable for ground work Sound for light riding Sound for light riding
R.A. Mansmann et al. / Journal of Equine Veterinary Science 31 (2011) 44-48
Outcome
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All of the horses in this study presented with a history of chronic lameness, and all had well-recognized foot pathology of one type or another. What makes this group of horses interesting is that the presenting complaint and the degree of lameness shown by most horses were not considered sufficiently painful or severe enough to require sedation for the purpose of farriery. Acute laminitis can be very painful and may necessitate sedation or regional anesthesia for initial farriery care, and often by the time laminitis is in the chronic phase, the lameness may be only mild to moderate. The long-toe, low-heel foot conformation, club foot, and white line disease are chronic conditions that typically cause only mild to moderate gait abnormalities. All of the foot problems, described in the horses in this study, are commonly encountered but seldom do horses with these clinical problems require sedation for farriery. It has been stated correctly that pain is an experience, not a physiological event that can be quantitated [6]. It is also well accepted that the experience of pain is highly variable among and between individuals, even with identical stimuli and environments [6]. This was our impression with the horses in this study group. There was neither clear association with age, breed, gender, presenting complaint, nor severity or duration of lameness for either the need for sedation or the number of times sedation was required for farriery. Conditions not expected to be painful appeared to be, based on the behavior of the horses toward the farrier and the clinical response to corrective trimming and shoeing. Although we do not know for sure what an animal is feeling, it has been proposed that pain affects behavior in recognizable ways; the degree of behavioral change correlates with the severity of the pain [6]. Thus, it also seems reasonable to conclude that specific behaviors demonstrated by horses in response to obvious painful stimuli may be indicative of pain in similar circumstances that are less clearly painful. As an example, the response to hoof testers or the farrier’s hammer shown by a horse with acute laminitis can reasonably be interpreted as a sign of pain when demonstrated in a horse with thin soles, crushed heels, lamellar detachment, or some other structural failure of the hoof, although there is less marked response. Horses with joint pain more proximally in the limb, for example in the carpus or tarsus, have also been known to be difficult with the farrier. Typically, these horses are more cooperative when the joint pain has been recognized and addressed by adjusting the position of the limb. Therefore, pain anywhere in the limb and in the axial skeleton can give an individual horse sufficient cause to be uncooperative around a farrier.
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Table 2 Ethogram of farriery-related poor behavior in horses Behavior Defensive/evasive actions Snatching foot away Rearing or backing Fearful Unstill Moving away Offensive/aggressive actions Coming at the farrier Biting Striking or kicking Rude, bad manners Tail lashing
It is unlikely that the need for sedation ended because of improved training or maturity; the clinical history did not indicate past problems with routine foot care in the past since all horses were already trained to accept farriery. Each horse underwent observation at the clinic for only one or two hours, every 4 to 6 weeks, and during these visits no attempt was made by the veterinarian, handler, or farrier to train the horse to stand for the farrier. And although the farrier was patient, with all the horses, it is unlikely that these positive interactions would be enough to change a fixed behavior that was serious enough to require sedation. It is also unlikely that sedation directly contributed to a training effect, because positive behavioral results are not necessarily a result of using tranquilization or sedation [7], especially with the range in number of sedations used (in one to six visits) in the study group. We believe the need for sedation stopped because the therapeutic shoeing resolved the painful feet. Pain is a powerful stimulus and an easily learned response. If the uncooperative behavior of the horse was prompted by the recall of past pain during farriery, then one or two visits using a sedative-analgesic agent, detomidine, may have been sufficient to decrease the anxiety and pain associated with farriery resulting in cooperation on all the subsequent visits. However, in this study, pain in each horse appeared to be the stimulus for the poor behavior, and pain relief appeared to resolve the behavioral problem. In our review of the literature, we could neither find any studies which defined the types of undesirable equine behaviors relating to farriery, nor those that address the possible role of foot pain and the behaviors. The purpose of putting together an ethogram of farriery-related poor equine behaviors was to list the specific behaviors with the goal of an initial investigation and a basis for additional research studies. Clearly, pain is only one possible explanation for these poor behaviors. As mentioned, bad training or handling and the recollection of past pain/punishment in relationship to farriery need to be considered. Even so, pain is an important explanation of why a mature horse might behave poorly around a farrier, and it should be considered first. When it comes to pain, an animal should not have to tolerate it when there are safe and effective sedative and analgesic options. Furthermore, the farrier’s job can be challenging enough without having to deal with an uncooperative and potentially dangerous horse. When managing an abnormal foot, it is even more important that
Description Abruptly removing the foot and leg from the farrier’s placement Escape attempt, suddenly erupting violently Scared and unpredictable, trembling, shaking Refusal to stand still; includes leaning, pulling, other bad manners Escape attempt by moving away from the farrier Aggressively moving into the farrier Biting the farrier’s back when working Deliberate attempt to make contact with the farrier Nipping at the lead shank, stomping, bumping the handler Actively swishing the tail side to side
the farriers should be able to take their time and treat the foot properly. There is little reason to withhold sedation or regional anesthesia when a horse is behaving poorly and possibly unsafely for a necessary clinical procedure. With the availability of detomidine as an oral gel, the veterinarian may choose to dispense a dose of detomidine for farriery when pain and its associated cause have been identified as the reason for the poor behavior of the horse [8]. In our experience and based on our reported finding in this study, sedation can be expected to end the root cause of the pain if satisfactorily addressed. In conclusion, it is hoped that this study can be added to the new emphasis on better understanding of equine pain, its expressions, and causes [9]. It is also hoped that the study findings and ethogram help veterinarians and farriers to better interpret and understand the poor behaviors shown by horses around farriers. These behaviors may simply be the result of bad training, improper handling, or the recall of past pain/punishment. However, our findings propose that foot pain or other musculoskeletal pain should be considered an important rule out by a comprehensive physical examination before assigning the horse to the position of “bad” or “spoiled” when pain management is the better approach. Equine behavior that is unsafe around people and other horses cannot be tolerated, and a behavior that makes the farrier’s job more difficult is also unacceptable. We must take care not to forget the possible role of pain, either past or present, in rousing the horse’s behavior. To paraphrase the ethical maxim taught to all medical students: first, consider pain. Acknowledgments The authors thank Drs. Margaret Gruen, Peter Cowen, and Ms. Patricia A. Mansmann for their assistance and Julie Davis with technical help with this study, as well as all the farriers who participated. The authors also acknowledge the editorial input of Christine King, BVSc, MACVSc, MVetClinStud, and are grateful for partial funding from the NCVMF Gallop of Honor Podiatry Fund. References [1] Ethogram. Wikipedia, 2010. Available at: http://en.wikipedia.org/ wiki/Ethogram. [2] McDonnell S. A practical field guide to horse behavior: the equid ethogram. Lexington, KY: The Blood Horse Inc.; 2003.
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