Evidence of the development of ‘domain‐restricted’ expertise in the recognition of asymmetric motion characteristics of hindlimb lameness in the horse

Reasons for performing study: Visual assessment of horses' movements is subjective, affected by bias and dependent on the level of experience of the assessor. However, to date there are no data available on the ability of the human visual system to recognise (a)symmetry in moving objects. Objectives: To investigate, using visual lameness assessment, the limits of human perception and the ability of experienced and nonexperienced individuals to detect asymmetry in 2 moving objects simulating hindlimb lameness in the horse. Methods: Twelve experienced individuals (equine and small animal clinicians), and 24 nonexperienced individuals (undergraduate veterinary students) were presented with computer simulations showing 2 ‘tuber coxae markers’ created using data from both lame and nonperceptibly lame horses, as well as artificial data based on a sine wave. Individuals were asked to classify as symmetrical or asymmetrical, and then rank based on the grade of perceived asymmetry. Repeatability and learning effect were evaluated by repeating the tests on a subset of subjects. Results: The threshold for detection of movement asymmetry was found to be approximately 25% difference in amplitude between the 2 moving objects for all individuals. There was no significant difference between experienced and nonexperienced individuals in the ability to detect asymmetry in the simulations based on artificial data. However, the percentage of correct answers was higher for experienced compared to nonexperienced individuals for simulations based on data from real lame horses. Conclusions: There was a significant difference between experienced and nonexperienced individuals in the ability to identify asymmetric movement based on the pattern seen in a lame horse, as opposed to an artificial pattern for which all individuals showed similar performance. Potential relevance: The study provides the basis for the development of computer simulations that could aid in training veterinarians in the diagnosis of lameness and, even, the objective assessment of expertise in this field.     

The range and prevalence of pathological abnormalities associated with lameness in working horses from developing countries

Reasons for performing study: Lameness is highly prevalent in working horses, but published reports on the associated pathological abnormalities are lacking. With over 42 million horses in developing countries and the majority used for work, lameness has major welfare implications. Objectives: To describe the range and prevalence of pathological abnormalities associated with lameness in working horses. Methods: A standard lameness assessment was adapted for field use in working equids. Data on pathological abnormalities and pain responses in the feet, limbs and spine were collected through observation, palpation, manipulations and gait assessment in working horses from India (n = 110) and Pakistan (n = 117). Lameness at the walk was scored on a scale of 0–4 (sound‐nonweightbearing). Results: All horses examined were lame. Overall, 98% showed a gait abnormality in all 4 limbs and 87% had at least one limb scoring 3 or 4 on the lameness scale. Multiple pathological abnormalities within each limb were associated with lameness, with similar results in both countries. Chronic foot pathology was seen in every horse; 94% horses showed signs of chronic joint disease; 83% had digital flexor tendonitis in at least one limb. Lameness and pathological abnormalities were associated with specific pain responses in the feet, limbs and spine. Conclusions: The extremely high prevalence of multilimb lameness and its association with pain is of great concern. The multiple pathological abnormalities present in working horses makes lameness complex to address. Potential relevance: The results of this detailed study of lameness should facilitate the identification of risk factors and the implementation of interventions to reduce the prevalence of lameness in working equids.     

Comparison of an inertial sensor system of lameness quantification with subjective lameness evaluation

Reasons for performing study: Subjective evaluation of mild lameness has been shown to have poor interobserver reliability. Traditional methods of objective lameness evaluation require specialised conditions and equipment. Wireless inertial sensor systems have been developed to allow for simple, rapid, objective lameness detection in horses trotted over ground. Objective: The purpose of this study was to compare the sensitivities of an inertial sensor system and subjective evaluation performed by experienced equine practitioners at detecting lameness in horses. We hypothesised that the inertial sensor system would identify lameness at a lower level of sole pressure than a consensus of 3 experienced equine veterinarians. Methods: Fifteen horses were fitted with special shoes that allowed for lameness induction via sole pressure. Horses were simultaneously evaluated by 3 equine veterinarians and a wireless inertial sensor system. Horses were subjected to multiple trials: 1) before inserting the screw; 2) after inserting the screw to just touch the sole; and 3) after tightening the screw in half turn increments. The number of screw turns required for lameness identification in the correct limb by the inertial sensors and by consensus of 3 equine veterinarians was compared using the Wilcoxon test. Results: The inertial sensor system selected the limb with the induced lameness after fewer screw turns than did the 3 veterinarians (P<0.0001). The inertial sensor system selected the correct limb before the 3 veterinarians in 35 trials (58.33%), the evaluators selected the correct limb before the inertial sensors in 5 trials (8.33%), and in 20 trials (33.33%) they selected the correct limb at the same time. Potential relevance: The inertial sensor system was able to identify lameness at a lower level of sole pressure than the consensus of 3 equine veterinarians. The inertial sensor system may be an effective aid to lameness localisation in clinical cases.     

Repeatability of subjective evaluation of lameness in horses

Reasons for performing study: Previous studies have suggested that agreement between equine veterinarians subjectively evaluating lameness in horses is low. These studies were limited to small numbers of horses, evaluating movement on the treadmill or to evaluating previously‐recorded videotape. Objectives: To estimate agreement between equine practitioners performing lameness evaluations in horses in the live, over ground setting. Methods: 131 mature horses were evaluated for lameness by 2–5 clinicians (mean 3.2) with a weighted‐average of 18.7 years of experience. Clinicians graded each limb using the AAEP lameness scale by first watching the horse trot in a straight line only and then after full lameness evaluation. Agreement was estimated by calculation of Fleiss' (κ). Evaluators agreed if they picked the same limb as lame or not lame regardless of the severity of perceived lameness. Results: After only evaluating the horse trot in a straight line clinicians agreed whether a limb was lame or not 76.6% of the time (κ= 0.44). After full lameness evaluation clinicians agreed whether a limb was lame or not 72.9% of the time (κ= 0.45). Agreement on forelimb lameness was slightly higher than on hindlimb lameness. When the mean AAEP lameness score was >1.5 clinicians agreed whether or not a limb was lame 93.1% of the time (κ= 0.86), but when the mean score was ≤1.5 they agreed 61.9% (κ= 0.23) of the time. When given the task of picking whether or not the horse was lame and picking the worst limb after full lameness evaluation, clinicians agreed 51.6% (κ= 0.37) of the time. Conclusions: For horses with mild lameness subjective evaluation of lameness is not very reliable. Potential relevance: A search for and the development of more objective and reliable methods of lameness evaluation is justified and should be encouraged and supported.     

Good animal welfare makes economic sense: potential of pig abattoir meat inspection as a welfare surveillance tool

ABSTRACT: During abattoir meat inspection pig carcasses are partially or fully condemned upon detection of disease that poses a risk to public health or welfare conditions that cause animal suffering e.g. fractures. This incurs direct financial losses to producers and processors. Other health and welfare-related conditions may not result in condemnation but can necessitate 'trimming' of the carcass e.g. bruising, and result in financial losses to the processor. Since animal health is a component of animal welfare these represent a clear link between suboptimal pig welfare and financial losses to the pig industry.Meat inspection data can be used to inform herd health programmes, thereby reducing the risk of injury and disease and improving production efficiency. Furthermore, meat inspection has the potential to contribute to surveillance of animal welfare. Such data could contribute to reduced losses to producers and processors through lower rates of carcass condemnations, trimming and downgrading in conjunction with higher pig welfare standards on farm. Currently meat inspection data are under-utilised in the EU, even as a means of informing herd health programmes. This includes the island of Ireland but particularly the Republic.This review describes the current situation with regard to meat inspection regulation, method, data capture and utilisation across the EU, with special reference to the island of Ireland. It also describes the financial losses arising from poor animal welfare (and health) on farms. This review seeks to contribute to efforts to evaluate the role of meat inspection as a surveillance tool for animal welfare on-farm, using pigs as a case example.     

Comparison of lameness outcomes in horses with acute or chronic digital lameness that underwent magnetic resonance imaging

ABSTRACT

Aims: To compare the outcome, in terms of lameness score or return to athletic function, of horses with acute vs. chronic digital lameness that underwent magnetic resonance imaging (MRI) of the distal limb and to compare the proportion of horses that received intra-articular therapy of the distal interphalangeal (DIP) joint and pattern of diagnostic analgesia in these groups.

Methods: This is a retrospective study of horses (n?=?95) with acute (≤12 weeks; n?=?46) or chronic (>12 weeks; n?=?49) digital lameness that underwent MRI of the distal limb from 2009–2016, at two equine referral centres in the USA. Criteria for inclusion in the study were that a majority of lameness localised distal to the fetlock, and that lameness assessments for ≥12 months following MRI could be obtained from the medical record or the owner could be interviewed regarding their horse's athletic function. Outcome was characterised by an improvement score where 2?=?return to work at a previous or higher level or lameness improved by one grade or more, 1?=?return to work at a lower level or lameness improved by less than one grade, and 0?=?did not return to work or lameness grade worsened. Whether horses had received intra-articular therapy of the DIP joint and the pattern of diagnostic analgesia prior to MRI was also obtained from medical records or by interviewing the owner.

Results: There was a difference (p?=?0.004) in the proportion of horses assigned to improvement scores of 0, 1 and 2 between horses with acute or chronic lameness. There was no evidence of a difference in the likelihood of having received intra-articular therapy of the DIP joint prior to MRI between horses with chronic or acute lameness (p = 0.085). Similarly, there was no evidence of a difference in the pattern of diagnostic analgesia prior to MRI between the two groups (p = 0.94). Eighty-two percent of owners of horses with acute and 62% of those with horses with chronic lameness had a positive opinion of the utility of MRI as a diagnostic modality.

Conclusion: In a population of horses with digital lameness undergoing MRI, a difference in the outcome, in terms of lameness score or return to athletic function was identified between horses with acute lameness compared to those with chronic lameness.

Clinical relevance: Horses with digital lameness that undergo MRI when the lameness is acute may have an improved prognosis due to accurate diagnosis and earlier application of appropriate therapy.     

Analysis of influencing factors of boar claw lesion and lameness

This study aimed to investigate the factors affecting boar claw lesions and lameness. A total of 1299 boars were examined for claw lesions and lameness, including 788 boars reared in individual pens with solid concreted floor (IPS) and 511 boars raised in individual stalls with slatted floor (ISS). Flooring type showed significant impacts on all claw lesion types (P < 0.01). Except for swelling ankle, boar age had significant effects on all other claw lesion types (P < 0.01). In addition, only heel overgrowth and erosion, cracked wall horizontal, heel‐sole crack, dew claws, and toes were significantly related to boar breeds (P < 0.05). Furthermore, IPS lame boars had higher prevalence of lameness in the hind limb (P < 0.05), whereas in ISS lame boars, there were no significant differences in prevalence of lameness between the fore and hind limbs (P > 0.05). Boar lameness was moderately correlated with swelling ankle (Φ = 0.5571). In conclusion, claw lesions can be influenced by flooring type, boar age and breed, and could serve as a predictor for boar lameness.     

Radiographic and scintigraphic evaluation of the third carpal bone of control horses and horses with carpal lameness

We compared the radiographic and scintigraphic findings in the third carpal bone of horses performing different work disciplines and investigated their relationship with lameness. Horses had undergone carpal radiography including acquisition of a dorsoproximal-dorsodistal oblique (DPr-DDiO) image of the distal row of carpal bones and/or scintigraphic examination of the carpi. Cause of lameness, breed, age, and work discipline were recorded. Increased opacity in the third carpal bone was graded, ratio of radiopharmaceutical uptake calculated objectively, and increased radiopharmaceutical uptake graded subjectively. Relationships between radiographic, scintigraphic, and clinical findings were assessed statistically. Increased opacity in the third carpal bone (P = 0.003) and ratio of radiopharmaceutical uptake (P = 0.015) were associated with the work discipline. Increased opacity in the third carpal bone was associated with both increased radiopharmaceutical uptake grade (P = 0.002; rs = 0.59) and ratio of radiopharmaceutical uptake (P = 0.013; rs = 0.46). Increased radiopharmaceutical uptake and increased opacity in the third carpal bone were not always observed concurrently. Lameness related to the middle carpal joint was associated with increased opacity (P < 0.001), ratio of radiopharmaceutical uptake (P = 0.037), and increased radiopharmaceutical uptake grade (P < 0.001). Radiographic and scintigraphic abnormalities were observed in horses performing all disciplines, indicating that high-speed exercise may not be the only factor determining the development of osseous disease in the third carpal bone. Both increased opacity and increased radiopharmaceutical uptake were more likely to be seen in horses with lameness related to the middle carpal joint than in horses with other sources of pain.     

Efficacy of orally administered gabapentin in horses with chronic thoracic limb lameness

ObjectiveTo evaluate the analgesic effects of orally administered gabapentin on horses with chronic thoracic limb lameness.Study designRandomized, crossover design.AnimalsA total of 14 adult horses with chronic thoracic limb lameness.MethodsFollowing baseline measurement of lameness, horses were administered each of four treatments orally in grain: treatment G, gabapentin (20 mg kg^–1) twice daily for 13 doses; treatment F, firocoxib (171 mg once, then 57 mg once daily for six doses); treatment GF, gabapentin and firocoxib at previously stated doses and frequencies; or treatment C, grain only as a control. Treatments were administered in a randomized, crossover design, separated by 2 weeks. Subjective lameness score (SLS), inertial sensor vector sum (VS) calculations, peak vertical ground reaction force (PVGRF) measurements and vertical impulse (VI) calculations were determined immediately prior to each initial treatment dose and 2–4 hours after the final treatment dose for each treatment. Mean change in SLS, VS, PVGRF and VI for each treatment were compared among treatments.ResultsThe rank change in SLS of treatment GF was significantly greater than that of treatments C (p = 0.01) and G (p = 0.01) but not of treatment F (p = 0.08). No differences in VS (p = 0.4), PVGRF (p = 0.4) or VI (p = 0.1) were observed among treatments.Conclusions and clinical relevanceGabapentin, as administered here, did not improve subjective or objective measures of lameness in horses with chronic thoracic limb musculoskeletal pain. Although subjective evaluation identified an improvement in lameness with treatment GF, it was not different from that observed with treatment F. Higher oral dosing and longer treatment regimens of gabapentin may be indicated for the treatment of chronic musculoskeletal pain in horses.     

The effect of induced hindlimb lameness on thoracolumbar kinematics during treadmill locomotion

REASON FOR PERFORMING STUDY: There are no detailed studies describing a relationship between hindlimb lameness and altered motion of the back. OBJECTIVES: To quantify the effect of induced subtle hindlimb lameness on thoracolumbar kinematics in the horse. METHODS: Kinematics of 6 riding horses were measured during walk and trot on a treadmill before and during application of pressure on the sole of the left hindlimb using a well-established sole pressure model. Reflective markers were located at anatomical landmarks on the limbs, back, head and neck for kinematic recordings. Ground reaction forces (GRF) in individual limbs were calculated from kinematics to detect changes in loading of the limbs. RESULTS: When pressure on the sole of the hindlimb was present, horses were judged as lame (grade 2 on the AAEP scale 1-5) by an experienced clinician. No significant unloading of this limb was found in the group of horses (unloading was observed in 4 animals, but was not detectable in the other 2), but statistically significant effects on back kinematics were detected. The overall flexion-extension (FE) range of motion (ROM) of the vertebral column was increased at walk, especially in the thoracic segments. Axial rotation (AR) ROM of the pelvis was also increased. At trot, the FE ROM was decreased only in the segment L3-L5-S3. During the stance phase of the lame limb, the segment T6-T10-T13 was more flexed and the neck was lowered at both gaits; the thoracolumbar segments were more extended at walk and trot. There were no significant changes in the stride length or protraction-retraction angles in any of the limbs. CONCLUSIONS: Subtle hindlimb lameness provoked slight but detectable changes in thoracolumbar kinematics. The subtle lameness induced in this study resulted in hyperextension and increased ROM of the thoracolumbar back, but also in decreased ROM of the lumbosacral segment and rotational motion changes of the pelvis. POTENTIAL RELEVANCE: Even subtle lameness can result in changes in back kinematics, which emphasises the intricate link between limb function and thoracolumbar motion. It may be surmised that, when chronically present, subtle lameness induces back dysfunction.     

奶牛蹄部不同部位温度在跛行诊断中的应用

为了确定应用手持式红外线测温仪筛选奶牛蹄部不同部位的温度用于奶牛跛行的诊断价值,本研究在奶牛修蹄前进行跛行评分,修蹄后用手持式红外线测温仪分别测量奶牛右后蹄系部、右后蹄外侧趾远轴侧蹄壁和右后蹄外侧趾蹄底三角区的温度,分析其与奶牛跛行程度的相关性,并绘制不同部位蹄部温度的ROC曲线,确定其诊断作用和最佳临界值.结果显示,...     

Effect of lameness (hoof disorders) on productivity of Karan Fries crossbred cows

In present study production performance of 96 lame cows was compared with 67 healthy cows. No significant effect of parity and year of calving on milk yield were observed but the effect of season of calving was significant (P < 0.01). Effect of lameness on milk yield at the second, third and fourth months and 305 days was highly significant (P < 0.01), and was also significant (P < 0.05) on lactation yield of the fifth and tenth months. The effect of lameness on monthly and 305‐day milk yield was significant (P < 0.01) only for those cows diagnosed lame before calving and during the first month of lactation. The differences in mean monthly yield were highly significant (P < 0.01) at the second, third and fourth months; and significant (P < 0.05) in the first and fifth months. The loss in the first lactation month of cows which were diagnosed as lame in the second month, was found to be significant (P < 0.05). Thus the yield of the month previous to the diagnosis (sub‐clinical stage) was also affected. A significant (P < 0.01) total loss of 498.95 kg of milk yield was observed during a period of 305 days.     

Subchondral bone cyst of the apical portion of the proximal sesamoid bone as a cause of severe lameness in a Warmblood filly

A 20‐month‐old Warmblood filly was evaluated for acute onset of a nonweightbearing lameness and swelling of the left hindlimb. Clinical and lameness evaluation and diagnostic intrasynovial anaesthesia isolated the lameness to the left hind metatarsophalangeal region. Radiography and ultrasonography revealed a subchondral cystic lesion of the apical portion of the lateral proximal sesamoid bone associated with oedema and synovial effusion of the metatarsophalangeal joint. Arthroscopic surgical debridement of the subchondral cystic lesion resulted in immediate post operative improvement in the lameness score. Rest and controlled exercise achieved complete resolution of the lameness with the filly being able to start training without apparent lameness. Subchondral cystic lesions of the proximal sesamoid bones can be a cause of nonweightbearing lameness. Surgical debridement resulted in complete resolution of the lameness with a favourable outcome in this case.