Vertical pelvic movement asymmetry and lameness location in ipsilateral combined forelimb and hindlimb lameness cases.

BACKGROUND: Compensatory vertical head and pelvis movement asymmetry may occur in trotting horses with a primary cause of lameness in one end of the body due to the weight shifting between limbs, leading to apparent combined forelimb and hindlimb lameness (CFHL). Little is known about CFHL patterns observed with body-mounted inertial sensors (BMIS) and regardless of their underlying mechanisms, compensatory and secondary lameness may complicate the definitive identification of the primary causes of lameness. OBJECTIVE: Determine associations between vertical pelvic movement asymmetry and location of primary lameness in ipsilateral CFHL cases where hindlimb lameness is solely impact or push-off type. STUDY DESIGN: Retrospective cohort. METHODS: From a body-mounted inertial sensor (BMIS) evaluated equine lameness database, we identified cases with a consistent, low-variability ipsilateral impact (IpI) or ipsilateral pushoff (IpP) hindlimb lameness in a straight-line trot and that had definitive diagnoses. Cases were categorised by lameness location to the limb(s), diagnosis, and ratio of the amplitude of forelimb to hindlimb lameness (Forea/Hinda). Differences in the numbers of IpI and IpP cases in these categories were analysed with chi-square tests, effect sizes, and odds ratios. RESULTS: Among the 2375 total lameness cases screened, 49 IpI and 36 IpP cases met the criteria for consistency, low variability, and definitive diagnosis. IpI cases were more likely than IpP cases to have forelimb-only lameness causes when Forea/Hinda >1 (OR = 43, 95% CI = 2.3-798). IpP cases were more likely than IpI cases to have hindlimb-only causes at both Forea/Hinda >1.0 (OR = 20, 95% CI = 2.2-200) and <1.0 (OR = 14, 95% CI = 2.9-66.7). Compared with IpI, IpP cases were more frequently diagnosed with tendon, suspensory ligament, or high-motion joint disorders in hindlimbs (OR = 3.6, 95% CI = 1.1-12.3) and less with unknown causes (OR = 13.2, 95% CI = 3.2-75.2). In IpI cases, positive forelimb regional anaesthesia often reduced hindlimb lameness, whereas in IpP cases, positive hindlimb regional anaesthesia typically lessened forelimb lameness. MAIN LIMITATIONS: Most cases were Quarter Horses. The likelihood of location and cause of lameness may be different for other breeds. CONCLUSIONS: The type of pelvic movement asymmetry observed in IpI and IpP cases is linked to the location and underlying cause of the primary lameness.

Prevalence and clinical significance of increasing head height asymmetry as a measure of forelimb lameness in horses when trotting in a straight line after palmar digital nerve block.

BACKGROUND: Some horses increase in forelimb lameness, measured as vertical head height asymmetry, or differences in maximums and minimums of head heights (HDmax, HDmin), after a palmar digital nerve (PDN) block. The prevalence of this finding, or what it means clinically, has not been reported in peer-reviewed literature. OBJECTIVES: To estimate the prevalence of increasing head height asymmetry after a PDN block and determine if this is associated with cause of forelimb lameness. STUDY DESIGN: Retrospective case series. METHODS: Head height asymmetry, normalised to expected vertical head displacement, from inertial-sensor data collections of all horses evaluated for forelimb lameness while trotting in a straight line at two different clinics were screened for cases that had an initial PDN block and then another more proximal block in the same limb during the same lameness evaluation. Medical records of the screened cases (n = 213) were evaluated to determine the cause of lameness. Prevalence of increasing head height asymmetry was calculated. Differences in lameness amplitude between groups of cases that remained unchanged (Group 1), that increased (Group 2), and that decreased (Group 3) in head height asymmetry before and after the initial PDN block were compared (Kruskal-Wallis). Determination of the location of the cause of lameness and final diagnoses of cases were compared between Group 1 and Group 2 (chi-squared tests of independence). RESULTS: The PDN block increased head height asymmetry at a prevalence of 32.5% (95% CI = 24.5%-41.5%) and 13.8% (95% CI = 7.3%-22.9%), in clinic 1 and 2, respectively. Increasing head height asymmetry after an initial PDN block did not predict localization of the cause of forelimb lameness or specific diagnosis (p = 0.1), other than indicating that it is unlikely to be in the foot (p = 0.02). MAIN LIMITATIONS: Study samples consisted primarily of Warmbloods (clinic 1) and Quarter Horses (clinic 2). Analysis of blocking induced changes was limited to straight line trot only. CONCLUSIONS: Increasing head height asymmetry after PDN block is common during forelimb lameness evaluations. Other than indicating that the cause of lameness is more proximal in the blocked forelimb, this does not help determine the final diagnosis.

Development of Advanced Veterinary Nursing Degrees: Rising Interest Levels for Careers as Advanced Practice Registered Veterinary Nurses.

Strategic planning for the future of veterinary medicine is crucial. The advancement of veterinary nursing is of growing interest and demand. With veterinarians working fewer hours, rising debt to income ratios for veterinary students, underserved rural areas, and career dissatisfaction for veterinary technicians; providing options for the advancement of veterinary nursing will be instrumental in paving the path for the future of veterinary medicine. A graduate veterinary nursing program could provide a platform for the development of an Advanced Practice Registered Veterinary Nurse (APRVN). The APRVN, much like a nurse practitioner and physician assistant, could provide the level of care and responsibility needed to streamline patient assessment and point of care services while maintaining quality patient care and client satisfaction. Utilization of physician extenders offsets physician workload, increases clinical practice growth, and helps to maintain patient retention through allotting more time for education and consultation. Utilization of veterinary nurses in a similar manner may provide similar benefits. To evaluate the interest level for the development of a veterinary nurse graduate program, a survey was distributed to learn more about the kinds of opportunities current and future veterinary nursing professionals in the field are interested in pursuing to support their own career growth. With a total of 703 respondents, the survey indicated 80.06% were in favor of the development of the APRVN through a veterinary nurse graduate program.

Comparison of results for body-mounted inertial sensor assessment with final lameness determination in 1,224 equids.

OBJECTIVE: To compare results for initial body-mounted inertial sensor (BMIS) measurement of lameness in equids trotting in a straight line with definitive findings after full lameness evaluation. ANIMALS: 1,224 equids. PROCEDURES: Lameness measured with BMIS equipment while trotting in a straight line was classified into categories of none, forelimb only, hind limb only, and 8 patterns of combined forelimb and hind limb lameness (CFHL). Definitive findings after full lameness evaluation were established in most horses and classified into types (no lameness, forelimb- or hind limb-only lameness, CFHL, or lameness not localized to the limbs). Observed proportions of lameness type in equids with definitive findings for each initial BMIS-assessed category were compared with hypothetical expected proportions through χ2 goodness-of-fit analysis. RESULTS: The most common initial BMIS-assessed lameness category was CFHL (693/1,224 [56.6%]), but this was the least common definitive finding (94/ 862 [10.9%]). The observed frequency of no lameness after full lameness evaluation was greater than expected only when initial BMIS measurements indicated no lameness. The observed frequency of forelimb-only lameness was greater than expected when initially measured as forelimb-only lameness and for CFHL categories consistent with the diagonal movement principle of compensatory lameness. Observed frequency of hind limb-only lameness was greater than expected when initially measured as hind limb-only lameness and for CFHL categories consistent with the sagittal movement principle of compensatory lameness. Equids initially assessed as having no lameness had the highest (103/112 [92%]) and those assessed as CFHL pattern 7 (forelimb with contralateral hind limb impact-only lameness) had the lowest (36/66 [55%]) rates of definitive findings. CONCLUSIONS AND CLINICAL RELEVANCE: In equids, results of initial straight-line trotting evaluations with a BMIS system did not necessarily match definitive findings but may be useful in planning the remaining lameness evaluation.

Effect of induced hindlimb length difference on body-mounted inertial sensor measures used to evaluate hindlimb lameness in horses.

This study has investigated the immediate effect of induced hindlimb length difference on hindlimb lameness measured as differences in minimum (Pmin) and maximum (Pmax) pelvic heights in 16 horses trotting in a straight line and lungeing on both hard and soft surfaces with body-mounted inertial sensors. Hindlimb length differences were induced by applying an Easyboot Glue-on shoe to one hindlimb. Changes in Pmin and Pmax with induced hindlimb length difference were assessed with a two-way repeated-measures ANOVA with trial (straight, lunge with inside limb elevation, lunge with outside limb elevation) and surface (hard, soft) as within-subject factors. Change in Pmin, indicating an impact-type lameness, in the hind limb with the elevation, was significant in both the straight line and while lunging on both hard and soft surfaces. Change in Pmax, indicating pushoff-type lameness, in the opposite, non-elevated hind limb, was significant when trotting in a straight line but not while lunging.

An attempt to detect lameness in galloping horses by use of body-mounted inertial sensors.

OBJECTIVE To evaluate head, pelvic, and limb movement to detect lameness in galloping horses. ANIMALS 12 Thoroughbreds. PROCEDURES Movement data were collected with inertial sensors mounted on the head, pelvis, and limbs of horses trotting and galloping in a straight line before and after induction of forelimb and hind limb lameness by use of sole pressure. Successful induction of lameness was determined by measurement of asymmetric vertical head and pelvic movement during trotting. Differences in gallop strides before and after induction of lameness were evaluated with paired-sample statistical analysis and neural network training and testing. Variables included maximum, minimum, range, and time indices of vertical head and pelvic acceleration, head rotation in the sagittal plane, pelvic rotation in the frontal plane, limb contact intervals, stride durations, and limb lead preference. Difference between median standardized gallop strides for each limb lead before and after induction of lameness was calculated as the sum of squared differences at each time index and assessed with a 2-way ANOVA. RESULTS Head and pelvic acceleration and rotation, limb timing, stride duration measurements, and limb lead preference during galloping were not significantly different before and after induction of lameness in the forelimb or hind limb. Differences between limb leads before induction of lameness were similar to or greater than differences within limb leads before and after lameness induction. CONCLUSIONS AND CLINICAL RELEVANCE Galloping horses maintained asymmetry of head, pelvic, and limb motion between limb leads that was unrelated to lameness.

Comparison of a body-mounted inertial sensor system-based method with subjective evaluation for detection of lameness in horses.

OBJECTIVE: To compare data obtained with an inertial sensor system with results of subjective lameness examinations performed by 3 experienced equine veterinarians for evaluation of lameness in horses. ANIMALS: 106 horses. PROCEDURES: Horses were evaluated for lameness with a body-mounted inertial sensor system during trotting in a straight line and via subjective evaluation by 3 experienced equine practitioners who performed complete lameness examinations including lunging in a circle and limb flexion tests. Agreement among evaluators regarding results of subjective evaluations and correlations and agreements between various inertial sensor measures and results of subjective lameness evaluations were determined via calculation of Fleiss' κ statistic, regression analysis, and calculation of 95% prediction intervals. RESULTS: Evaluators agreed on classification of horses into 3 mutually exclusive lameness categories (right limb lameness severity greater than left limb lameness severity, left limb lameness severity greater than right limb lameness severity, or equal right and left limb lameness severity) for 58.8% (κ = 0.37) and 54.7% (κ = 0.31) of horses for forelimb and hind limb lameness, respectively. All inertial sensor measures for forelimb and hind limb lameness were positively and significantly correlated with results of subjective evaluations. Agreement between inertial sensors measures and results of subjective evaluations was fair to moderate for forelimb lameness and slight to fair for hind limb lameness. CONCLUSIONS AND CLINICAL RELEVANCE: Results of lameness evaluation of horses with an inertial sensor system and via subjective lameness examinations were significantly correlated but did not have strong agreement. Inertial sensor-based evaluation may augment but not replace subjective lameness examination of horses.

Comparison of an inertial sensor system with a stationary force plate for evaluation of horses with bilateral forelimb lameness.

OBJECTIVE: To assess the analytic sensitivity of an inertial sensor system for detection of the more severely affected forelimb in horses with bilateral lameness. ANIMALS: 18 adult horses with forelimb lameness. PROCEDURES: Horses were fitted with inertial sensors and evaluated for lameness with a stationary force plate as they were trotted in a straight line. Inertial sensor-derived measurements for vertical head movement asymmetry (HMA) and vector sum (VS) of maximum and minimum head height differences between right and left halves of the stride were used to predict differences in mean peak vertical force (PVF) as a percentage of body weight between the right and left forelimbs. Repeatability was compared by calculation of the intraclass correlation coefficient (ICC) for each variable. Correct classification percentages for the lamer forelimb were determined by use of a stationary force plate as the standard. RESULTS: SEs of the prediction of difference in PVF between the right and left forelimbs from HMA and VS were 6.1% and 5.2%, respectively. Head movement asymmetry (ICC, 0.72) was less repeatable than PVF (ICC, 0.86) and VS (ICC, 0.84). Associations were positive and significant between HMA (R(2) = 0.73) and VS (R(2) = 0.81) and the difference in PVF between the right and left forelimbs. Correct classification percentages for HMA and VS for detecting the lamer forelimb were 83.3% and 77.8%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that an inertial sensor system to measure vertical asymmetry (HMA and VS) due to forelimb lameness in horses trotting in a straight line has adequate analytic sensitivity for clinical use. Additional studies are required to assess specificity of the system.

Assessment of repeatability of a wireless, inertial sensor-based lameness evaluation system for horses.

OBJECTIVE: To determine repeatability of a wireless, inertial sensor-based lameness evaluation system in horses. ANIMALS: 236 horses. PROCEDURES: Horses were from 2 to 29 years of age and of various breeds and lameness disposition. All horses were instrumented with a wireless, inertial sensor-based motion analysis system on the head (accelerometer), pelvis (midline croup region [accelerometer]), and right forelimb (gyroscope) before evaluation in 2 consecutive trials, approximately 5 minutes apart, as the horse was trotted in a straight line. Signal-processing algorithms generated overall trial asymmetry measures for vertical head and pelvic movement and stride-by-stride differences in head and pelvic maximum and minimum positions between right and left sides of each stride. Repeatability was determined, and trial difference was determined for groups of horses with various numbers of strides for which data were collected per trial. RESULTS: Inertial sensor-based measures of torso movement asymmetry were repeatable. Repeatability for measures of torso asymmetry for determination of hind limb lameness was slightly greater than that for forelimb lameness. Collecting large numbers of strides degraded stride-to-stride repeatability but did not degrade intertrial repeatability. CONCLUSIONS AND CLINICAL RELEVANCE: The inertial sensor system used to measure asymmetry of head and pelvic movement as an aid in the detection and evaluation of lameness in horses trotting in a straight line was sufficiently repeatable to investigate for clinical use.

An in vitro biomechanical comparison of dynamic condylar screw plate combined with a dorsal plate and double plate fixation of distal diaphyseal radial osteotomies in adult horses.

OBJECTIVE: To compare stiffness and strength of a dynamic condylar screw plate combined with dorsal broad dynamic compression plate (DCS-bDCP) fixation with double broad dynamic compression plate (dbDCP) fixation used to repair oblique distal fractures of adult equine radii. STUDY DESIGN: Experimental. SAMPLE POPULATION: Adult equine radii (n=10 pair). METHODS: An unconstrained three-dimensional loading-measurement system was used to determine stiffness of a 50 mm long intact, and then DCS-bDCP or dbDCP-plated osteotomized/ostectomized segment of radii when subjected to a nondestructive sequence of compression, torsion, and lateral-to-medial (LM), medial-to-lateral (ML), cranial-to-caudal (CrCa), and caudal-to-cranial (CaCr) bending. Uniform load over the entire length of construct identified its weakest characteristics during torsion and LM and CrCa bending to failure. RESULTS: No difference was observed between osteotomized/ostectomized DCS-bDCP and dbDCP construct stiffness for all 6 loading modes, and strength for all 3 failure loads. Ostectomized DCS-bDCP and dbDCP construct stiffness was significantly lower than osteotomized radii, the latter approaching intact for axial, LM, and CrCa bending. Most frequent failure was bone fracture through exit site of a screw located adjacent to osteotomy/ostectomy. CONCLUSIONS: DCS-DCP and dbDCP constructs had comparable strength and stiffness when repairing osteotomies/ostectomies in equine adult radius bone. Fracture reduction increased stiffness that approached intact bone for loads that placed the unplated side in compression. CLINICAL RELEVANCE: DCS-bDCP and dbDCP constructs are comparable in stiffness and strength when applied to oblique distal diaphyseal osteotomies/ostectomies in equine radius bone. However, the DCS's localized effect on distal epiphyseal structure because of additional bone removal remains to be investigated under in vivo articular loading conditions.

Evaluation of intraoperative culture results as a predictor for short-term incisional complications in 49 horses undergoing abdominal surgery.

This study evaluated bacterial isolates obtained during abdominal surgery and their relationship to short-term incisional complications. Samples of peritoneal fluid and from resection and/or enterotomy sites from 49 horses were cultured, with 96% having at least one positive culture result. The most common isolates were Escherichia coli, Streptococcus spp, and Enterococcus spp. Horses with small intestinal resections were more likely to grow obligate anaerobes and enteric organisms. Horses with small intestinal lesions (+/- resection) were more likely to grow enteric organisms and less likely to grow non-enteric organisms. Horses without enterotomy or resection procedures were more likely to grow 3 isolates and did not grow obligate anaerobes. The continued incisional drainage rate was 10%. Horses with preoperative peripheral leukocyte counts >8,500 cells/ul were more likely to develop incisional drainage. Many horses undergoing abdominal surgery may have positive intraoperative culture results. Our results did not provide evidence for the routine use of intraoperative culture to predict short-term incisional complications. Further studies are needed to evaluate the value of intraoperative culture in horses at high risk for incisional complications.

Effectiveness of administration of phenylbutazone alone or concurrent administration of phenylbutazone and flunixin meglumine to alleviate lameness in horses.

OBJECTIVE: To determine the effectiveness of administering multiple doses of phenylbutazone alone or a combination of phenylbutazone and flunixin meglumine to alleviate lameness in horses. ANIMALS: 29 adult horses with naturally occurring forelimb and hind limb lameness. PROCEDURES: Lameness evaluations were performed by use of kinematic evaluation while horses were trotting on a treadmill. Lameness evaluations were performed before and 12 hours after administration of 2 nonsteroidal anti-inflammatory drug (NSAID) treatment regimens. Phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days, or phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days in combination with flunixin meglumine administered at 1.1 mg/kg, IV, every 12 hours for 5 days. RESULTS: Alleviation of lameness was greater after administration of the combination of NSAIDs than after oral administration of phenylbutazone alone. Improvement in horses after a combination of NSAIDs did not completely mask lameness. Five horses did not improve after either NSAID treatment regimen. All posttreatment plasma concentrations of NSAIDs were less than those currently allowed by the United States Equestrian Federation Inc for a single NSAID. One horse administered the combination NSAID regimen died of acute necrotizing colitis during the study. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of a combination of NSAIDs at the dosages and intervals used in the study reported here alleviated the lameness condition more effectively than did oral administration of phenylbutazone alone. This may attract use of combinations of NSAIDs to increase performance despite potential toxic adverse effects.

Preliminary anatomic investigation of three approaches to the equine cranium and brain for limited craniectomy procedures.

OBJECTIVE: To describe surgical approaches to the equine cranium and brain for limited craniectomy. STUDY DESIGN: Descriptive anatomic study. SAMPLE POPULATION: Equine cadavers (n=7). METHODS: Head and neck sections from cadavers were used to establish techniques for exposing areas of the equine brain. Three basic approaches were used: rostrotentorial, suboccipital, and transfrontal. Techniques were adapted from small animal descriptions and modified to account for anatomic differences. RESULTS: Descriptions of the rostrotentorial, suboccipital, and transfrontal approaches to the equine cranium and brain were defined. CONCLUSIONS: Dorsal, caudal, lateral, and rostral aspects of the cranium and underlying cerebral cortex can be accessed using the rostrotentorial, suboccipital, and transfrontal approaches. Access to the dorsal, dorsolateral, and rostral aspects of the cerebral cortex is uncomplicated and more superficial compared with access to the extreme caudolateral cerebrum and cerebellum, which is complicated by the location of the transverse and temporal sinuses and deep exposure. CLINICAL RELEVANCE: Many cases of equine brain disorders involve intracranial abscessation or hematoma formation because of trauma. Components of therapy may include microbial culture and surgical drainage or decompression of the affected area through limited craniectomy procedures. Increased use of advanced imaging in equine brain disease has resulted in earlier diagnosis and more precise lesion localization. Subsequently, the number of horses likely to improve with limited surgical intervention has increased. When surgery is indicated, descriptions of surgical approaches to the equine cranium and brain provide important information.

Effects of intra-articular botulinum toxin type A in an equine model of acute synovitis: a pilot study.

OBJECTIVE: To test the hypothesis that botulinum toxin type A (BoNT-A) can attenuate lameness associated with acute synovitis in an equine model. DESIGN: Four horses 2-6 yrs of age with clinically normal carpi were studied for 15 days. Kinematic gait analysis and clinical measures of lameness were conducted before and after experimental interventions. Horses were randomly assigned to either placebo (saline) or treatment (BoNT-A) groups. On day 0 of the intervention, 50 units of BoNT-A or an equivalent volume of saline (0.09%) was given into the middle carpal joints. On day 14, acute synovitis was induced with intra-articular injection of recombinant equine interleukin-1 beta (IL-1 beta) 100 ng. Synovial fluid, clinical evaluation of lameness, and kinematic gait analysis were evaluated on day 15. RESULTS: Synovitis was observed on histology and cytology in all horses after IL-1 beta, indicating acute suppurative inflammation. In the BoNT-A group, one horse developed lameness, whereas the other demonstrated no change in baseline gait evaluation. No adverse effects were observed in joints injected with BoNT-A or with saline alone. CONCLUSIONS: Our findings support the idea that BoNT-A can attenuate lameness in an equine model of acute synovitis. Our findings further suggest that BoNT-A might be a potential new treatment for painful arthritis; this warrants further study.

Intracranial abscess caused by Rhodococcus equi infection in a foal.

CASE DESCRIPTION: A 4-month-old Missouri Fox Trotter colt was examined for a 5-week history of head tilt after treatment for suspected pulmonary Rhodococcus equi infection. CLINICAL FINDINGS: Computed tomography revealed osteolysis of the occipital, temporal, and caudal portion of the parietal bones of the left side of the cranium. A soft tissue mass compressing the occipital region of the cerebral cortex and cerebellum was associated with the osteolytic bone. TREATMENT AND OUTCOME: A rostrotentorial-suboccipital craniectomy approach was performed to remove fragmented occipital bone, debulk the intracranial mass, and obtain tissue samples for histologic examination and bacterial culture. All neurologic deficits improved substantially within 3 days after surgery. Bacterial culture of the resected soft tissue and bone fragments yielded R equi. CLINICAL RELEVANCE: Intracranial surgery in veterinary medicine has been limited to dogs and cats; however, in select cases, extrapolation of surgical techniques used in humans and small animals can assist with intracranial procedures in horses.

Use of gyroscopic sensors for objective evaluation of trimming and shoeing to alter time between heel and toe lift-off at end of the stance phase in horses walking and trotting on a treadmill.

OBJECTIVE: To determine whether a shoe with an axialcontoured lateral branch would induce greater lateral roll of the forelimb hoof during the time between heel and toe lift-off at end of the stance phase (breakover). Animals-10 adult horses. PROCEDURE: A gyroscopic transducer was placed on the hoof of the right forelimb and connected to a transmitter. Data on hoof angular velocity were collected as each horse walked and trotted on a treadmill before (treatment 1, no trim-no shoe) and after 2 treatments by a farrier (treatment 2, trim-standard shoe; and treatment 3, trim-contoured shoe). Data were converted to hoof angles by mathematical integration. Breakover duration was divided into 4 segments, and hoof angles in 3 planes (pitch, roll, and yaw) were calculated at the end of each segment. Multivariable ANOVA was performed to detect differences among treatments and gaits. RESULTS: Trimming and shoeing with a shoe with contoured lateral branches induced greater mean lateral roll to the hoof of 3.2 degrees and 2.5 degrees during the first half of breakover when trotting, compared with values for no trim-no shoe and trim-standard shoe, respectively. This effect dissipated during the second half of breakover. When horses walked, lateral roll during breakover was not significantly enhanced by use of this shoe. CONCLUSIONS AND CLINICAL RELEVANCE: A shoe with an axial-contoured lateral branch induced greater lateral roll during breakover in trotting horses, but change in orientation of the hoof was small and limited to the first half of breakover.

Computer-assisted kinematic evaluation of induced compensatory movements resembling lameness in horses trotting on a treadmill.

OBJECTIVE: To characterize compensatory movements of the head and pelvis that resemble lameness in horses. ANIMALS: 17 adult horses. PROCEDURE: Kinematic evaluations were performed while horses trotted on a treadmill before and after shoe-induced lameness. Lameness was quantified and the affected limb determined by algorithms that measured asymmetry in vertical movement of the head and pelvis. Induced primary lameness and compensatory movements resembling lameness were assessed by the Friedman test. Association between induced lameness and compensatory movements was examined by regression analysis. RESULTS: Compensatory movements resembling lameness in the ipsilateral forelimb were seen with induced lameness of a hind limb. There was less downward and less upward head movement during and after the stance phase of the ipsilateral forelimb. Doubling the severity of lameness in the hind limb increased severity of the compensatory movements in the ipsilateral forelimb by 50%. Compensatory movements resembling lameness of the hind limb were seen after induced lameness in a forelimb. There was less upward movement of the pelvis after the stance phase of the contralateral hind limb and, to a lesser extent, less downward movement of the pelvis during the stance phase of the ipsilateral hind limb. Doubling the severity of lameness in the forelimb increased compensatory movements of the contralateral hind limb by 5%. CONCLUSIONS AND CLINICAL RELEVANCE: Induced lameness in a hind limb causes prominent compensatory movements resembling lameness in the ipsilateral forelimb. Induced lameness in a forelimb causes slight compensatory movements resembling lameness in the ipsilateral and contralateral hind limbs.

Prevalence and risk factors associated with outcome of surgical removal of pedunculated lipomas in horses: 102 cases (1987-2002).

OBJECTIVE: To determine the prevalence of pedunculated lipomas and identify risk factors affecting postoperative complications and survival in horses at a veterinary teaching hospital undergoing surgery for colic caused by pedunculated lipomas. DESIGN: Retrospective study. ANIMALS: 102 horses with a diagnosis of pedunculated lipoma. PROCEDURE: Age, breed, weight, and sex of horses with pedunculated lipomas were compared with the total equine hospital population and the population of horses admitted for abdominal surgery during the same period. Follow-up information was obtained by reevaluation or contact with owners via telephone or written request. RESULTS: Prevalence of pedunculated lipomas as a reason for abdominal surgery in horses, compared with the population of horses with and without lipomas admitted for abdominal surgery, was 10%. Castrated male Saddlebred and Arabian horses > 14 years old were identified as being at risk for developing pedunculated lipomas. Postoperative complications were detected in 72% of horses with pedunculated lipomas. Variables associated with low survival rates included surgery before 1992, heart rate > 80 beats/min, abnormal color of abdominal fluid, pale mucous membranes, surgery requiring intestinal resection, and inability to attain a mean arterial pressure > or = 100 mm Hg. Horses undergoing surgery from 1992 to 1996, weighing < 409 kg (900 lb), or requiring jejunojejunal anastomosis had a high survival rate. CONCLUSIONS AND CLINICAL RELEVANCE: Although many of the variables reflected the health of the horse at the time of surgery, results may help veterinarians recognize risk factors associated with development of pedunculated lipomas and better predict the outcome of horses undergoing surgery for colic caused by pedunculated lipomas.

Objective determination of pelvic movement during hind limb lameness by use of a signal decomposition method and pelvic height differences.

OBJECTIVE: To evaluate pelvic movement over a large number of strides in sound horses and in horses with induced hind limb lameness by applying methods to the pelvis that have been described for evaluating vertical head movement in horses with induced forelimb lameness. ANIMALS: 17 adult horses. PROCEDURE: Horses were filmed while trotting on a treadmill before and after induction of transient mild and moderate hind limb lamenesses. Vertical pelvic movement was measured by a signal decomposition method. The vertical pelvic signal was decomposed into a periodic component (A1) that occurred at half the stride frequency (representing vertical pelvic movement caused by lameness) and another periodic component (A2) that occurred at stride frequency (representing normal vertical pelvic movement of a trotting horse). Vertical pelvic and foot positions were correlated for each stride to compare the difference between the minimum and maximum heights of the pelvis during and after stance of the right hind limb to the minimum and maximum heights of the pelvis during and after stance of the left hind limb. RESULTS: Maximum pelvic height difference and lameness amplitude (A1) differed significantly between sound and mild or moderate hind limb lameness conditions. Mean A1 value for vertical pelvic movement in sound horses was less than that previously reported for vertical head movement. CONCLUSION AND CLINICAL RELEVANCE: Pelvic height differences and signal decomposition of pelvic movement can be used to objectively evaluate hind limb lameness in horses over a large number of strides in clinical and research settings.

Evaluation of a sensor-based system of motion analysis for detection and quantification of forelimb and hind limb lameness in horses.

OBJECTIVE: To compare a sensor-based accelerometer-gyroscopic (A-G) system with a video-based motion analysis system (VMAS) technique for detection and quantification of lameness in horses. ANIMALS: 8 adult horses. PROCEDURE: 2 horses were evaluated once, 2 had navicular disease and were evaluated before and after nerve blocks, and 4 had 2 levels of shoe-induced lameness, alternatively, in each of 4 limbs. Horses were instrumented with an accelerometer transducer on the head and pelvis, a gyroscopic transducer on the right forelimb and hind feet, and a receiver-transmitter. Signals from the A-G system were collected simultaneously with those from the VMAS for collection of head, pelvis, and right feet positions with horses trotting on a treadmill. Lameness was detected with an algorithm that quantified lameness as asymmetry of head and pelvic movements. Comparisons between the A-G and VMAS systems were made by use of correlation and agreement (kappa value) analyses. RESULTS: Correlation between the A-G and VMAS systems for quantification of lameness was linear and high (r2 = 0.9544 and 0.8235 for forelimb and hind limb, respectively). Quantification of hind limb lameness with the A-G system was higher than measured via VMAS. Agreement between the 2 methods for detection of lameness was excellent (kappa = 0.76) for the forelimb and good (kappa = 0.56) for the hind limb. CONCLUSIONS AND CLINICAL RELEVANCE: The A-G system detected and quantified forelimb and hind limb lameness in horses trotting on the treadmill. Because the data are collected wirelessly, this system might be used to objectively evaluate lameness in the field.