OBJECTIVE To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. ANIMALS 5 nonlame adult light-breed horses. PROCEDURES Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile–low surface area calks, with low profile–high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments. RESULTS Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile–high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.

OBJECTIVE To compare the effects of 3 walkway cover types on temporospatial and ground reaction force measurements of dogs during gait analysis with a pressure-sensitive walkway (PSW). ANIMALS 35 client- and staff-owned dogs (25 nonlame and 10 lame). PROCEDURES In a crossover study design, all dogs were evaluated at a comfortable walk on a PSW to which 3 cover types (a 0.32-cm-thick corrugated vinyl mat or a 0.32- or 0.64-cm-thick polyvinyl chloride yoga mat) were applied in random order. Temporospatial and ground reaction force measurements were obtained and compared among cover types within the nonlame and lame dog groups. RESULTS Several variables, including maximum peak pressure, maximum force (absolute and normalized as a percentage of body weight), and vertical impulse (absolute and normalized) differed significantly in most comparisons among cover types for both nonlame and lame dogs. There was no significant difference in maximum force values between the 0.32-cm-thick corrugated vinyl and 0.64-cm-thick polyvinyl chloride cover types for both nonlame and lame dogs. CONCLUSIONS AND CLINICAL RELEVANCE To the authors’ knowledge, the cover type used during data collection with a PSW is rarely provided in published reports on this topic. The findings in this study suggested that to ensure that PSW data for dogs are collected in a standardized manner, the same cover type should be used during follow-up visits to evaluate clinical outcomes, for the duration of research studies, and at all locations for multi-institutional studies. The cover type should be specified in future PSW studies to allow direct comparisons of findings between studies.

OBJECTIVE To develop contact time (ConT) and withers height-normalized relative ConT (ConT*) for force platform gait analysis of dogs. ANIMALS 29 healthy client-owned dogs. PROCEDURES Height at the most dorsal aspect of the shoulders (withers) was measured with a framing square. Dogs were trotted across a force platform at their preferred velocity with controlled acceleration (± 0.5 m/s2). Ranges of ConT and ConT* centered on the population mean ConT were created. Variance effects on ground reaction forces (GRFs) for 4 thoracic limb and 4 pelvic limb ConT and associated ConT* ranges were examined. Efficiency of trial capture and effects of velocity ranges on GRF variance were determined. RESULTS Individual dogs had the greatest effect on GRF variance for thoracic and pelvic limbs. Narrow ConT and ConT* ranges had few significant effects on GRFs but were inefficient at capturing trials. The ConT ranges of 0.22 to 0.29 seconds and 0.19 to 0.25 seconds for thoracic and pelvic limbs, respectively, provided the most efficient rates of trial capture with the fewest significant effects on GRFs. Compared with ConT and ConT* ranges, relative velocity ranges had higher efficiency and smaller GRF variance effects. CONCLUSIONS AND CLINICAL RELEVANCE Dogs of various morphologies have differing limb velocities. Use of ConT as a surrogate for limb velocity may improve GRF data quality. We identified ConT and ConT* ranges associated with low GRF variance. However, relative velocity ranges captured data more efficiently. Efficient capture of data may help avoid worsening of lameness during gait analysis of dogs.

OBJECTIVE To determine whether addition of epinephrine to a lidocaine solution would prolong and potentiate the efficacy of a palmar digital nerve block (PDNB) in horses. ANIMALS 6 adult horses with naturally occurring forefoot lameness. PROCEDURES Initially, a PDNB with a 2% lidocaine solution was performed on the affected foot of each horse. Three days later, the PDNB was repeated with a 1% lidocaine solution or a 1% lidocaine solution containing epinephrine (dilution, 1:200,000). After another 3-day washout period, the PDNB was repeated with the treatment opposite that administered for the second PDNB. Gait was analyzed with a computerized lameness analysis system and heart rate and extent of skin sensation between the heel bulbs of the blocked foot were evaluated at predetermined times for 2 hours after each PDNB. RESULTS Efficacy and duration of the PDNB did not differ significantly between the 2% and 1% lidocaine treatments. The addition of epinephrine to the 1% lidocaine solution improved the efficacy and prolonged the duration of the PDNB. It also resulted in a positive correlation between skin desensitization and amelioration of lameness. Median heart rate remained unchanged throughout the observation period for all 3 treatments. No adverse effects associated with the PDNBs were observed. CONCLUSIONS AND CLINICAL RELEVANCE Addition of epinephrine (dilution, 1:200,000) to a 1% lidocaine solution improved the efficacy and prolonged the duration of a PDNB in horses with naturally occurring lameness and might be clinically useful for lameness evaluations and standing surgery of the forefoot of horses.

OBJECTIVE To assess effects of speed on kinematic variables measured by use of extremity-mounted inertial measurement units (IMUs) in nonlame horses performing controlled exercise on a treadmill. ANIMALS 10 nonlame horses. PROCEDURES 6 IMUs were attached at predetermined locations on 10 nonlame Franches Montagnes horses. Data were collected in triplicate during trotting at 3.33 and 3.88 m/s on a high-speed treadmill. Thirty-three selected kinematic variables were analyzed. Repeated-measures ANOVA was used to assess the effect of speed. RESULTS Significant differences between the 2 speeds were detected for most temporal (11/14) and spatial (12/19) variables. The observed spatial and temporal changes would translate into a gait for the higher speed characterized by increased stride length, protraction and retraction, flexion and extension, mediolateral movement of the tibia, and symmetry, but with similar temporal variables and a reduction in stride duration. However, even though the tibia coronal range of motion was significantly different between speeds, the high degree of variability raised concerns about whether these changes were clinically relevant. For some variables, the lower trotting speed apparently was associated with more variability than was the higher trotting speed. CONCLUSIONS AND CLINICAL RELEVANCE At a higher trotting speed, horses moved in the same manner (eg, the temporal events investigated occurred at the same relative time within the stride). However, from a spatial perspective, horses moved with greater action of the segments evaluated. The detected changes in kinematic variables indicated that trotting speed should be controlled or kept constant during gait evaluation.

OBJECTIVE To characterize a population of Brazilian minipigs with naturally occurring syndactyly by use of plain radiographs and CT images and to evaluate kinetic and temporospatial variables by use of a pressure-sensing walkway. ANIMALS 10 Brazilian minipigs from 6 to 8 months of age (group 1, 5 healthy pigs [body weight, 10.5 to 18.5 kg]; group 2, 5 pigs with syndactyly [body weight, 7.5 to 18.0 kg]). PROCEDURES Forelimbs and hind limbs of all pigs were assessed by use of radiography and CT. Gait was analyzed by use of a pressure-sensing walkway. RESULTS All limbs of all pigs of group 2 had syndactyly. Two forelimbs had complex-1 syndactyly, and 8 forelimbs had complex-2 syndactyly. Four hind limbs had simple syndactyly, 1 hind limb had complex-1 syndactyly, and 5 hind limbs had complex-2 syndactyly. Kinetic and temporospatial values and symmetry indices did not differ between groups. Plantar and palmar surfaces of healthy pigs had 2 areas of maximum pressure, whereas plantar and palmar surfaces of pigs with syndactyly had only 1 area of maximum pressure. CONCLUSIONS AND CLINICAL RELEVANCE In this population of pigs, the most common type of syndactyly was complex-2, and comparison with the healthy group revealed no alteration in kinetic and temporospatial variables. Therefore, results suggested that syndactyly in young minipigs did not cause locomotor disturbances.

OBJECTIVE To evaluate the effects of selective hip joint denervation on gait abnormalities and signs of hip joint pain in dogs. ANIMALS 6 healthy adult hound-type dogs. PROCEDURES Minimally invasive denervation was performed on the right hip joint of each dog. Two weeks later, sodium urate was injected into the right hip joint to induce synovitis. Dogs were evaluated clinically and by use of instrumented gait analysis before and 2 weeks after minimally invasive denervation and 4, 8, and 24 hours after induction of synovitis. Dogs were euthanized, and necropsy and histologic examination were performed. RESULTS No kinetic or kinematic gait modifications were detected 2 weeks after minimally invasive denervation. Denervation did not eliminate signs of pain and lameness associated with sodium urate–induced synovitis. Results of histologic examination confirmed that denervation was an effective method for transecting the innervation of the craniolateral and caudolateral aspects of the hip joint capsule. CONCLUSIONS AND CLINICAL RELEVANCE In this study, minimally invasive denervation did not result in gait modifications in dogs. Denervation did not abolish the signs of pain and lameness associated with generalized induced synovitis of the hip joint. Further studies are required before conclusions can be drawn regarding the clinical usefulness of hip joint denervation for dogs with hip dysplasia.

OBJECTIVE To develop a model of hip joint synovitis on the basis of intra-articular injection of a sodium urate suspension in dogs and to characterize associated gait changes. ANIMALS 6 healthy adult dogs. PROCEDURES Each dog was sedated, and synovitis was induced by injection of 1 mL of a sodium urate suspension (20 mg/mL) into the right hip joint under ultrasonographic guidance. Observational and instrumented gait analyses to determine temporospatial, kinetic, and kinematic variables were performed prior to and 4, 8, and 24 hours after sedation and synovitis induction. RESULTS Injection of a sodium urate suspension into the hip joint of healthy dogs resulted in lameness of the ipsilateral pelvic limb as determined by observational and instrumented gait analyses. For all dogs, lameness was clinically detectable within 1.5 to 2 hours after injection, reached its maximum intensity at 4 hours after injection, and had subsided by 24 hours after injection. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that injection of a sodium urate suspension into the hip joint of healthy dogs reliably induced synovitis and signs of pain and lameness in the ipsilateral pelvic limb that lasted 24 hours. This model can be used in conjunction with instrumented gait analysis to provide information on gait changes associated with hip joint disease and might be useful for evaluating the efficacy of analgesics or other interventions for the treatment of hip joint disease in dogs.

OBJECTIVE To characterize and compare gait variables in Doberman Pinschers with and without cervical spondylomyelopathy (CSM). ANIMALS 18 Doberman Pinschers (9 clinically normal dogs and 9 CSM-affected dogs). PROCEDURES A neurologic examination was performed on all dogs. The diagnosis of CSM was confirmed with MRI. Temporospatial and kinetic gait variables were measured by use of a pressure-sensitive walkway. Temporospatial variables evaluated included stance phase duration, swing phase duration, gait cycle duration, stride length, and gait velocity. Kinetic variables evaluated included peak vertical force and vertical impulse. Random-effects linear regression was used to determine the difference between CSM-affected and clinically normal dogs for each of the 7 variables. RESULTS Values for temporospatial variables were significantly smaller in the thoracic limbs of CSM-affected dogs, compared with values for the thoracic limbs of clinically normal dogs. For the kinetic variables, peak vertical force was significantly higher in the thoracic limbs than the pelvic limbs for all dogs. Vertical impulse values were higher in the thoracic limbs than the pelvic limbs. There were significant differences in mean vertical impulse between the thoracic and pelvic limbs for both groups. CONCLUSIONS AND CLINICAL RELEVANCE In this study, significant differences in temporospatial variables were identified between the thoracic limbs of clinically normal and CSM-affected dogs, with the values being smaller for the CSM-affected dogs than for the clinically normal dogs. A pressure-sensitive walkway may provide a valid, practical option for rapid, objective assessment of gait and response to treatment in dogs with CSM.

Objective- To compare accuracy of a noninvasive single-plane fluoroscopic analysis technique with radiostereometric analysis (RSA) for determining 3-D femorotibial poses in a canine cadaver stifle joint treated by tibial-plateau-leveling osteotomy (TPLO). Sample- Left pelvic limb from a 25-kg adult mixed-breed dog. Procedures- A CT scan of the left pelvic limb was performed. The left cranial cruciate ligament was transected, and a TPLO was performed. Radiopaque beads were implanted into the left femur and tibia, and the CT scan was repeated. Orthogonal fluoroscopic images of the left stifle joint were acquired at 5 stifle joint flexion angles ranging from 110° to 150° to simulate a gait cycle; 5 gait cycles were completed. Joint poses were calculated from the biplanar images by use of a digitally modified RSA and were compared with measurements obtained by use of hybrid implant-bone models matched to lateral-view fluoroscopic images. Single-plane measurements were performed by 2 observers and repeated 3 times by the primary observer. Results- Mean absolute differences between results of the single-plane fluoroscopic analysis and modified RSA were 0.34, 1.05, and 0.48 mm for craniocaudal, proximodistal, and mediolateral translations, respectively, and 0.56°, 0.85°, and 1.08° for flexion-extension, abduction-adduction, and internal-external rotations, respectively. Intraobserver and interobserver mean SDs did not exceed 0.59 mm for all translations and 0.93° for all rotations. Conclusions and Clinical Relevance- Results suggested that single-plane fluoroscopic analysis by use of hybrid implant-bone models may be a valid, noninvasive technique for accurately measuring 3-D femorotibial poses in dogs treated with TPLO.