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
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.
Conclusions 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. (Am J Vet Res 2004;65:
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 (κ 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 (κ = 0.76) for the
forelimb and good (κ = 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.
( Am J Vet Res 2004;65:665–670)
Objective—To investigate continuous wavelet transformation
and neural network classification of gait
data for detecting forelimb lameness in horses.
Animals—12 adult horses with mild forelimb lameness.
Procedure—Position of the head and right forelimb
foot, metacarpophalangeal (ie, fetlock), carpal, and
elbow joints was determined by use of kinematic
analysis before and after palmar digital nerve blocks.
We obtained 8 recordings from horses without lameness,
8 with right forelimb lameness, and 8 with left
forelimb lameness. Vertical and horizontal position of
the head and vertical position of the foot, fetlock,
carpal, and elbow joints were processed by continuous
wavelet transformation. Feature vectors were
created from the transformed signals and a neural
network trained with data from 6 horses, which was
then tested on the remaining 2 horses for each category
until each horse was used twice for training and
testing. Correct classification percentage (CCP) was
calculated for each combination of gait signals tested.
Results—Wavelet-transformed vertical position of
the head and right forelimb foot had greater CCP
(85%) than untransformed data (21%). Adding data
from the fetlock, carpal, or elbow joints did not
improve CCP over that for the head and foot alone.
Conclusions and Clinical Relevance—Wavelet
transformation of gait data extracts information that is
important for the detection and differentiation of forelimb
lameness of horses. All of the necessary information
to detect lameness and differentiate the side
of lameness can be obtained by observation of vertical
head movement in concert with movement of the
foot of 1 forelimb. (Am J Vet Res 2003;64:1376–1381)
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.
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.
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.
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.
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° and 2.5° 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. (Am J Vet Res
Objective—To characterize compensatory movements
of the head and pelvis that resemble lameness
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. (Am J Vet Res 2005;66:646–655)
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.