Objective—To ascertain the effectiveness of evaluating
ground reaction forces (GRFs) at velocities during
walking and trotting in dogs with naturally occurring
lameness and determine whether walking would provide
sufficient motion to adequately characterize
GRFs with respect to trotting.
Animals—29 dogs with a naturally occurring tear of
the cranial cruciate ligament.
Procedure—Dogs were walked and trotted over a
force platform, and GRFs were recorded during the
stance phase. Correlation was used to assess the
agreement between walking and trotting for GRF. The
coefficient of variation was calculated to assess the
relative variation of outcome variables among the
gaits. Group means for walking GRF were compared
between dogs that trotted and that failed to trot.
Results—GRFs during walking and trotting were
highly correlated. The coefficient of variation was
smaller for GRFs during walking than during trotting.
Dogs that failed to trot had significantly smaller mean
values of peak vertical force and vertical impulse during
walking, compared with values for dogs that were
able to trot.
Conclusions and Clinical Relevance—Either velocity
is acceptable for GRF evaluation in dogs. Mean
GRF during walking was significantly different
between dogs that could and could not trot, principally
because dogs with the most severe lameness
failed to trot. These dogs would be eliminated from a
clinical study, and thus, that study would become
biased toward dogs that were less lame. In that situation,
differences between interventions may be less
pronounced, because they would be evaluated on
dogs with less lameness. (Am J Vet Res 2003;64:
Animals—58 dogs with lameness secondary to osteoarthritis.
Procedures—Dogs enrolled in the placebo arm of an FDA-approved study were evaluated to determine the relationship between subjective (caregiver responses) and objective (force platform gait analysis) patient outcome measures.
Results—A caregiver placebo effect for owners evaluating their dog's lameness occurred 39.7% of the time. A caregiver placebo effect occurred 44.8% of the time when veterinarians examined dogs for lameness at a walk, 44.8% of the time when veterinarians examined dogs for lameness at a trot, and 43.1% of the time when veterinarians evaluated dogs for signs of pain on palpation of the joint. This effect was significantly enhanced with time. Mean ground reaction forces (GRFs) remained unchanged for dogs during treatment with the placebo. Individually, of 58 dogs, 5 had GRFs that worsened by ≥ 5% over 42 days, 7 had GRFs that improved by ≥ 5% over 42 days, and 46 had GRFs that remained unchanged.
Conclusions and Clinical Relevance—A caregiver placebo effect was common in the evaluation of patient response to treatment for osteoarthritis by both pet owners and veterinarians. Force platform gait analysis was an unbiased outcome measure for dogs with lameness from osteoarthritis. A caregiver placebo effect should be considered when interpreting owner and veterinary reports of patient response to treatment.
Objective—To investigate factors influencing screw loosening after triple pelvic osteotomy (TPO) and ischial wire stabilization of the acetabular segment.
Design—Retrospective case series.
Animals—227 dogs with congenital hip dysplasia or subluxated hip joints.
Procedures—Medical records and radiographs of 227 dogs that underwent 332 TPO procedures were evaluated, and data pertaining to screw type, plate position, sacral screw engagement, use of ischial interfragmentary wires, and pelvic alignment were assessed for associations with screw loosening.
Results—Complications developed in 96 of the 332 (29%) procedures. Cancellous screws without sacral engagement were associated with the lowest frequency (6%) of loosening, compared with cancellous and cortical screws engaging the sacrum and cortical screws that did not engage the sacrum. Frequency of screw loosening increased when cortical or cancellous screws engaged the sacrum and when cortical screws were used. In dogs that had surgery bilaterally, the first limb on which TPO was performed had a higher frequency of screw loosening than the second limb. Pelvic alignment loss was greatest (5.4°) when the 3 most cranial screws were loosened. Loss of pelvic alignment was significantly different between dogs that underwent surgery and had complications and those that underwent surgery and did not have complications in association with loosening of 1, 2, and 3 screws.
Conclusions and Clinical Relevance—TPO screw loosening was multifactorial and related to stability of the affected ilium, screw type, and screw position. Placing cancellous screws that do not engage the sacrum in pelvic osteotomy plate positions 1 through 3 may decrease the number of screws that loosen.
Objective—To evaluate the effect of focused extracorporeal shock wave therapy (ESWT) and radial pressure wave therapy (RPWT) on immunohistochemical staining for substance P and calcitonin gene-related peptide (CGRP) in the skin and periosteum of sheep.
Procedures—All 4 limbs of 36 sheep were treated with ESWT, RPWT, or a sham treatment. For 14 days after treatment, at least 2 sheep were euthanized daily and tissue was harvested for histologic evaluation of nerves via staining for substance P and CGRP in the skin and periosteum.
Results—No effects of ESWT or RPWT were observed on the number of nerves with stain uptake for substance P or CGRP in the skin or periosteum.
Conclusions and Clinical Relevance—Substance P- and CGRP-containing nerve fibers are not disrupted by EWST or RPWT. Further studies are needed to identify the mechanism of analgesia observed in association with these treatment modalities.
Objective—To identify the duration and potential
mechanisms of analgesia following extracorporeal
shock wave therapy (ESWT) and radial pressure wave
therapy (RPWT) in limbs of horses and sheep.
Animals—6 horses and 30 sheep.
Procedure—An electrical stimulus was used to identify
the nociceptive threshold for each horse daily for
3 days before treatment (baseline) with ESWT or
RPWT, 8 hours after treatment, and at 24-hour intervals
for 7 days after treatment. Testing was conducted
for the treatment field (midmetacarpus or
midmetatarsus) and nerve field (medial and lateral
forelimb heel bulbs) distal to a treatment site that
included the nerve on the abaxial surface of the proximal
sesamoid bone. All 4 limbs of 30 sheep were
treated with ESWT, RPWT, or a sham treatment. Two
sheep were euthanatized daily and tissue harvested
for histologic evaluation of nerves, and concentrations
of substance P and calcitonin gene-related peptide
were measured in the skin and periosteum.
Results—Values did not differ significantly between
baseline and after treatment for the treatment field or
nerve field sensation. There was a large difference in
the slope when data for horses were plotted for the
first 3 days after treatment, compared with the slope
for days 4 to 7 after treatment. No differences were
found in neuropeptide concentrations after treatment
of the sheep, but there was an inflammatory
response in the treated nerves.
Conclusions and Clinical Relevance—A small cutaneous
analgesic effect may exist at the treatment site
for approximately 3 days after ESWT or RPWT in
horses. (Am J Vet Res 2005;66:1702–1708)
Objective—To document peak vertical force (PVF)
and vertical impulse (VI) in the pads of Greyhounds
and Labrador Retrievers.
Animals—8 Greyhounds and 8 Labrador Retrievers.
Procedure—Velocity and acceleration were restricted
to ranges of 0.9 to 1.1 m/s and –0.1 to 0.1 m/s2,
respectively. The PVF and VI measurements were collected
from digital pad (DP)-2, -3, -4, and -5 and the
metacarpal pad (McP) or metatarsal pad (MtP) of each
limb in each dog.
Results—We found no significant differences
between the left and right forelimbs or hind limbs for
any pad in either breed. Vertical forces in the forelimb
were always greater than those in the hind limb. The
PVF in the forelimbs of Greyhounds was greatest in
DP-3, -4, and -5 and DP-3, DP-4, and the MtP in the
hind limbs. The VI in Greyhound forelimbs was greatest
in DP-3, -4, and -5 but greatest in DP-4 in the hind
limbs. The PVF in the forelimbs of Labrador Retrievers
was greatest in the McP, whereas in the hind limbs it
was greatest in DP-4. The VI in Labrador Retriever
forelimbs was greatest in DP-3, DP-4, and the McP
but greatest in DP-3 and -4 in the hind limbs.
Significant differences were detected in load distribution
between the breeds.
Conclusions and Clinical Relevance—This study
confirms that DP-3 and DP-4 are major weight-bearing
pads in dogs. However, loads were fairly evenly distributed,
and DP-5 and the McP or MtP bear a substantial
amount of load in both breeds. (Am J Vet Res 2004;65:1497–1501)
Objective—To determine the relationship between serum cortisol concentration and pain severity as measured by force platform gait analysis in dogs with experimentally induced synovitis of the stifle joint.
Animals—10 healthy hound-type dogs.
Procedures—Dogs underwent 2 study phases. In the first phase, serum cortisol concentration, systolic arterial blood pressure, heart rate, and gait data were obtained at 0 (first sample), 2.5, 5, 7.5, and 10 hours. In the second phase, the same data were gathered immediately before (0 hours) and 2.5, 5, 7.5, and 10 hours after induction of acute urate synovitis in the left stifle joint. Data were statistically evaluated to compare changes in variable values over time and to determine the accuracy of serum cortisol measurements for diagnosis of acute orthopedic pain.
Results—Following induction of synovitis, ground reaction forces were significantly decreased relative to preinduction values at 2.5, 5.0, 7.5, and 10.0 hours and serum cortisol concentration was significantly increased at 2.5 hours. A cortisol concentration of ≥ 1.6 μg/dL indicated pain with a 91% sensitivity and 35% specificity.
Conclusions and Clinical Relevance—In this model, cortisol concentration may be useful for diagnosing pain in dogs. Although, with a cutoff of ≥ 1.6 μg/dL, pain would be detected in most dogs with pain, some pain-free dogs would also be identified as having pain. Conversely, dogs with a serum cortisol of < 1.6 μg/dL would be unlikely to have pain. Validation of this diagnostic test in a large, heterogeneous group of clinical patients is necessary.
Objective—To determine short- and long-term rates of successful outcomes of surgical and nonsurgical treatments for overweight dogs with cranial cruciate ligament rupture (CCLR).
Design—Prospective, randomized, clinical trial.
Animals—40 client-owned overweight dogs with unilateral CCLR.
Procedures—Dogs were randomly assigned to nonsurgical (physical therapy, weight loss, and NSAID administration) or surgical (tibial plateau leveling osteotomy) treatment groups; dogs in both groups received the same nonsurgical treatments. Dogs were evaluated immediately before and 6, 12, 24, and 52 weeks after initiation of treatments via owner questionnaires, gait analysis, and dual-energy x-ray absorptiometry. A successful outcome was defined as an affected limb net ground reaction force > 85% of the value for healthy dogs and a ≥ 10% improvement in values of questionnaire variables.
Results—Owner questionnaire responses indicated dogs in both groups improved during the study, but dogs in the surgical treatment group seemed to have greater improvement. Body fat percentages for dogs in both treatment groups significantly decreased during the study. Surgical treatment group dogs had significantly higher peak vertical force for affected limbs versus nonsurgical treatment group dogs at the 24- and 52-week evaluation times. Surgical treatment group dogs had a higher probability of a successful outcome (67.7%, 92.6%, and 75.0% for 12-, 24-, and 52-week evaluations, respectively) versus nonsurgical treatment group dogs (47.1%, 33.3%, and 63.6% for 12-, 24-, and 52-week evaluations, respectively).
Conclusions and Clinical Relevance—Overweight dogs with CCLR treated via surgical and nonsurgical methods had better outcomes than dogs treated via nonsurgical methods alone. However, almost two-thirds of the dogs in the nonsurgical treatment group had a successful outcome at the 52-week evaluation time.
Objective—To evaluate the effects of perioperative oral administration of tramadol, firocoxib, and a tramadol-firocoxib combination on signs of pain and limb function after tibial plateau leveling osteotomy in dogs.
Animals—30 adult client-owned dogs with unilateral cranial cruciate ligament disease.
Procedures—Dogs were allocated into 3 treatment groups (tramadol, firocoxib, and a tramadol-firocoxib combination). Signs of pain (short-form Glasgow composite measure pain scale), serum cortisol concentrations, and limb function (pressure platform gait analysis) were recorded at several time points before surgery and through 3 days after surgery. Outcome measures were compared among groups.
Results—A significantly greater number of dogs in the tramadol group (8/10 dogs) had a pain score > 6 after surgery, compared with the other groups. No significant differences were detected in the pain scores between the firocoxib and the tramadol-firocoxib combination groups. There were no significant differences in serum cortisol concentrations among the 3 groups. Limb function was significantly decreased for dogs in the tramadol group on days 1 and 2 after surgery and in the firocoxib group on day 1 after surgery. Although limb function decreased for dogs in the tramadol-firocoxib combination group, the change was not significant for any day after surgery.
Conclusions and Clinical Relevance—Dogs that received firocoxib orally, alone or in combination with tramadol, had lower pain scores, lower rescue opiate administration, and greater limb function than dogs that received only tramadol. When used alone, oral administration of tramadol may not provide sufficient analgesic efficacy to treat dogs with pain after orthopedic surgical procedures.
Objective—To measure alterations in lameness severity that occur following use of extracorporeal shock wave therapy (ESWT) in horses with naturally occurring unilateral forelimb lameness.
Design—Nonrandomized clinical trial.
Animals—9 horses with unilateral forelimb lameness.
Procedures—Force platform gait analysis was performed prior to administration of any treatments (baseline) and after use of local anesthesia to eliminate the lameness. Extracorporeal shock wave therapy was then administered, and gait analysis was repeated 8 hours later and then daily for 7 days.
Results—Compared with the baseline value, peak vertical force was significantly increased 8 hours and 2 days after ESWT, and peak vertical force on day 2 was not significantly different from force measured after use of local anesthesia to eliminate the lameness. Similarly, vertical impulse was significantly increased, compared with the baseline value, 8 hours and 2 days after ESWT, but at all times, it was significantly lower than vertical impulse measured after use of local anesthesia.
Conclusions and Clinical Relevance—Results suggest that in horses with naturally occurring lameness, use of ESWT results in a period of acute improvement in lameness severity that typically persists for 2 days. Thus, in horses undergoing ESWT, exercise should be controlled for a minimum of 2 days after treatment to prevent further injury.