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:
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 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.