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in Journal of the American Veterinary Medical Association

SUMMARY

The percentage of limb contact time spent in braking and propulsion was determined for the forelimbs and hind limbs of Greyhounds at 2 walk speeds and 3 trot speeds. Limb contact times decreased significantly (P < 0.05) as velocity increased between each velocity range. At a slow walk (0.92 to 1.03 m/s), braking and propulsion were 56.1 and 43.6% of contact time in the forelimbs and 41.6 and 58.1% of contact time in the hind limbs, respectively. At a fast walk (1.06 to 1.17 m/s), braking and propulsion were 56.7 and 43.5% of contact time in the forelimbs and 41.5 and 58.4% of contact time in the hind limbs, respectively. There was no significant difference in the percentage of contact time that the forelimbs and hind limbs spent in braking and propulsion between the 2 walk velocities. At the slow trot (1.5 to 1.8 m/s), braking and propulsion were 56.8 and 43% of contact time in the forelimbs and 30.1 and 67.6% of contact time in the hind limbs, respectively. At the medium trot (2.1 to 2.4 m/s), braking and propulsion were 55.9 and 43.5% of contact time in the forelimbs and 33.8 and 63.2% of contact time in the hind limbs, respectively. At the fast trot (2.7 to 3.0 m/s), braking and propulsion were 57.2 and 43% of contact time in the forelimbs and 37.5 and 61.1% of contact time in the hind limbs, respectively. Braking percentage increased and propulsive percentage decreased significantly (P < 0.05) in the hind limbs between the slow and fast trot speeds. There was no significant difference in the percentage of forelimb contact time spent in braking and propulsion between the walk and the trot gaits or among the 3 trot velocities.

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine plasma tramadol concentrations in cats following a single dose of oral and transdermal formulations and the pharmacokinetics for and the concentration of tramadol in the transdermal formulation.

ANIMALS

8 healthy client-owned domestic shorthair cats.

PROCEDURES

1 cat was orally administered 1 dose of tramadol (2 mg/kg), and 7 cats received 1 dose of a proprietary compounded tramadol gel product (median actual dose, 2.8 mg/kg) applied to their inner pinnae. Plasma tramadol concentrations were measured with high-performance liquid chromatography–mass spectrometry at fixed times over 24 hours.

RESULTS

Plasma tramadol concentrations were undetectable or much lower (range, < 1 to 4.3 ng/mL) following application of the transdermal formulation, compared with those following oral administration (maximum plasma tramadol concentration, 261.3 ng/mL [at 4 hours]). Tramadol pharmacokinetics for the transdermal formulation could not be determined. Tramadol concentrations of the transdermal gel product exceeded the estimated label dose in all analyzed gel samples, with concentrations greater than the 90% to 110% United States Pharmacopeia standard for compounded drugs.

CONCLUSIONS AND CLINICAL RELEVANCE

Application of 1 dose of the proprietary transdermal formulation did not yield clinically relevant plasma tramadol concentrations in cats. Although this proprietary formulation is currently available to prescribing veterinarians, it should be used with caution.

Full access
in American Journal of Veterinary Research

Summary

Force plate gait analysis was used to study the effects of subject stance time and velocity on ground reaction forces in 6 adult Greyhounds at the trot. Data for 210 valid trials were obtained. Stance time negatively correlated with velocity (r = −0.85 for the forelimbs, r = −0.61 for the hind limbs), decreasing as velocity increased. Stance time in the forelimbs and hind limbs correlated more closely with changes in vertical peak force and impulse than did velocity. The trials were divided into 3 distinct velocity ranges (V1 = 1.5 to 1.8 m/s, V2 = 2.1 to 2.4 m/s, and V3 = 2.7 to 3.0 m/s), 3 distinct forelimb stance time ranges (fst1 = 0.144 to 0.176 second, fst2 = 0.185 to 0.217 second, and fst3 = 0.225 to 0.258 second), and 3 distinct hind limb stance time ranges (hst1 = 0.105 to 0.132 second, hst2 = 0.139 to 0.165 second, and hst3 = 0.172 to 0.198 second). Peak forces increased as velocity increased and decreased as stance time increased. Vertical impulse decreased as velocity increased and increased as stance time increased. The relation between stance time, subject velocity, and ground reaction forces was documented for clinically normal Greyhounds at the trot. Changes in stance time accurately reflected changes in subject velocity and ground reaction forces in clinically normal dogs and could be used to normalize trial data within a sampling period.

Free access
in American Journal of Veterinary Research

Summary

Force plate gait analysis was used to study the effects of subject stance time and velocity on ground reaction forces in 5 adult Greyhounds at the walk. Data from 146 valid trials were obtained. Stance time and velocity were linearly related, and stance time had a strong, negative correlation with velocity (r = −0.72 for the forelimbs, r = −0.56 for the hind limbs). Stance time correlated more closely with changes in peak vertical force and impulse than did velocity. Stance time and velocity correlated less strongly with braking and propulsion forces and impulses. The trials were divided into 2 distinct velocity ranges (V1 = 0.92 to 1.03 m/s, V2 = 1.06 to 1.17 m/s), 2 distinct forelimb stance time ranges (fst1 = 0.43 to 0.48 second, fst2 = 0.50 to 0.55 second), and 2 distinct hind limb stance time ranges (hst1 = 0.40 to 0.45 second, hst2 = 0.46 to 0.51 second). Five trials from each dog were included in each range, and the mean values were used to evaluate changes in ground reaction forces between groups. Peak vertical force in the forelimbs decreased significantly (P = 0.048) as fst increased; however, difference was not detected in vertical force between velocity groups. Peak vertical force in the hind limbs decreased significantly (P = 0.001) as hst increased and increased significantly (P = 0.000) as velocity increased. Differences were not observed between groups in forelimb or hind limb braking and propulsive forces. Vertical impulse in the forelimbs and hind limbs decreased as velocity increased and increased as stance time increased. Braking impulse in the forelimbs decreased as velocity increased and increased as fst increased. Braking force in the hind limbs did not change between velocity or stance time groups. Propulsive impulse in the hind limbs decreased as velocity increased and increased as hst increased. Stance time was a sensitive and accurate indicator of subject velocity in clinically normal dogs at the walk and correlated more closely with changes in some ground reaction forces than did velocity measurements. Stance time measurements could be used to normalize trial data within a sampling period and document consistency in velocity during force plate analysis of clinically normal dogs at the walk.

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To investigate the effects of short-term and prolonged topical instillation of 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, and 0.03% flurbiprofen sodium on corneal sensitivity (CS) in ophthalmologically normal cats.

ANIMALS

12 healthy adult domestic shorthair cats.

PROCEDURES

In the first of 2 study phases, each cat received 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, 0.03% flurbiprofen sodium, and saline (0.9% NaCl; control) solutions (1 drop [0.05 mL]/eye, q 5 min for 5 treatments) in a randomized order with a 2-day washout period between treatments. For each cat, an esthesiometer was used to measure CS before treatment initiation (baseline) and at 15, 30, 45, and 60 minutes after the last dose. There was a 2-day washout period between phases. The second phase was similar to the first, except each treatment was administered at a dosage of 1 drop/eye, twice daily for 5 days and CS was measured before treatment initiation and at 15 minutes and 24 and 48 hours after the last dose. The Friedman test was used to evaluate change in CS over time.

RESULTS

None of the 4 treatments had a significant effect on CS over time in either study phase.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that neither short-term nor prolonged topical instillation of 3 NSAID ophthalmic solutions had any effect on the CS of healthy cats. Given potential differences in cyclooxygenase expression between healthy and diseased eyes, further investigation of the effects of topical NSAID instillation in the eyes of cats with ocular surface inflammation is warranted.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To identify common errors in film and digital radiographs provided by referring veterinarians and determine the effect of such errors on the perceived diagnostic quality of image sets.

Design—Prospective study.

Sample—135 sets of radiographic images acquired by referring veterinarians for client-owned small animals evaluated at a university hospital.

Procedures—Sets of radiographs were prospectively collected and evaluated for proper performance of various radiographic technical variables including exposure, collimation, positioning, inclusion of all appropriate views, presence of artifacts, radiation safety, and labeling. Sets of radiographs were subjectively determined to be of diagnostic or nondiagnostic quality by 2 evaluators.

Results—The variables exposure, correct positioning, absence of artifacts, and acquisition of all appropriate views were significantly associated with a determination of diagnostic quality for radiograph sets. Correct patient labeling, radiation safety, and x-ray beam centering and collimation were not associated with a determination of diagnostic quality for radiograph sets. The number of categories with errors was significantly associated with identification of radiograph sets as having diagnostic or nondiagnostic quality. Digital radiographs had a significantly lower number of image artifacts and significantly higher frequency of proper labeling versus film radiographs.

Conclusions and Clinical Relevance—Results of this study suggested the technical variables proper exposure, proper positioning, absence of artifacts, and acquisition of all appropriate views were important for acquisition of sets of radiographs of high diagnostic quality. Identification of these errors and adjustment of radiographic technique to eliminate such errors would aid veterinarians in obtaining radiographs of high diagnostic quality and may reduce misinterpretation.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To perform repeated anterior chamber fluorophotometry on both eyes of ophthalmologically normal dogs to measure fluorescein concentrations over a 5-day period and identify any change in the degree of anterior chamber fluorescence over time or difference between eyes.

Animals—9 healthy adult dogs (18 eyes).

Procedures—Each dog received an IV injection of 10% fluorescein solution, and anterior chamber fluorophotometry was performed 1 hour later on both eyes. This procedure was repeated at the same time each day for 5 consecutive days.

Results—A significant increase in fluorescein concentration was evident in the anterior chamber on day 5 in the right eye and days 2, 3, 4, and 5 in the left eye. There was no significant difference in concentration between the left and the right eyes on any day.

Conclusions and Clinical Relevance—The increase in ocular fluorescein concentration in the study dogs was unlikely to be of clinical importance and is only pertinent for subsequent research studies. This is a limitation that should be considered when reporting fluorophotometry data as fluorescein concentration or as change in fluorescein concentration from baseline.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To measure strain in the common calcaneal tendon during trotting in dogs and to compare strain before and after immobilization of the tarsal joint.

Animals—6 dogs.

Procedures—A microminiature strain gauge was surgically implanted on the tendinous portion of the gastrocnemius muscle. Surface electromyography (EMG) values, percentage strain, and ground reaction forces were measured before and after immobilization. Peak vertical force; vertical impulse; initial, maximum, and final strain; and peak-to-peak EMG amplitude were recorded. Data were analyzed by use of a repeated-measures ANOVA and paired t tests.

Results—Timing of strain data correlated closely with foot strike of the hind limb and EMG activity in all dogs. Maximum tendon strain was simultaneous with peak vertical force. Continued muscle contraction was evident after immobilization. There was no significant difference in maximum strain after immobilization, compared with maximum strain during normal motion. Minimum strain, both at the beginning and end of the strain curve, was sig-nificantly decreased for the immobilized state, compared with results for nonimmobilized joints.

Conclusions and Clinical Relevance—Immobilization of the tarsal joint did not eliminate calcaneal tendon strain during weight bearing in dogs. Decreased isometric muscle contraction during the swing phase of the gait could account for smaller minimum strain in immobilized joints. Immobilization is frequently applied after Achilles tendon rupture to alleviate strain and force on the sutured repair, with possible complications because of the immobilization method. Consideration of these findings could be important in adjusting current treatment recommendations.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the local and systemic effects of IM implantation of lead shot alternatives in rats.

Animals—22 laboratory rats.

Procedures—Sterile IM implantation of shot metals was performed, with euthanasia and necropsy at 2, 8, 16, and 26 weeks after implantation. Skeletal muscle specimens were examined histologically and kidney specimens were tested for heavy metals. In vivo and in vitro evaluation of corrosion of metals was performed.

Results—Corrosion of susceptible metals was greatest at 2 weeks in vivo and in vitro. Inflammation associated with all pellet types was greatest 2 weeks after implantation. Nickel-plated steel incited significantly greater inflammation at 2 weeks, compared with bismuth alloy. Kidney iron concentration was significantly greater at 26 weeks, compared with other test periods. Local tissue deposition of iron was verified by use of Prussian blue staining for all iron-containing metals. Concentration of arsenic in kidneys was significantly greater at 8, 16, and 26 weeks after implantation, compared with 2 weeks.

Clinical Relevance and Impact for Human Medicine—Humans or dogs wounded with nickel-plated steel may require more aggressive initial monitoring than those wounded with other shot types. Monitoring of systemic arsenic concentrations may be indicated in patients wounded with shotgun pellets.

Full access
in American Journal of Veterinary Research