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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
in Journal of the American Veterinary Medical Association

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 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

Abstract

OBJECTIVE

To assess single-day and multiday repeatability of weight distribution (stance) data obtained with a commercial analyzer for dogs with naturally occurring hind limb lameness.

ANIMALS

46 dogs (15 and 31 for single-day and multiday trials, respectively).

PROCEDURES

For single-day trials, 5 to 10 measurements/trial were collected to determine body weight (BW), weight distribution on each limb, and forelimb and hind limb symmetry indices (SIs). The dog was removed from the room and returned immediately; 5 trials were performed. For multiday trials, measurements were performed in the same manner on 2 sequential days. Data were compared among trials (single-day measurements) and between days (multiday measurements). Repeatability (correlation coefficients and Lin concordance correlation coefficients [LCCCs]) and variability (coefficients of variation [CVs]) were assessed.

RESULTS

In single-day trials, BW (r = 0.999), weight distribution on the lame hind limb (r = 0.915) and contralateral hind limb (r = 0.948), and hind limb SI (r = 0.964) were each significantly correlated among trials. In multiday trials, BW results were similar; weight distribution on the lame hind limb and contralateral hind limb and hind limb SI were each less closely but still significantly correlated between days. The LCCCs were highest for BW, weight distribution on the contralateral hind limb, and hind limb SI in single-day trials and for BW and weight bearing on the contralateral and lame hind limbs in multiday trials. The CVs were lowest for BW and highest for forelimb SI in both trial types.

CONCLUSIONS AND CLINICAL RELEVANCE

The analyzer used allowed repeatable measurement of BW and weight distribution on the hind limbs of dogs with hind limb lameness. Measurement of forelimb stance variables was not repeatable in this group of dogs.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine the effect of topical ophthalmic administration of 0.005% latanoprost solution on aqueous humor flow rate (AHFR) and intraocular pressure (IOP) in ophthalmologically normal dogs.

ANIMALS

12 adult Beagles.

PROCEDURES

In a masked crossover design involving two 10-day experimental periods separated by a 7-day washout period, dogs were randomly assigned to first receive latanoprost or artificial tears (control) solution and then the opposite treatment in the later experimental period. Each experimental period was divided into a baseline phase (days 1 to 3), baseline fluorophotometry assessment (day 4), treatment phase (1 drop of latanoprost or artificial tears solution administered twice daily in each eye on days 5 to 9 and once on day 10), and posttreatment fluorophotometry assessment (day 10). Measured fluorescein concentrations were used to calculate baseline and posttreatment AHFRs. The IOP was measured 5 times/d in each eye during baseline and treatment (days 5 to 9) phases.

RESULTS

Mean baseline and posttreatment AHFR values did not differ significantly in either experimental period (latanoprost or control). In the latanoprost period, mean IOP was significantly lower during treatment than at baseline; there was no difference in corresponding IOP values during the control period. In the latanoprost period, mean IOP was significantly higher on the first day of treatment than on subsequent treatment days.

CONCLUSIONS AND CLINICAL RELEVANCE

In ophthalmologically normal dogs, topical ophthalmic administration of 0.005% latanoprost solution significantly decreased IOP but did not affect AHFR. Thus, the ocular hypotensive effect of latanoprost did not appear to have been caused by a reduction in aqueous humor production. (Am J Vet Res 2019;80:498–504)

Full 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