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Abstract
OBJECTIVE
To determine the reliability of range-of-motion (ROM) measurements and describe physiologic differences in ROM or habituation effects during gait analysis of healthy dogs walking on a treadmill.
ANIMALS
11 orthopedically normal dogs.
PROCEDURES
ROM of appendicular joints was determined for each dog while walking on a treadmill on 3 consecutive examination days and once again 6 weeks later. Significant differences in ROM between examination days were determined and quantified. As a measure of reproducibility, the coefficient of variation for repeated measurements was calculated, as were the minimum differences necessary to distinguish between physiologic variation and true change in ROM.
RESULTS
Mean ROM of the shoulder, elbow, and carpal joints varied among examination days between 29.9° and 33.1°, 49.4° and 52.8°, and 7.7° and 88.1°, respectively. Mean associated minimum differences were 12.0°, 14.1°, and 35.6°. Mean ROM of the hip, knee, and tarsal joints varied between 32.9° and 35.8°, 33.7° and 36.8°, and 31.7° and 33.5°, respectively. Mean associated minimum differences were 16.2°, 14.0°, and 9.2°. Only ROM of the elbow joint was reproducible to a small degree. Few systematic effects were detected.
CONCLUSIONS AND CLINICAL RELEVANCE
Measurement of ROM in healthy dogs walking on a treadmill was shown to be diagnostically unreliable owing to high variation among examination days. However, random physiologic fluctuations could be distinguished from systematic effects, demonstrating the importance of reliably applicable threshold values for follow-up treadmill examinations. The applicability of the minimum differences determined here to orthopedically diseased dogs remains to be determined.
Abstract
OBJECTIVE
To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway.
ANIMALS
5 nonlame adult light-breed horses.
PROCEDURES
Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile–low surface area calks, with low profile–high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments.
RESULTS
Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile–high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.
Abstract
OBJECTIVE
To evaluate synoviocentesis of the equine forelimb digital flexor tendon sheath (DFTS) via a basilar sesamoidean approach (BSA) or distal approach (DA).
ANIMALS
21 healthy adult horses without DFTS-related lameness.
PROCEDURES
The forelimbs of each horse underwent the BSA or DA (21 limbs/approach) performed by 1 individual. The volume of synovial fluid (SF) aspirated, time from skin puncture to collection of SF, and number of attempts to place a needle in the DFTS were compared between approaches.
RESULTS
An SF sample was successfully aspirated from 16 of 21 (76%) limbs with the BSA and 20 of 21 (95%) limbs with the DA. For the BSA and DA, the number of attempts to obtain SF was 2 and 1, respectively; the median volume of SF obtained was 0.4 and 0.7 mL, respectively; and the median time to SF collection was 17.91 and 18.48 seconds, respectively. Between the approaches, the number of limbs with SF successfully aspirated and number of attempts to collect SF differed significantly, whereas the volume of SF aspirated and time to SF collection did not.
CONCLUSIONS AND CLINICAL RELEVANCE
Regarding SF collection from forelimb DFTSs in horses without DFTS-related disease, use of the DA had a greater success rate with fewer attempts, compared with findings for the BSA, which may reflect the relative ease of identifying anatomic landmarks for the DA. Results suggested that a DA for DFTS synoviocentesis in horses appears efficient and effective and may minimize limb trauma by requiring fewer attempts for SF sample collection, compared with a BSA.
Abstract
OBJECTIVE
To investigate the effects of triamcinolone acetonide (TA) and methylpredniso-lone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses.
SAMPLE
12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculo-skeletal disease.
PROCEDURES
Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or 5 mg/mL) medium for 6 or 24 hours. Explant metabolic activity and percentage of dead cells were assessed with a resazurin-based assay and live-dead cell staining, respectively, at each time point. Drug effects were assessed relative to findings for the respective control group.
RESULTS
Application of TA (at both concentrations) did not significantly change the cell viability of FC-DDFT explants. For FC-NB explants, TA at 6 mg/mL significantly reduced the metabolic activity and increased the percentage of dead cells at both time points. With either MPA concentration, FC-DDFT and FC-NB explants had reduced metabolic activity and an increased percentage of dead cells at 24 hours, whereas only MPA at 5 mg/mL was cytotoxic at the 6-hour time point.
CONCLUSIONS AND CLINICAL RELEVANCE
In ex vivo explants, TA was less cytotoxic to equine FC-DDFT and FC-NB cells, compared with MPA. Further work is warranted to characterize the drugs' transcriptional and translational effects as well as investigate their cytotoxicity at lower concentrations.
Abstract
OBJECTIVE
To investigate whether an actual improvement in gait could be differentiated from physiologic differences or habituation effects during gait analysis of dogs.
ANIMALS
11 healthy dogs.
PROCEDURES
On 4 examination days, kinetic parameters were measured while dogs were walking on a treadmill. Differences in mean parameter values and habituation effects (ie, effect sizes) were quantified and compared among examination days. Coefficients of variation for repeated measurements were calculated to determine measurement reproducibility, and minimum differences were calculated to distinguish between physiologic fluctuation and an actual change in gait pattern.
RESULTS
Among the 4 examination days, mean absolute differences in peak vertical force and vertical impulse (VI) varied from 1.5% to 5.3% of body weight (BW) and 0.9% to 1.8% of BW·s, respectively. Mean absolute differences in the percentage of stance-phase duration (%SPD) and relative stride length (RSL) varied from 0.9% to 3.2% and 1.7% to 3.0%, respectively. Reproducibility of parameter measurements was good. Values for %SPD had the lowest amount of dispersion and largest effect size, suggesting a habituation effect for this parameter. Calculated minimum differences among the days for peak vertical force, VI, %SPD, and RSL did not exceed 9.9% of BW, 3.3% of BW·s, 5.8 percentage points, and 5.2 percentage points, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE
The %SPD of healthy dogs walking on a treadmill was the most sensitive and diagnostically reliable of the measured kinetic parameters, in contrast to VI and RSL. Findings suggested that actual changes can be distinguished from random physiologic fluctuations during gait analysis of dogs.
Abstract
OBJECTIVE
To compare muscle condition scores (MCSs) and muscle ultrasonographic measurements in cats with and without muscle loss and to evaluate repeatability and reproducibility of MCS assessment.
ANIMALS
40 cats of various ages, body condition scores (BCSs), and MCSs.
PROCEDURES
A prospective cross-sectional study was conducted. Body weight, BCS, MCS, epaxial muscle height (EMH), vertebral epaxial muscle score (VEMS), and forelimb epaxial muscle score (FLEMS) were assessed in each cat. The MCS for each cat was assessed 3 separate times by each of 5 raters.
RESULTS
The MCS was significantly correlated with EMH (r = 0.59), VEMS (r = 0.66), and FLEMS (r = 0.41). For MCS, the overall value of the κ coefficient for interrater agreement (reproducibility) was 0.43 and the overall value of the κ coefficient for intrarater agreement (repeatability) ranged from 0.49 to 0.76.
CONCLUSIONS AND CLINICAL RELEVANCE
Ultrasonographic measurements of muscle may be useful for assessing muscle loss in individual cats over time. However, for the cats of this study, no advantage was observed for assessment of VEMS or FLEMS over EMH. Substantial repeatability and moderate reproducibility were shown when MCS was used for assessment of muscle mass in cats. Prospective ultrasonographic studies are warranted to evaluate the usefulness of MCS and EMH assessment for evaluation of changes in muscle mass of cats over time.
Abstract
OBJECTIVE
To determine the holding capacity of a 5.5-mm-diameter cortical bone screw when placed in the third phalanx (P3) of horses and assess whether screw placement through the dorsal hoof wall into P3 would be tolerated by clinically normal horses and would alleviate signs of pain and prevent P3 rotation in horses with oligofructose-induced laminitis.
ANIMALS
40 limbs from 10 equine cadavers and 19 clinically normal adult horses.
PROCEDURES
In part 1 of a 3-part study, a 5.5-mm-diameter cortical bone screw was inserted by use of a lag-screw technique through the dorsal hoof wall midline into P3 of 40 cadaveric limbs and tested to failure to determine screw pullout force. In part 2, 6 horses had 5.5-mm-diameter cortical bone screws placed in both forefeet as described for part 1. Screws were removed 4 days after placement. Horses were monitored for lameness before and for 2 weeks after screw removal. In part 3, 13 horses were randomly assigned to serve as controls (n = 3) or undergo screw placement without (group 2; 6) or with (group 3; 4) a washer. Following the acquisition of baseline data, horses were sedated and administered oligofructose (10 g/kg) via a stomach tube. Twenty-four hours later, screws were placed as previously described in both forefeet of horses in groups 2 and 3. Horses were assessed every 4 hours, and radiographic images of the feet were obtained at 96 and 120 hours after oligofructose administration. Horses were euthanized, and the feet were harvested for histologic examination.
RESULTS
The mean ± SD screw pullout force was 3,908.7 ± 1,473.4 N, and it was positively affected by the depth of screw insertion into P3. Horses of part 2 tolerated screw placement and removal well and did not become lame. All horses of part 3 developed signs of acute lameness, and the distance between P3 and the dorsal hoof wall increased slightly over time. The change in the ratio of the dorsal hoof wall width at the extensor process of P3 to that at the tip of P3 over time was the only variable significantly associated with treatment.
CONCLUSIONS AND CLINICAL RELEVANCE
Placement of a 5.5-mm-diameter cortical bone screw through the dorsal hoof wall into P3 had sufficient holding power to counteract the pull of the deep digital flexor tendon in approximately 500-kg horses, and placement of such a screw was well tolerated by clinically normal horses but did not alleviate signs of pain in horses with oligofructose-induced laminitis. Further research is necessary before this technique can be recommended for horses with naturally occurring acute laminitis.
Abstract
OBJECTIVE
To determine the effects of 3 α2-adrenergic receptor agonists (α2-ARAs), alone or in combination with butorphanol tartrate, on objective measurements of lameness in horses.
ANIMALS
17 adult polo horses with naturally occurring forelimb or hind limb lameness (or both).
PROCEDURES
In a crossover design, each horse received each protocol (saline [0.09% NaCl] solution [2 mL, IV] or xylazine hydrochloride [0.33 mg/kg, IV], detomidine hydrochloride [0.007 mg/kg, IV], or romifidine hydrochloride [0.033 mg/kg, IV] alone or in combination with butorphanol [0.007 mg/kg, IV]) in random order, with a washout period (≥ 7 days) between protocols. Horses were assessed immediately prior to (baseline) and 10, 15, 20, 30, and 40 minutes after administration of each protocol for degree of sedation, mechanical nociceptive threshold (MNT), and objective lameness measurements.
RESULTS
Compared with baseline values, sedation scores and MNTs were significantly higher at all evaluated time points following administration of all sedation protocols except xylazine alone; following administration of xylazine alone, sedation scores and MNTs were significantly higher at ≤ 30 minutes and ≤ 20 minutes, respectively. Significant differences in objective forelimb lameness measurements were noted after administration of the 3 α2-ARA-butorphanol combinations. Most significant differences in objective measurements of hind limb lameness were detected after administration of detomidine or romifidine, alone or in combination with butorphanol.
CONCLUSIONS AND CLINICAL RELEVANCE
In the study horses, xylazine alone had the least impact on objective lameness measurements. The administration of α2-ARAs, particularly detomidine or romifidine, alone or in combination with butorphanol, resulted in small but significant effects on objective lameness measurements.
Abstract
OBJECTIVE
To evaluate a novel prosthesis technique for extracapsular stabilization of cranial cruciate ligament (CCL)–deficient stifle joints in adult cattle.
SAMPLE
13 cadaveric bovine stifle joint specimens.
PROCEDURES
In the first of 3 study phases, the most isometric points on the distal aspect of the femur (distal femur) and proximal aspect of the tibia (proximal tibia) were determined from measurements obtained from lateromedial radiographs of a stifle joint specimen maintained at angles of 135°, 90°, 65°, and 35°. During phase 2, 800-lb-test monofilament nylon leader line was cut into 73-cm-long segments. Each segment was secured in a loop by use of 2, 3, or 4 crimping sleeves such that there were 12 replicates for each construct. Each loop was distracted to failure at a constant rate of 1 mm/s. Mean force at failure and elongation and mode of failure were compared among the 3 constructs. During phase 3, bone tunnels were created in the distal femur and proximal tibia at the isometric points identified during phase 1 in each of 12 CCL-deficient stifle joint specimens. The 3-sleeve construct was applied to each specimen. Specimens were distracted to failure at a constant rate of 1 mm/s.
RESULTS
Among the 3 constructs evaluated, the 3-sleeve construct was considered optimal in terms of strength and amount of foreign material. In phase 3, all replicates failed because of suture slippage.
CONCLUSIONS AND CLINICAL RELEVANCE
Use of 800-lb-test monofilament nylon leader line as a prosthesis might be a viable alternative for extracapsular stabilization of CCL-deficient stifle joints in adult cattle. Further in vivo studies are necessary.
Abstract
OBJECTIVE
To develop a low-technology system that can be used by dog owners to obtain morphological and mobility measurements in companion dogs as candidate components of an eventual canine frailty scale.
ANIMALS
57 adult (≥ 1-year-old) dogs enrolled by 43 owners.
PROCEDURES
Morphological measurements of dogs were performed by investigators and dog owners. Dogs participated in timed in-clinic mobility trials across a flat surface (on-leash trial with the owner, on-leash trial with the investigator, and off-leash trial) and on stairs; each trial was repeated 3 times. Owners were asked to conduct a second stair trial at home 2 weeks later. Agreement between owner- and investigator-obtained measurements was assessed with Shrout-Fleiss intraclass correlation coefficients and paired t tests. Age, quartile of projected percentage of mean life span attained (adjusted for body weight), and height were evaluated as predictors of speed and stride length in mobility trials with linear regression and Spearman rank correlation analysis.
RESULTS
Agreement between owner- and investigator-obtained morphological measurements was strong. Age was a weak but significant predictor of decreased dog speed in mobility trials (adjusted R 2, 0.10 to 0.23). Speed decreased significantly with increasing quartile of projected life span attained. A linear regression model that included height and age predicted dog speed better than models with age or height alone.
CONCLUSIONS AND CLINICAL RELEVANCE
Morphological and mobility trial measurements can be obtained by dog owners with minimal training. Low-technology measurements of mobility trial speed offer potential as components in a future scoring scale for canine frailty.