Objective—To characterize the gait of small-breed dogs walked on a pressure walkway by handlers moving at a metronome-set tempo and to determine the influence of handler and leash side on gait characteristics.
Procedures—Dogs were walked by each of 5 handlers moving at a metronome-set tempo (100 beats/min). Velocity, cadence, stance time, number of activated sensors, total pressure index (TPI), left or right hind reach, and symmetry indices were obtained with the leash on the left and right sides of each dog for each handler.
Results—Coefficients of variation for TPI and stance time approximated 30%, whereas coefficients of variation for symmetry indices remained < 20%. Changing handlers and leash side did not influence hind limb variables. Changing handlers influenced the TPI of the forelimbs, inducing changes of up to 8%. Leash side accounted for 12% and 14% of the variation in symmetry indices of TPI and number of sensors activated between forelimbs, respectively (mean alterations for recorded variables, 9%).
Conclusions and Clinical Relevance—Symmetry indices appeared to vary less than variables obtained for individual dog limbs, and it may therefore be advantageous to determine those indices during large trials. Handlers or leash side may be changed in studies focusing on dogs’ hind limbs without affecting results. Use of symmetry indices is recommended in forelimb studies requiring multiple handlers. Pressure walkway analyses of the forelimbs should include equal distribution of left- and right-sided leash-led trials, given that small-breed dogs tended to shift weight toward the forelimb opposite the leash.
Objective—To evaluate skeletal characteristics of pelvic limbs with and without cranial cruciate ligament (CCL) deficiency in Labrador Retrievers.
Animals—30 adult purebred Labrador Retrievers.
Procedures—Pelvic limbs (n = 28) of 14 dogs without CCL deficiency were classified as control limbs, whereas the limbs of 16 dogs with CCL deficiency were considered affected by (18 limbs) or predisposed to (10 contralateral limbs of dogs with 1 affected limb) CCL deficiency. Skeletal characteristics were evaluated via physical examination, radiography, and computed tomography. Radiographic and computed tomographic variables were compared among limb groups by use of a mixed-model ANOVA.
Results—The tibial plateau slope was steeper in CCL-deficient limbs but not in predisposed limbs, compared with the slope in control limbs. The angle between diaphyseal and proximal tibial axes was increased in both CCL-deficient and predisposed limbs. The relative width of the proximal portion of the tibia and the inclination of the patellar ligament did not differ among limb groups. The overall and distal femoral anteversion angles were greater in CCL-deficient and predisposed limbs, whereas the femoral condyle trochanteric angle was decreased in those limb groups, compared with findings in control limbs.
Conclusions and Clinical Relevance—Cranial angulation of the proximal portion of the tibia, excessive steepness of the tibial plateau, and distal femoral torsion appeared more likely to be associated with CCL deficiency than femoral angulation, tibial torsion, intercondylar notch stenosis, and increased inclination of the patellar ligament.
Objective—To evaluate effects of small intestinal submucosa (SIS) on elution properties of plaster of Paris (POP).
Sample Population—27 POP cylinders, 27 POP spheres, and 9 polymethylmethacrylate (PMMA) spheres.
Procedures—Pellets were loaded with gentamicin (50 mg/g) and divided into 7 groups of 9 beads each: PMMA spheres; POP cylinders coated with 0, 4, or 8 layers of SIS; and POP spheres coated with 0, 4, or 8 layers of SIS. Gentamicin concentration was measured 6, 12, 18, 24, 32, 40, and 48 hours and 3, 4, 5, 7, 14, 21, 28, 35, and 42 days after wrapping. Porosity was evaluated via scanning electron microscopy. Curvature factor of elution curves, total amount of drug released (TDR), time required to reach 50% of total release (TDRt50), and number of days with concentrations ≥ 1 μg/mL were compared among groups.
Results—SIS decreased the curvature factor and increased the TDRt50 and TDR of POP spheres and cylinders. Curvature factor of the PMMA-release curve remained lower than that for any POP group, but all POP groups wrapped in SIS released more gentamicin than PMMA spheres. Gentamicin concentrations remained ≥ 1 μg/mL in SIS-wrapped POP and PMMA groups throughout the study. Wrapping POP in SIS minimized the increase in porosity of pellets.
Conclusions and Clinical Relevance—Wrapping POP with SIS slows the release and increases the amount of gentamicin leaching from spheres and cylinders. All groups wrapped in SIS maintained antimicrobial concentrations greater than the minimum inhibitory concentration of most pathogens.
To gather and evaluate veterinarians' perspectives about the impacts of the COVID-19 pandemic on the use of veterinary telehealth and on cat owners' versus dog owners' attitudes toward transmission of the SARS-CoV-2 virus from their pets.
93 respondent veterinarians (47 in primary care practice and 46 in specialty practice).
An online survey was conducted between June 15 and July 15, 2020, and included 21 questions concerning demographics, use of telehealth before and after the onset of the pandemic (before March 15, 2020, and between March 15 and June 15, 2020, respectively), changes in caseloads, and perception of clients' concerns about potential for transmission of the SARS-CoV-2 virus from pets. Reported zip codes informed the collection of census data.
The level of poverty was significantly lower in zip code areas for respondents who reported telehealth services were (vs were not) offered before the pandemic. The percentage of respondents who reported their practice offered telehealth services increased from 12% (11/93) before the pandemic to 38% (35/93) between March 15 and June 15, 2020. Although most respondents reported owner-expressed concerns over SARS-CoV-2 virus transmission from their pets, most also reported increased caseloads, seeing newly adopted pets, and few discussions of surrender of pets for reasons related to the SARS-CoV-2 virus.
CONCLUSIONS AND CLINICAL RELEVANCE
Findings indicated that caseloads increased and telehealth services expanded during the pandemic but that there was no evidence of differences in respondent-reported owner concern for SARS-CoV-2 virus transmission from cats versus dogs.
Animals—80 dogs with naturally occurring unilateral cranial cruciate ligament disease.
Procedures—All dogs were randomly assigned to undergo LFS (n = 40) or TPLO (40). Clinical data collected included age, weight, body condition score, history information, stifle joint instability, radiographic findings, surgical findings, and complications. Outcome measures were determined prior to surgery and at 6 and 12 weeks and 6 and 12 months after surgery, including values of pressure platform gait analysis variables, Canine Brief Pain Inventory scores, owner satisfaction ratings, thigh circumference, and stifle joint goniometry values.
Results—Signalment and data for possible confounding variables were similar between groups. Peak vertical force of affected hind limbs at a walk and trot was 5% to 11% higher for dogs in the TPLO group versus those in the LFS group during the 12 months after surgery. Canine Brief Pain Inventory, goniometry, and thigh circumference results indicated dogs in both groups improved after surgery, but significant differences between groups were not detected. Owner satisfaction ratings at 12 months after surgery were significantly different between groups; 93% and 75% of owners of dogs in the TPLO and LFS groups indicated a satisfaction score ≥ 9 (scale, 1 to 10), respectively.
Conclusions and Clinical Relevance—Kinematic and owner satisfaction results indicated dogs that underwent TPLO had better outcomes than those that underwent LFS.
Objectives—To compare combined vacuum and rotation
with the spinner flask technique for seeding
chondrocytes on chitosan versus polyglycolic acid
Sample Population—Porcine chondrocytes.
Procedure—A suspension containing 5 × 106 chondrocytes/
scaffold was used to evaluate 2 seeding
techniques, including a spinner flask and a customdesigned
vacuum chamber used for 2 hours prior to
transfer to a bioreactor. For each seeding technique,
prewetted scaffolds were composed of polyglycolic
acid (PGA) mesh or macroporous chitosan sponge.
Constructs were collected at 48 hours for DNA quantification,
measurement of water and gycosaminoglycan
(GAG) content, and scanning electron
Results—Yield of both seeding techniques was similar
for each type of scaffold. Percentage of cells contained
in the center of PGA constructs was increased
with seeding in the bioreactor (43% of total cell number),
compared with the spinner flask (18%). The DNA
content and cell number per construct were 10 times
greater for PGA constructs, compared with chitosan
constructs. Chitosan scaffolds seeded in the bioreactor
yielded a significantly higher GAG:DNA ratio than
did PGA scaffolds. Whereas chondrones formed on
chitosan scaffolds, cell distribution was more uniform
on PGA scaffolds.
Conclusions and Clinical Relevance—The vacuumbioreactor
technique allowed seeded chondrocytes to
attach to PGA scaffolds within 48 hours and improved
uniformity of cell distribution, compared with the
spinner technique. Although formation of extracellular
matrix may be stimulated by seeding chitosan scaffolds
in the bioreactor, further evaluations of the seeding
technique and characteristics of chitosan scaffolds
are warranted. (Am J Vet Res 2005;66:599–605)
Objective—To establish the dose-dependent effects of high-molecular-weight hyaluronic acid (HA) supplementation on chondrogenesis by mesenchymal stem cells (MSCs) cultured on chitosan sponges and to determine the extent to which MSC matrix production (chondrogenesis) can be influenced by incorporation of high-molecular-weight HA into chitosan scaffolds.
Sample Population—Murine MSCs derived from a multipotent bone marrow stromal precursor.
Procedures—MSCs were seeded on chitosan and chitosan-HA scaffolds in chondrogenic medium with various HA concentrations. Scanning electron microscopy, fluorescence microscopy (viability assay), and DNA quantification were used to assess cell attachment, distribution, and viability 48 hours after seeding. Constructs were cultured for 3 weeks prior to evaluation of cell distribution and chondrogenic differentiation via histologic evaluation and quantification of DNA, glycosaminoglycan, and collagen II.
Results—48 hours after MSC seeding, cell viability and DNA content were similar among groups. Three weeks after seeding, HA supplementation of the culture medium improved matrix production in a dose-dependent manner, as indicated by matrix glycosaminoglycan and collagen II concentrations. The scaffold composition, however, had no significant effect on matrix production.
Conclusions and Clinical Relevance—High-molecular-weight HA supplementation in culture medium had a dose-dependent effect on matrix production and thus chondrogenic differentiation of MSCs cultured on chitosan sponges. The addition of HA in the surrounding fluid during chondrogenesis should improve cartilage production and may be useful for producing engineered cartilage tissues.
Population—25 students completing the second year of their veterinary curriculum.
Procedures—Students were randomly assigned to 2 groups to receive 14 hours of specific training in either open ovariectomy (n = 13) or laparoscopic ovariectomy (12). Confidence, basic surgical skills, and basic laparoscopic skills were evaluated before and after training, prior to live surgical procedures.
Results—Scores related to basic surgical skills were high in both groups and did not improve with either training program. Before live animal surgeries, student confidence and basic laparoscopic skills improved after training in laparoscopic ovariectomy and were higher than after training in open ovariectomy. Surgery time was higher for the students who received training in laparoscopic ovariectomy (129 minutes; range, 84 to 143 minutes), compared with students who received training in open ovariectomy (80 minutes; range, 62 to 117 minutes). On a 55-point scoring system, ovariectomy scores were similar between students who received training in open ovariectomy (34.5; range, 16.5 to 45) and students who received training in laparoscopic ovariectomy (34.5; range, 25 to 44.5).
Conclusions and Clinical Relevance—The training programs were effective in improving student confidence and skills in laparoscopic ovariectomy. Results of this study suggested that veterinary medical students, with assistance from an instructor, may be taught to perform laparoscopic ovariectomies with performance equivalent to that for students performing open ovariectomies.
Objective—To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD).
Animals—Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD.
Procedures—The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> −1.5]) or not predisposed (low score [≤ −1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed.
Results—The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups.
Conclusions and Clinical Relevance—Gait mechanics of dogs with high (> −1.5) and low (≤ −1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.