Pia Gustås

Incidence of intervertebral disk degeneration–related diseases and associated mortality rates in dogs

OBJECTIVE To determine the incidence and distribution of intervertebral disk (IVD) degeneration-related diseases in a large population of dogs of various breeds, ages, and sexes and to determine mortality rates among dogs with these diseases. DESIGN Epidemiological study. SAMPLE Insurance data for dogs with veterinary health-care and life insurance coverage (n = 665,249 and 552,120, respectively). PROCEDURES Insurance claim records of 1 company in Sweden were searched to identify dogs with IVD degeneration-related diseases; incidence and mortality rates were determined for affected dogs < 12 years old and < 10 years old, respectively. Only the first paid IVD degeneration-related claim for a dog was included in incidence rate calculations. RESULTS The incidence rate of IVD degeneration-related diseases was 27.8 (95% confidence interval [CI], 27.2 to 28.4) occurrences/10,000 dog-years at risk (DYAR), indicating that approximately 0.3% of dogs/y in this population were affected. Miniature Dachshund was the most highly represented breed, followed by Standard Dachshund and Doberman Pinscher (237.1 [95% CI, 212.9 to 261.4], 141.5 [95% CI, 135.5 to 147.4], and 88.6 [95% CI, 72.1 to 105.2] occurrences/10,000 DYAR, respectively). The incidence rate of IVD degeneration-related disease was greater in male than in female dogs and increased with age. Overall mortality rate attributed to IVD degeneration-related diseases was 9.4 (95% CI, 8.9 to 9.8) deaths/10,000 DYAR and was greater in males than in females. CONCLUSIONS AND CLINICAL RELEVANCE Differences in incidence rates among various breeds suggested a genetic involvement. Knowledge of the distribution of IVD degeneration-related diseases among dogs of various breeds and ages may facilitate early diagnosis and preemptive treatments in patients at risk for developing these diseases.

Relationships between fore- and hindlimb ground reaction force and hoof deceleration patterns in trotting horses.

REASONS FOR PERFORMING STUDY The transmission of shockwaves following hoof impact is proposed to be one major source of stress to the limb. In the forelimb, there are indications that the period of horizontal deceleration of the hoof is related to the attenuation of shockwaves. In the hindlimb, information about the hoof deceleration has been lacking. OBJECTIVE To compare hoof deceleration patterns between the fore- and hindlimbs. METHODS Seven Standardbreds were trotted by hand over a force plate covered with sand, with triaxial accelerometers mounted on the fore and hind hooves. Variables representative of decelerations (first 2 main vertical deceleration peaks; characteristic minimum and maximum values in the craniocaudal deceleration; hoof braking time) and ground reaction forces (vertical loading rates; maximum and the following local minimum of the craniocaudal force) of the initial part of the stance phase, and the differences between individual fore- and hindlimb time and amplitude variables were used for statistical analyses. RESULTS Force plate data showed significantly greater vertical loading rate (mean +/- s.d. 6.5 +/- 5.9 N/sec) and horizontal loads (190.4 +/- 110.2 N) in the forelimb than the hindlimb, but the parameters from accelerometer data showed no significant differences. CONCLUSIONS No significant difference was found in the hoof deceleration, but the deceleration curves displayed a common pattern that described in detail the kinematics of the fore and hind hooves during the initial period of hoof braking. POTENTIAL RELEVANCE These results contribute to further knowledge about the characteristics of these potential risk factors in the development of subchondral bone damage in the horse. Further studies are required on the influence of hoof braking pattern at higher speed, different shoeing and ground surfaces with different properties.

Ground reaction force and hoof deceleration patterns on two different surfaces at the trot

The objective of the present study was to compare the hoof deceleration and ground reaction forces following impact on two different surfaces. Seven unshod Standardbreds were trotted by hand at 3.0–5.7 m s over a force plate covered by either of the two surfaces, sandpaper or a 1 cm layer of sand. Impact deceleration data were recorded from one triaxial accelerometer mounted on the foreand hind hooves, respectively. Ground reaction force data were obtained synchronously from a force plate, sampled at 4.8 kHz. The differences between the two surfaces were studied by analysing representative deceleration and force variables for individual horses. The maximum horizontal peak deceleration and the loading rates of the vertical and the horizontal forces were significantly higher on sandpaper compared with the sand surface (P , 0.001). In addition, the initial vertical deceleration was significantly higher on sandpaper in the forelimb (P , 0.001). In conclusion, it was shown that the different qualities of the ground surface result in differences in the hoof-braking pattern, which may be of great importance for the strength of the distal horse limb also at slow speeds.

Soft tissue artifact in canine kinematic gait analysis

OBJECTIVE To investigate, noninvasively, the soft tissue artifact (STA) in canine kinematic gait analysis. STUDY DESIGN Experimental study. ANIMALS Labrador retrievers (n = 4). METHODS Kinematic study: Reflective markers were glued to the skin over bony landmarks, with the distance between 2 markers representing the length of the underlying scapula, humerus, ulna, femur, and crus. The distance between these markers (marker distance [MD]) was measured with infrared cameras while the dogs stood still or walked on a treadmill. Fluoroscopy study: Radiopaque markers were glued on the skin over the spinous process of the L6 vertebra and the stifle to allow fluoroscopic observation of the markers and underlying skeletal segments while the dogs walked on the treadmill. The position of the markers was compared with the position of the underlying skeletal segments during different phases of the step cycle. RESULTS Kinematic study: Significant differences were found between MD during standing and walking for all bones investigated. Mean percentage differences in MD ranged from -18% to +6%. Fluoroscopy study: Significant displacements relative to the bony landmarks were found ranging from 0.4 to 1.2 cm. CONCLUSIONS Analysis of the motion of skeletal structures with the use of markers attached to the skin showed that the skin moves relative to underlying skeletal structures. When working with a 3-D motion-capture system using skin markers, researchers should be aware that the STA could significantly influence their results.

A field study on hoof deceleration at impact in Standardbred trotters at various speeds

Impact-related peak decelerations with high loading rates are described as indicators of mechanical stress to the limb. The hoof deceleration pattern in the beginning of the stance phase has recently been described, together with ground reaction force measurements at slow speed; however, no information is available at high speeds. The objective of the present study was to investigate the hoof deceleration pattern following impact at slow speeds, comparable to earlier force plate studies, and at high speeds on a racetrack. Eight Standardbreds equipped with triaxial accelerometers mounted on fore- and hind hooves were driven from a jogcart on a harness-training racetrack with a stone dust surface at the mean speeds of 4.7, 5.7, 10.1 and 12.7ms −1 . The accelerometer signals were sampled at 10kHz during 10s of constant speed along one straight of the racetrack. The signal was studied for each speed by the analysis of representative peak decelerations. At slow trot, the deceleration pattern was similar to what was found in earlier studies over the force plate. The peak values of both the vertical and horizontal decelerations increased significantly with a higher speed ( P ≤0.01). It was shown that a higher speed results in changes of the hoof deceleration pattern with higher peak decelerations. The maximum horizontal deceleration, together with the second vertical peak deceleration, were suggested to be major indicators on the mechanical stress subjected to the limb.

Kinematic and temporospatial assessment of habituation of Labrador retrievers to treadmill trotting.

This study investigated differences in kinematic and temporospatial variables in treadmill-naïve dogs when introduced to treadmill trotting and the time required to for them to become habituated to the treadmill. Twenty-four healthy Labrador retrievers, with an age range of 22-36 months and with no history of orthopaedic disease, were included in the study. A motion capture system registered kinematic variables of the carpus, elbow, tarsus and stifle, along with stride time and stance duration, at 240 Hz. Six sessions, each lasting 8-10 min, walking and trotting on the treadmill were performed with each dog, with three sessions on each of two consecutive days. The between-stride variability of total angular displacement of the carpus, elbow, stifle and tarsus, as well as the stride and stance time, was higher during the day 1 trotting sessions than in the last session of day 2. These stabilised to non-significant levels before the second session on the second day of measurements and thus habituation was achieved.

Comparison of Polar® RS800CX heart rate monitor and electrocardiogram for measuring inter-beat intervals in healthy dogs

UNLABELLED The aim of the present study was to assess the criterion validity, relative reliability and level of agreement of Polar® RS800CX heart rate monitor measuring inter-beat intervals (IBIs), compared to simultaneously recorded electrocardiogram (ECG) in dogs. METHODS Five continuous minutes of simultaneously recorded IBIs from Polar® RS800CX and Cardiostore ECG in 11 adult healthy dogs maintaining standing position were analyzed. Polar® data was statistically compared to ECG data to assess for systematic differences between the methods. Three different methods for handling missing IBI data were used. Criterion validities were calculated by intraclass correlation coefficients (ICCs) and corresponding 95% confidence intervals (CIs). Relative reliabilities and levels of agreement were calculated by ICCs and the Bland and Altman analysis for repeated measurements per subject. RESULTS Correlation coefficients between IBI data from ECG and Polar® RS800CX varied between 0.73 and 0.84 depending on how missing values were handled. Polar® was over- and underestimating IBI data compared to ECG. The mean difference in log transformed (base10) IBI data was 0.8%, and 93.2% of the values were within the limits of agreement. Internally excluding three subjects presenting IBI series containing more than 5% erroneous IBIs resulted in ICCs between 0.97 and 0.99. Bland and Altman analysis (n=8) showed mean difference was 1.8ms, and 98.5% of the IBI values were plotted inside limits of agreement. CONCLUSION This study showed that Polar® systematically biased recorded IBI series and that it was fundamental to detect measurement errors. For Polar® RS800CX heart rate monitor to be used interchangeably to ECG, by showing excellent criterion validity and reliable IBI measures in group and individual samples, only less than 5% of artifacts could be accepted.

Psychometric evaluation of the canine brief pain inventory in a Swedish sample of dogs with pain related to osteoarthritis

BackgroundTo evaluate intervention, implement evidence-based practice and enhance the welfare of dogs with naturally occurring osteoarthritis (OA), access to valid, reliable and clinically relevant outcome measures is crucial for researchers, veterinarians and rehabilitation practitioners. The objectives of the present study were to translate and evaluate psychometric properties, in terms of internal consistency and construct validity, of the owner-reported measure canine brief pain inventory (CBPI) in a Swedish sample of dogs with pain related to OA.ResultsTwenty-one owners of clinically sound dogs and 58 owners of dogs with pain related to OA were included in this observational and cross-sectional study. After being translated according to the guidelines for patient-reported outcome measures, the CBPI was completed by the canine owners. Construct validity was assessed by confirmatory factor analysis, by repeating the principal component analysis and by assessing for differences between clinically sound dogs and dogs with pain related to OA. Internal consistency was estimated by Cronbach’s α. Confirmatory factor analysis was not able to confirm the factor-structure models tested in our sample. Principal component analysis showed a two-component structure, pain severity and pain interference of function. Two components accounted for 76.8% of the total variance, suggesting an acceptable fit of a two-component structure. The ratings from the clinically sound dogs differed from OA dogs and showed significantly lower CBPI total sum. Cronbach’s α was 0.94 for the total CBPI, 0.91 for the pain severity and 0.91 for the pain interference of function.ConclusionsThe results indicate that the translated version of the CBPI is valid for use in the Swedish language. The findings suggest satisfying psychometric properties in terms of high internal consistencies and ability to discriminate clinically sound dogs from OA dogs. However, based on the confirmatory factor analysis, the original factor structure in the CBPI is not ideally suited to measure pain related to OA in our sample and the hypothesis of the presented two-factor structure was rejected. Further research needs to be conducted to determine whether the original psychometric results from CBPI can be replicated across different target groups and particularly with larger sample size.