| 1. |
- Aspán, Anna, et al.
(author)
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Molecular Evidence for Persistence of Anaplasma phagocytophilum in the Absence of Clinical Abnormalities in Horses after Recovery from Acute Experimental Infection
- 2009
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In: Journal of Veterinary Internal Medicine. - : Wiley. - 0891-6640 .- 1939-1676. ; 23, s. 636-642
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Journal article (peer-reviewed)abstract
- Anaplasma phagocytophilum infects several mammalian species, and can persist in sheep, dogs, and calves. However, whether this organism persists in horses or induces long-term clinical abnormalities is not known.To evaluate whether A. phagocytophilum can persist in horses and to document clinical findings for 3 months after complete recovery from acute disease.Five clinically normal adult horses that had recovered spontaneously from experimentally induced acute disease caused by a Swedish equine isolate of A. phagocytophilum.Horses were monitored for up to 129 days post inoculation (PI) by daily clinical examination and at least alternate day blood sampling for evidence of A. phagocytophilum on polymerase chain reaction (PCR) and blood smears. All horses were euthanized and underwent postmortem examination.All horses were periodically PCR positive after recovery from acute infection. Before day 66 PI 2 horses were persistently PCR negative whereas 3 horses were intermittently PCR positive. Subsequently, 4 of 5 horses were intermittently PCR positive, particularly after stress mimicking interventions. One animal was positive immediately before postmortem examination. Clinical abnormalities related to persistence of anaplasma were not observed. No specific changes were found at postmortem examination, and all sampled tissues from all horses were negative on PCR for A. phagocytophilum.Infection with A. phagocytophilum can persist in the horse for at least 129 days. However, the continued presence of the organism is not associated with detectable clinical or pathological abnormalities.
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| 2. |
- Axner, Eva, et al.
(author)
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Dystocia in the cat evaluated using an insurance database
- 2017
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In: Journal of Feline Medicine and Surgery. - 1098-612X .- 1532-2750. ; 19, s. 42-47
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Journal article (peer-reviewed)abstract
- Objectives The aim of this study was to describe the incidence of feline dystocia with respect to breed.Methods The data used were reimbursed claims for veterinary care insurance and/or life insurance claims in cats registered in a Swedish insurance database from 1999-2006.Results The incidence rates for dystocia were about 22 cats per 10,000 cat-years at risk, 67 per 10,000 for purebred cats and seven per 10,000 for domestic shorthair cats. The median age was 2.5 years. A significant effect of breed was seen. An incidence rate ratio (IRR) that was significantly higher compared with other purebred cats was seen in the British Shorthair (IRR 2.5), the Oriental group (IRR 2.2), Birman (IRR 1.7), Ragdoll (IRR 1.5) and the Abyssinian group (IRR 1.5). A significantly lower IRR was seen in the Norwegian Forest Cat (IRR 0.38), the Maine Coon (IRR 0.48), the Persian/Exotic group (IRR 0.49) and the Cornish Rex (IRR 0.50). No common factor among the high-risk breeds explained their high risk for dystocia. There was no effect of location; that is, the incidence rate did not differ depending on whether the cat lived in an urban or rural area. Caesarean section was performed in 56% of the cats with dystocia, and the case fatality was 2%.Conclusions and relevance The incidence rate for dystocia was of a similar magnitude in purebred cats as in dogs. The IRR varied significantly among breeds, and the main cause for dystocia should be identified separately for each breed. A selection for easy parturitions in breeding programmes is suggested.
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| 3. |
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| 4. |
- Bergknut, Niklas, et al.
(author)
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Incidence of intervertebral disk degeneration-related diseases and associated mortality rates in dogs
- 2012
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In: Journal of the American Veterinary Medical Association. - : American Veterinary Medical Association (AVMA). - 0003-1488. ; 240, s. 1300-1309
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Journal article (peer-reviewed)abstract
- 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. (J Am Vet Med Assoc 2012;240:1300-1309)
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| 5. |
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| 6. |
- Byström, Anna, et al.
(author)
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Asymmetries of horses walking and trotting on treadmill with and without rider
- 2020
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In: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 53, s. 157-166
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Journal article (peer-reviewed)abstract
- Background Left-right movement symmetry is a highly desirable characteristic in sport horses.Objectives This study compared movement symmetry in well-trained dressage horses in unridden and unrestrained position and ridden in a dressage frame, and investigated possible associations between gaits.Study design Experimental study.Methods Seven sound, high-level dressage horses were measured at walk and sitting trot on a treadmill at several speeds under two conditions: with and without rider. Left-right differences in stance duration, stance protraction and retraction based on longitudinal hoof positions, ipsilateral limb tracking, minimum and maximum vertical positions of the dorsal spinous processes of the sixth thoracic (T6), third sacral vertebrae (S3) and wing of atlas, and vertical ground reaction forces were calculated and analysed in mixed models.Results At walk, five body variables indicated increased asymmetry in the ridden condition compared with unridden condition: forelimb stance duration (unridden/ridden left-right differences 9 vs 13 ms; P = .008), forelimb stance protraction (P = .004), stance retraction (P = .001) and first force peak (P = .003), and hindlimb stance retraction (P = .01). At trot, six body variables were more asymmetrical in the ridden condition: forelimb stance duration (2.5 vs 3.8 ms, P = .004); hindlimb stance protraction (P < .0001) and retraction (P = .01), T6 minimum (4 vs 6 mm, P = .001), T6 maximum (9 vs 11 mm, P = .01) and S3 maximum (6 vs 12 mm, P < .001). Five variables had significant associations between asymmetries at walk and trot, but only three demonstrated a positive slope.Main limitations A limited number of horses and riders were studied. Measurements were performed on a treadmill.Conclusions High-level horses moved slightly more asymmetrically when ridden in a dressage frame than in the unridden condition.
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| 7. |
- Byström, Anna, et al.
(author)
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Biomechanical findings in horses showing asymmetrical vertical excursions of the withers at walk
- 2018
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13
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Journal article (peer-reviewed)abstract
- The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic variables and vertical ground reaction forces (vGRFs). Seven dressage horses, judged clinically as being sound, walked unridden and unrestrained on a treadmill with an integrated force measuring system (480 Hz), from which spatiotemporal and vGRF variables were extracted. Markers were tracked by 12 infrared cameras (240 Hz). The vertical position of the sixth thoracic vertebra (T6), limb protraction and retraction distances throughout stance, and global limb lengths were determined. Contralateral trial-mean differences were calculated, including difference in T6 minimum vertical position between contralateral steps (T6minDiff). Mixed models were used to study associations between symmetry parameters. Trial-mean T6minDiff ranged between 0.3-23 mm. Of the seven horses, five consistently dropped the withers more in early left forelimb stance, one was fairly symmetrical, and one dropped the withers more in early right forelimb stance. Comparisons between contralateral limbs showed the following associations. The forelimb that was retracted when T6min was lowest showed greater retraction at toe-off (1 mm increase predicted 0.17 mm T6minDiff increase) and shorter stance duration (1 ms decrease predicted 0.3 mm T6minDiff increase). The hind limb that was in midstance when T6min was lowest showed a greater range of motion during the stance phase (1 mm increase in protraction or retraction predicted 0.2 mm T6minDiff increase). The haunches were displaced away from the side of the forelimb that was protracted when T6min was lowest (1 mm lateral shift predicted 0.07 mm T6minDiff increase). Forelimb and hind limb vGRF parameters were non-significant. Asymmetry of vertical withers movement in horses assessed as being sound at trot was related to a complex pattern of asymmetries in spatiotemporal variables throughout the stride cycle rather than to vertical load redistribution between the forelimbs. This suggests that the asymmetry may be due to inherent laterality rather than weight-bearing lameness.
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| 8. |
- Byström, Anna, et al.
(author)
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Differences in equine spinal kinematics between straight line and circle in trot
- 2021
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11
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Journal article (peer-reviewed)abstract
- Work on curved tracks, e.g. on circles, is commonplace within all forms of horse training. Horse movements in circles are naturally asymmetric, including the load distribution between inner and outer limbs. Within equestrian dressage the horse is expected to bend the back laterally to follow the circle, but this has never been studied scientifically. In the current study 12 horses were measured (optical motion capture, 100 Hz) trotting on left and right circles and on the straight without rider (soft surface). Data from markers placed along the spine indicated increased lateral bending to the inside (e.g. left bending on the left circle) of the thoracolumbar back (difference left circle vs. straight - 3.75 degrees; right circle+3.61 degrees) and the neck (left - 5.23 degrees; right+4.80 degrees vs. straight). Lateral bending ROM increased on the circle (+0.87 degrees and+0.62 degrees). Individual variation in straight-circle differences was evident, but each horse was generally consistent over multiple trials. Differences in back movements between circle and straight were generally small and may or may not be visible, but accompanying changes in muscle activity and limb movements may add to the visual impression.
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| 9. |
- Byström, Anna, et al.
(author)
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Guidelines for the Measurement of Rein Tension in Equestrian Sport
- 2021
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In: Animals. - : MDPI AG. - 2076-2615. ; 11
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Research review (peer-reviewed)abstract
- Simple Summary: The reins are used to control speed and direction of the horse's movement through the application of tension by the rider. When the rider holds the reins with a constant light contact, the mechanics of each gait is associated with a cyclic pattern of head and neck movements that is revealed in rein tension oscillations that have a typical shape and repetition frequency in each gait. The effects of the rider's aids, rider imbalance and extraneous movements of the horse's head and neck are superimposed on the basic patterns of the gaits. Rein tension is of interest to scientists and horsemen alike. Tension is relatively easy to measure but the equipment, analytic techniques and reporting of rein tension vary greatly. This paper makes recommendations to guide the selection of suitable equipment and appropriate methods for the collection, analysis and reporting of rein tension data. The goals are to describe correct procedures and common pitfalls in the collection, analysis and reporting of rein tension data that will facilitate comparisons between different studies.Rein tension is relatively easy to measure, and the resulting data are useful for evaluating the interaction between horse and rider. To date, there have been a number of studies using different transducers, calibration methods and analytical techniques. The purpose of this paper is to make recommendations regarding the collection, analysis and reporting of rein tension data. The goal is to assist users in selecting appropriate equipment, choosing verified methods of calibration, data collection and analysis, and reporting their results consistently to facilitate comparisons between different studies. Sensors should have a suitable range and resolution together with a fast enough dynamic response, according to the gait, speed and type of riding for which they will be used. An appropriate calibration procedure is necessary before each recording session. A recording frequency of 50 Hz is adequate for most rein tension studies. The data may be analyzed using time-series methods or by extracting and analyzing discrete variables chosen in accordance with the study objectives. Consistent reporting facilitates comparisons between studies.
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| 10. |
- Byström, Anna, et al.
(author)
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Influence of girth strap placement and panel flocking material on the saddle pressure pattern during riding of horses
- 2010
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In: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 42, s. 502-509
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Journal article (peer-reviewed)abstract
- Both flocking material and girthing have a significant influence on the saddle pressure and should thus be considered in saddle fitting. Wool seems a better flocking material than foam of the type used in the current study. For girthing, traditional placement seems equally good if not better than the v-system. However, further studies are needed to show if these results are valid for a larger population of riding horses.
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