Diagnostic accuracy of digital photography and image analysis for the measurement of foot conformation in the horse

Reasons for performing study: Rigorous evaluation of practicable methods for the objective assessment of foot conformation has not been performed. Objectives: To assess the practicability, precision and accuracy of the process of obtaining measurements of horses' feet using photography and image processing software. Methods: Precision study: Lateral photographs of horses' feet were obtained twice by 2 veterinary surgeons (image acquisition ‐ IAc). Photographs were analysed by 2 masked veterinary surgeons on 2 occasions (image analysis ‐ IAn). Measurements were compared within and between operators for self and non‐self acquired photographs. Agreement indices (AIs) and 95% limits of agreement (LOA) were calculated for the IAn process alone and for the combined IAc + IAn processes. Accuracy study: Measurements obtained from lateral photographs were compared with those obtained from lateromedial radiographs. AIs and 95% LOA were calculated for each measurement. Results: Precision study: Mean intra‐ and interoperator AIs for the IAn process alone were ≥0.90 while those for the combined IAc + IAn processes were ≥0.89 for all measurements. Similar mean AIs and 95% LOA were calculated regardless of image origin. The 95% LOA for hoof angle, heel height/toe height% and coronary band angle for all comparisons were within target values. Accuracy study: Mean AIs were ≥0.89 for all measurements. The 95% LOA for heel height/toe height% and coronary band angle were within target values. Conclusions: Excellent precision was identified within and between operators regardless of image origin. High levels of accuracy were also identified, especially for heel height/toe height% and coronary band angle, indicating that photography and radiography may be used interchangeably. Potential relevance: Acquisition and analysis of photographic images is an appropriate method for the objective measurement of foot conformation, both in clinical and research settings.     

Surgical management of complete diaphyseal third metacarpal and metatarsal bone fractures: Clinical outcome in 10 mature horses and 11 foals

Reasons for performing study: Osteosynthesis of third metacarpal (McIII) and third metatarsal (MtIII) bone fractures in horses is a surgical challenge and complications surrounding the repair are common. Retrospective studies evaluating surgical repair, complications and outcome are necessary to increase knowledge and improve success of long bone fracture repair in the horse. Objectives: To evaluate clinical findings, surgical repair, post operative complications and outcome of 10 mature horses and 11 foals with McIII or MtIII fractures that were treated with open reduction and internal fixation (ORIF). Methods: Medical records were reviewed and follow‐up information obtained by means of radiographs and/or telephone questionnaire. Results: Survival was achieved in 62% of the horses (3 mature/10 foals). On long‐term evaluation (>6 months) 11 horses (2 mature/9 foals) were fit for their intended activity, one mature horse had a chronic low grade lameness, and one foal was lost to follow‐up because it was sold. The main fracture types were simple transverse (33.3%) or simple oblique (28.6%) and 71.4% of the fractures were open, 3 Type I (one mature/2 foals) and 12 type II (7 mature/5 foals). The preoperative assessment revealed inadequate emergency treatment in 10 horses (5 mature/5 foals; 47.6%). Survival rate of horses with open fractures was 12.5% (1/8) in mature and 85.7% (6/7) in foals. Post operative incisional infection (4 mature, 3 foals) was only managed successfully in 2 foals. Fracture instability related to inadequate fracture fixation technique occurred in 4 horses (all mature) and was always associated with unsuccessful outcome. Conclusions: Age, bodyweight and infection are strongly associated with outcome in treatment of complete McIII/MtIII fractures. Clinical relevance: Rigid fixation using plates and screws can be successful in treatment of closed or open, complete diaphyseal McIII/MtIII fractures in mature horses and foals. Instable fixation, infection and a bodyweight >320 kg are major risk factors for unsuccessful outcome.     

Ventral Locking Compression Plate for Treatment of Cervical Stenotic Myelopathy in a 3-Month-Old Warmblood Foal

Objective— To report a novel technique for cervical vertebral fusion in a foal with cervical vertebral malformation (CVM).
Study Design— Case report.
Methods— A 3-month-old Warmblood filly with ataxia, weakness, and stenotic myelopathy at the level of the articulation of the 6th (C6) and 7th (C7) cervical vertebrae had a 7-hole broad locking compression plate (LCP) applied to the ventral aspect of C6 and C7 using seven 5.0-mm locking screws. Revision surgery was required to replace the self-drilling screws, which had migrated, with longer non self-drilling screws. Fusion and growth of the vertebrae were monitored radiographically at 4, 10, and 16 months using radiography and the filly was followed for 32 months.
Results— The filly recovered well from the surgical procedures and by 30 months had improved by 2.5 neurologic grades. Ventral inter-central joint fusion was evident by 10 months. Continued vertebral growth occurred in all but the cranial physis of the C7 vertebral body.
Conclusions— A ventrally placed LCP provided adequate support for fusion and stability of cervical vertebrae.
Clinical Relevance— Use of an LCP applied ventrally offers an alternative to basket use in small or immature horses for fusion of cervical vertebrae.     

Pinless External Fixation of Mandible Fractures in Cattle

Objective — This report describes our experience with a new technique for stabilization of mandibular fractures in cattle using a pinless external fixator.
Study Design — Mandibular fractures were stabilized with a pinless external fixator, which is a modification of a unilateral AO/ASIF (Association for the Study of Internal Fixation)-fixator in which pins are replaced with bone clamps.
Animals — Seven dairy cattle between 1 and 5 years of age.
Methods — Fracture stabilization was achieved by using the pinless external fixator. Postoperative management included intravenous administration of sodium chloride-glucose and antibiotics. A suspension of ruminal contents from a normal cow together with linseed and grass pellets was administered with a gastric tube.
Results — Three to 10 days after surgery six of seven cows masticated comfortably. The only failure was a yearling with a 10-day-old open infected fracture. This animal was slaughtered 9 days after surgery because of additional problems. In six cases there was enough callus formation 33 to 54 days after surgery to stabilize the fracture. The fixation devices were removed under heavy sedation. The major complication was bone sequestration at the fracture site, which required additional treatment.
Conclusion — The pinless fixator has proven satisfactory for external stabilization of unilateral horizontal ramus fractures of the mandible in cattle.
Clinical Relevance — The technique provides good stability without penetration of the medullary cavity and damage to the tooth roots. Other advantages of the technique include ease of application, minimal surgical trauma, and the short surgical time for application.     

The proximal aspect of the suspensory ligament in the horse: How precise are ultrasonographic measurements?

Reasons for performing study: To evaluate intra‐ and interobserver variability in ultrasonographic measurements of the proximal aspect of the suspensory ligament (PSL) in the horse. Hypothesis: A minimum difference of ≥20% is required to differentiate reliably between physiological and pathological alterations related to dimensions. Materials and methods: Two operators examined the PSL in all 4 limbs of 14 horses twice using different techniques and different probes with and without standoff pads. Measurements were taken from the longitudinal and transverse images. Inter‐ and intraoperator variability was evaluated using agreement indices (AI) and the 95% limits of agreement (LOA). Results: On the longitudinal scan the mean inter‐ and intraoperator AIs for dorsopalmar/‐plantar thickness were both ≥0.89 and the 95% LOA were within target values for almost all intra‐ and interoperator comparisons. Similar mean AIs and 95% LOA were calculated for the dorsopalmar/‐plantar thickness on the transverse image. For lateromedial width, cross‐sectional area and circumference on the transverse scan, the mean inter‐ and intraoperator AIs ranged between 0.81 and 0.95 and the 95% LOA were higher than target values regardless of the imaging technique used. In general, better values for AIs and 95% LOA were achieved in the fore‐ compared with the hindlimb. Conclusion and clinical relevance: Acceptable precision was identified within and between operators only for the dorsopalmar/‐plantar thickness in longitudinal and in transverse scanning directions. For the lateromedial width, cross‐sectional area and circumference, a relatively large variability was identified. This aspect has to be considered if these parameters are to be used for objective measurement of the PSL from the transverse ultrasound image.     

An investigation of the relationship between race performance and superficial digital flexor tendonitis in the Thoroughbred racehorse

Reasons for performing study: There is limited information regarding the number of races and the period for evaluation of outcome which is critical for assessment of SDF tendonitis treatments. Objective: To evaluate the re‐injury rate and racing performance of Thoroughbred racehorses that sustain SDF tendonitis in relation to matched controls in terms of number of races post treatment and maximum racing performance ratings before and after injury. Study design: Clinical records and racing histories of 401 racehorses with a first occurrence of SDF tendonitis diagnosed by ultrasonography. Controls were of the same age, sex and were horses training in the same establishment at the time of injury as the case horses and where the trainer reported that the horse had not had a previous SDF tendon injury or treatment. Results: Eighty percent of both case and control horses returned to racing after the date of injury, and the re‐injury proportion within 3 years of treatment was 53%. The difference in Racing Post Rating_(max) (RPR_(max)) and the Racing Post Rating in the race immediately before the treatment date was significantly smaller in case horses (mean = 9.6 lbs; range = 0–75) compared to control horses (mean = 17.0 lbs; range = 0–79). No significant decrease in RPR_(max) was noted post injury. No difference between case and control horses was found for return to racing and racing 3 times, but control horses were significantly more likely to compete 5 races post treatment date than case horses. Conclusion and clinical relevance: Injury was associated with an individual's pre‐injury maximum performance level and return to racing and completion of 3 races are not useful indicator of the outcome of horses with SDF tendonitis. The assessment of the outcome of horses with an SDF injury in a population of racehorses using the number of races post injury requires a minimum of 5 races post injury to be a useful indicator. Further, a re‐injury proportion in a population of horses in training for 3 years post treatment.     

Preliminary experiments on utilization of water hyacinth by grass carp

Preliminary aquarium experiments have been carried out on the feeding of water hyacinth (Eichhornia crassipes (Mart.) Solms) to grass carp (Ctenopharyngodon idella Via.). Eleven months old fish weighing 38 to 104 g were fed for 50 days exclusively on E. crassipes. Roots and leaves were accepted readily but the swollen petioles reluctantly. The fish developed well, producing 6.5g live weight from 10g dry matter of E. crassipes. The results suggest the possible use of grass carp for the solution of E. crassipes problems. Further extensive experiments are required in the field, however, to determine the influence of grass carp on the ecology of waters infested with this weed.     

Weed composition and cover after three years of soil fertility management in the central Brazilian Amazon: Compost, fertilizer, manure and charcoal applications

Soils of the lowland tropics in the central Brazilian Amazon are generally highly leached, acidic and nutrient-poor. Charcoal, combined with other soil amendments, might improve fertility but this, in turn, could lead to increased weed problems for agricultural production. This experiment was conducted to assess weed pressure and species composition on plots receiving various inorganic and organic soil amendments, including charcoal. Additions of inorganic fertilizer, compost and chicken manure resulted in increases in weed ground cover of 40, 22 and 53%, respectively, and increases in species richness of 20, 48, and 63%, respectively. When chicken manure was applied, dominance by a few weed species was reduced, such that different species were more evenly represented. Although charcoal additions alone did not significantly affect weed ground cover or species richness, a synergistic effect occurred when both charcoal and inorganic fertilizers were applied. The percentage ground cover of weeds was 45% within plots receiving inorganic fertilizer, 2% within plots receiving charcoal and 66% within plots receiving both amendments. Improvements in the fertility of nutrient-poor soils of the tropics might increase weed pressure and make the development of effective weed management strategies more critical. These effects on weed populations were observed nearly 2.5 years after the addition of charcoal, chicken manure and compost, and > 1 year after the last application of inorganic fertilizer.     

基于遥感的景观格局时空动态研究

基于试验区域1990年TM影像和2002年ETM+影像,采用遥感和地理信息系统相结合的技术方法,应用景观分析软件Fragstats3.3,对试验区域12 a来景观变化进行了动态研究。结果表明:12 a间,试验区域景观发生巨大变化。(1)1990～2002年间,森林面积大幅度减少,其他植被、裸地、建设用地、水域面积得到了增加,其中建设用地相对自身增幅最大,年平均增长率为20.9%。(2)两时期的景观基质均为森林,其他植被、裸地、建设用地、水域作为斑块单元镶嵌其中,5种景观类型相互之间转化频繁,森林主要转化为其他植被和裸地;同时其他植被、裸地也有大部分转化为森林,其原因是人工林的建立,转化后的景观森林的主导优势已不明显。(3)总体景观的破碎度呈增加趋势,但不同景观类型的破碎化指数的变化则表现不同,森林和水域表现出下降趋势,而其他植被、裸地、建设用地的景观破碎化指数则呈上升趋势,景观向无序状态发展。