Position of the Proximal Manica Flexoria under different grades of fetlock joint extension - A biomechanical observational study in the equine fore- and hindlimb

OBJECTIVE

 The aim of this study was to examine the position of the proximal manica flexoria and the proximal scutum under different grades of fetlock joint extension and to describe measurements and compare findings between equine fore- and hindlimbs.

STUDY DESIGN

 It was an observational study.

RESULTS

 During fetlock joint extension, the proximal manica flexoria and the proximal scutum displace distally relative to the palmar/plantar extent of the sagittal ridge of the cannon bone. The proximal manica flexoria is further displaced distal to the proximal scutum within the fetlock canal. No significant differences were identified between fore- and hindlimbs at different levels of fetlock joint extension. The proximal scutum was observed to be longer and thicker and the tendinous part of the manica flexoria was longer in forelimbs compared with hindlimbs.

CONCLUSION AND CLINICAL RELEVANCE

 The described findings contribute to the understanding of the pathogenesis of manica flexoria tearing. The fact that the proximal scutum and the tendinous part of the manica flexoria are shorter in the hindlimb might explain why the manica flexoria is more likely to get caught on the proximal aspect of the scutum and develop a tear in the equine hindlimb.

Findings consistent with equine proximal suspensory desmitis can be reliably detected using computed tomography and differ between affected horses and controls

The objective of this retrospective, observational, controlled study was to evaluate bone and soft tissue window CT images of the proximoplantar metatarsus III region in twenty horses with pain localized to the proximal suspensory ligament (PSL) and 20 horses with findings nonrelated to tarsal pain. All horses underwent CT and radiographic examination. Images were reviewed by three independent observers who graded the severity and localization of findings. Bone-related categories as well as soft tissue-related categories were evaluated. For the comparison of imaging findings in horses with and without proximal suspensory desmitis (PSD), mixed linear regression was performed. The intraclass correlation coefficient (ICC) was calculated to assess intraobserver agreement, and kappa statistics were employed to evaluate interobserver agreement. CT examination identified significantly more abnormalities in the diseased group. The scores for osseous exostosis (p = .015) and PSL enlargement (p = .004) were notably higher in PSD horses compared to controls. Intraobserver agreement was overall high (ICC .82-1.0), and interobserver agreement was substantial for the detection of mineralization (kappa = .61) and moderate for sclerosis (kappa = .43), exostosis (kappa = .43), and PSL enlargement (kappa = .48/.51). Measurements in the soft tissue window were significantly smaller than those in the bone window. Findings concurrent with PSD including osseous proliferation and sclerosis as well as soft tissue enlargement, mineralization, and avulsion can be reliably detected using CT. Findings from the current study supported the use of CT for evaluating horses with suspected PSD where high-field MRI is not available.

Modified toggle pin technique combined with prosthetic capsular reconstruction for surgical stabilization of coxofemoral luxation in a Shetland pony

OBJECTIVE

To describe open reduction and surgical stabilization of a coxofemoral luxation in a pony using a modified toggle pin technique and prosthetic joint capsule reconstruction without osteotomy of the greater trochanter.

ANIMAL

A 2-year-old Shetland pony with a bodyweight of 167 kg.

STUDY DESIGN

Case report.

METHODS

Radiographic examination confirmed craniodorsal luxation of the left coxofemoral joint. An open reduction with the aid of a pulley system was performed. A toggle pin was inserted through a bone tunnel extending from the level of the femoral shaft through the femoral head and the center of the acetabulum for the pin to be positioned on the medial wall of the acetabulum. FiberWire was subsequently passed through the cranial and caudal aspects of the acetabulum as well as a transverse tunnel in the femoral neck in a figure of 8 to facilitate capsular reconstruction. The pony was placed in a sling for 8 weeks and gradually returned to normal activity over 2 months.

RESULTS

Postoperative radiographic examination confirmed the position of the femoral head in the acetabulum with the implants in place. On 2-year follow-up the pony was sound at walk and trot.

CONCLUSION

A combined intra- and extra-articular stabilization technique for coxofemoral luxation in a pony resulted in successful long-term reduction and excellent outcome.

Diagnosis and outcome following tenoscopic surgery of the digital flexor tendon sheath in German sports and pleasure horses

BACKGROUND

Digital flexor tendon sheath (DFTS) pathology is an important cause of lameness in horses. The outcome after surgical treatment is variable and depends on the exact diagnosis.

OBJECTIVES

To (1) describe the prevalence of lesions associated with lameness caused by nonseptic DFTS tenosynovitis in a large population of German sports and pleasure horses; (2) determine the sensitivity and specificity of diagnostic imaging techniques for identifying lesions within the DFTS with tenoscopic diagnosis being the gold standard; (3) explore associations between tenoscopically diagnosed lesions and signalment, purpose, and limb affected; and (4) describe the outcome following DFTS tenoscopy with nonseptic DFTS tenosynovitis in this population.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of horses admitted for tenoscopic surgery of nonseptic DFTS tenosynovitis between 2011 and 2020 were reviewed. Follow-up information was obtained via telephone contact. Sensitivity and specificity of ultrasonography and contrast tenography were determined using tenoscopic diagnosis as gold standard and univariable analysis was used to explore associations between signalment, case history, and tenoscopic diagnosis.

RESULTS

Medical records from 131 horses were retrieved, of which 8 horses had bilateral disease and 6 horses were presented for tenoscopy on two separate occasions (3 for tenoscopy in the same limb, 3 in a different limb), thus, making a total of 145 limbs. Lesions were most commonly diagnosed in the deep (DDFT; n = 55 limbs) and superficial (SDFT; n = 55 limbs) digital flexor tendons. Manica flexoria (MF) lesions were detected in 44 limbs and palmar/plantar annular ligament (PAL) constriction in 99 limbs. In 36 limbs, only one structure within the DFTS was injured, whereas in 109 limbs a combination of lesions was noted, the most common being the combination of a SDFT lesion with PAL constriction. All affected limbs were examined with diagnostic ultrasonography; contrast tenography was performed in 86 limbs. For diagnosis of MF and DDFT tears, tenography was more sensitive (89% [confidence interval, CI: 65.4%-95.2%]; 72% [CI: 46.4%-89.3%], respectively) than specific (64% [CI: 52.5%-77.6%]; 53% [CI: 42.2%-73.3%], respectively) whereas ultrasonography was more specific (92% [CI: 84.5%-96.3%]; 92% [CI: 83.6%-96.0%]) with lower sensitivity (64% [CI: 47.7%-77.2%]; 54% [CI: 39.5%-67.9%]). For SDFT lesions, ultrasonography was highly specific (94% [CI: 86.9%-97.9%]) with lower sensitivity (66% [CI: 51.3%-77.4%]). Follow-up information following first surgery was obtained for 118 horses (132 limbs): 18 (15.3%) of 118 horses remained chronically lame, 40 (33.8%) performed at a reduced level and 60 (50.8%) performed at the same or higher level following rehabilitation after tenoscopy. Horses with DDFT lesions had the poorest outcomes with only 36.6% returning to the same or higher level of exercise.

MAIN LIMITATIONS

Retrospective analysis of clinical records and subjective outcome assessment based on owner follow-up with potential recall bias. Findings on diagnostic imaging are impacted by many factors including equipment quality and operator expertise and experience.

CONCLUSION

Diagnostic imaging techniques were complimentary and contrast tenography was sensitive and ultrasonography was specific for the diagnosis of MF and DDFT lesions. Following tenoscopic surgery for nonseptic tenosynovitis of the DFTS, approximately half the cases were able to return to preinjury level of exercise.

Other Clinical Problems of the Equine Foot

Many disorders affect the equine foot, and many hoof problems have multiple predisposing causes. Surgery may be necessary after conservative management has failed. Diseases of the hoof capsule may seem simple, but their effect on performance can be long-lasting and healing is often prolonged. Diagnosis of problems within the hoof capsule is enhanced with the use of computed tomography and MRI. The prognosis of fractures has improved with strategic placement of lag screws across fracture planes using aiming devices and advanced intraoperative imaging techniques. Collaboration between the clinician and a skilled farrier is important for successful management of hoof disorders.

Single-cut osteotomy for correction of a complex multiplanar deformity of the radius in a Shetland pony foal

OBJECTIVE

To describe the surgical correction of a multiplanar deformity of the radius in a pony using a single-cut osteotomy.

STUDY DESIGN

Case report.

ANIMALS

A 9-week-old male Shetland pony foal with a bodyweight of 47 kg.

METHODS

The foal presented with a complex multiplanar deformity of the right radius. A 3-dimensional model of the bone was created based on computed tomography (CT) imaging. To correct the deformity, the cutting plane for a single-cut osteotomy was calculated following the mathematical approach described by Sangeorzan et al. After osteotomy, the bone was realigned and stabilized with two 4.5 locking compression plates (LCPs).

RESULTS

Recovery from surgery was uneventful, and the foal remained comfortable. A CT exam 15 weeks after surgery revealed that diaphyseal deformities improved substantially in procurvatum (from 8° to 1°), varus (from 27° to 0°), and rotation (30° to 5°). The operated radius was 2.1 cm shorter than the left. Eighteen-month follow up confirmed a functionally and cosmetically acceptable outcome.

CONCLUSION

The single-cut osteotomy resulted in the successful correction of a multiplanar equine long-bone deformity with a favorable outcome in a Shetland pony.

CLINICAL SIGNIFICANCE

Single-cut osteotomy is an alternative surgical technique for the correction of complex diaphyseal long-bone equine deformities. Computed tomography data and the possibility of printing 3D models provides a significant advantage for rehearsing the procedure and for evaluating the correction that was achieved.

A retrospective multicenter study on the use of locking compression plates for scapulohumeral arthrodesis in small equids

OBJECTIVE

To report on technical aspects and outcomes after scapulohumeral arthrodesis (SHA) with a locking compression plate (LCP) in small equids.

STUDY DESIGN

Retrospective multicenter case series.

ANIMALS

Client-owned Shetland Ponies, Miniature Shetlands, and American Miniature Horses (n = 15).

METHODS

Inclusion criteria were completed SHA with an LCP to treat scapulohumeral osteoarthritis/subluxation and availability of postoperative radiographs. Contributing surgeons completed a questionnaire to collect data. All radiographs were reviewed for this study. Follow-up information was obtained via re-admission to the hospital or telephone interview of the referring veterinarian or owner. Outcome was subjectively scored as excellent, good, moderate, or poor based on lameness and function.

RESULTS

Sixteen SHAs were performed in 15 equids (body weight 65-145 kg) by nine different surgeons. A narrow 4.5/5.0 mm LCP (7-16 holes) was used in 14 of the 16 SHAs. Follow-up was collected 2.5 years after surgery (median; range: 9 weeks to 10 years). Major complications related to the SHAs were noted in 4 of the 13 horses alive long term, consisting of implant failure (n = 1), surgical site infection (n = 2), and scapular fracture (n = 1). The outcome was graded as excellent in 4, good in 5, and moderate in 4 horses. Two ponies were euthanized because scapulohumeral osteoarthritis and subluxation developed in the contralateral limb.

CONCLUSION

Although major complications occurred in about one-third of ponies, SHA with LCP led to long-term survival with good function in most ponies.

CLINICAL SIGNIFICANCE

SHA with an LCP offers a high chance for good long-term outcome in small equids although contralateral disease may affect outcome.

Ex vivo evaluation of an alternative technique for resection of the proximal manica flexoria in horses

OBJECTIVE

To describe and evaluate an alternative technique for tenoscopic resection of the manica flexoria (MF).

STUDY DESIGN

Descriptive study.

SAMPLE POPULATION

Equine cadaver forelimbs and hind limbs (n = 36).

METHODS

Three surgeons varying in experience resected the MF in 12 limbs. The procedure was divided into six steps, including resection of the lateral/medial borders of the MF with a hook knife and resection of the proximal border with a micro scalpel. Outcomes compared between surgeons included completeness of resection, appearance of the margins of resection, appearance of the resected MF, collateral damage, and time required for resection.

RESULTS

The MF was successfully resected in all specimens, with a median time of 14 minutes 54 seconds (range, 6 minutes 42 seconds to 43 minutes 33 seconds). Nineteen of 36 MF were categorized as symmetric, 11 of 36 MF were categorized as mildly asymmetrical, and six of 36 MF had unequal borders. No differences were detected between surgeons regarding the appearance of the MF and number of iatrogenic lesions. Five lesions were considered potentially clinically relevant; three were caused by the arthroscope in the scutum (1) and the deep digital flexor tendon (DDFT; 2), and two consisted of DDFT damage caused by the microscalpel.

CONCLUSION

The MF was successfully and symmetrically resected with minimal damage to adjacent structures by surgeons with varying levels of experience.

CLINICAL SIGNIFICANCE

The results of this study provide evidence to justify further evaluation of the technique described here in live horses with rupture of the MF.

Long term outcome after surgical correction of mandibular brachygnathia with unilateral type 1 external skeletal fixation

OBJECTIVE

To describe complications and long-term outcome after surgical correction of severe overbite in 7 horses using corrective osteotomy and a Type I external fixator.

STUDY DESIGN

Case series.

ANIMALS

Horses (n = 7).

METHODS

Seven horses with severe mandibular brachygnathia were treated by corrective osteotomy and a Type I external fixator. Data on surgical technique, complications, long-term outcome and owner satisfaction were recorded.

RESULTS

Severe mandibular brachygnathia was corrected successfully in all horses. Short term follow-up revealed a relatively high morbidity due to several complications such as surgical site infection, sequestrum formation and instability due to early pin loosening. Long-term over all owner satisfaction was very high.

CONCLUSIONS

Corrective osteotomy and fixation with an external fixator is an effective surgical technique for correction of severe mandibular brachygnathia and offers good results in a long-term perspective.

Treatment of chronic proximal suspensory desmitis in horses using focused electrohydraulic shockwave therapy

The objective of the present clinical report was to investigate the short- and long-term outcomes of chronic proximal suspensory desmitis (PSD) treated with Extracorporeal Shockwave Treatment (ESWT). Fifty-two horses with chronic PSD in the forelimb (34 cases) or hindlimb (22 cases) were included in the study. Three horses had lesions in both hindlimbs and one in both forelimbs. The origin of the suspensory ligament was treated every three weeks for a total of three treatments using 2000 impulses applied by a focused ESWT device (Equitron) at an energy flux density of 0.15 mJ/ mm2. This treatment regime was followed by box rest and a controlled exercise program of 12 weeks duration. The horses were assessed 3, 6, 12, 24 weeks and one year after the first treatment. Of the 34 cases with forelimb PSD, 21 (61.8%) had returned to full work by six months after diagnosis and 19 cases (55.9%) were still in full work one year after ESWT. Of the 22 horses with hindlimb PSD, 9 (40.9%) had returned to full work by six months and 4 (18.2%) were still in full work one year after diagnosis. There was no association (chi-square test) between the outcome and the severity of the initial ultrasonographic and/or radiographic findings. Compared with the results of other clinical studies, these findings suggest that in horses with PSD of fore- and hindlimb, the prognosis for returning to full work six months after diagnosis can be improved when ESWT and a controlled exercise program are used. However, a high rate of recurrence occurred in the hindlimb despite treatment.

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.

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 > or = 0.90 while those for the combined IAc + IAn processes were > or = 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 > or = 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.

Magnetic resonance imaging, ultrasonography and histology of the suspensory ligament origin: a comparative study of normal anatomy of warmblood horses

REASONS FOR PERFORMING STUDY

The diagnosis of lameness caused by proximal metacarpal and metatarsal pain can be challenging. Magnetic resonance imaging (MRI) offers the possibility for further diagnosis but there have been no studies on the normal MRI appearance of the origin of the suspensory ligament (OSL) in conjunction with ultrasonography and histology.

OBJECTIVES

To describe the MRI appearance of the OSL in fore- and hindlimbs of sound horses and compare it to the ultrasonographic and histological appearance. The findings can be used as reference values to recognise pathology in the OSL.

METHODS

The OSL in the fore- and hindlimbs of 6 sound horses was examined by ultrasonography prior to death, and MRI and histology post mortem. Qualitative evaluation and morphometry of the OSL were performed and results of all modalities compared.

RESULTS

Muscular tissue, artefacts, variable SL size and shape complicated ultrasonographic interpretation. In MRI and histology the forelimb OSL consisted of 2 portions, the lateral being significantly thicker than medial. The hindlimb SL had a single large area of origin. In fore- and hindlimbs, the amount of muscular tissue was significantly larger laterally than medially. Overall SL measurements using MRI were significantly higher than using histology and ultrasonography and histological higher than ultrasonographic measurements. Morphologically, there was a good correlation between MRI and histology.

CONCLUSIONS

MRI provides more detailed information than ultrasonography regarding muscle fibre detection and OSL dimension and correlates morphologically well with histology. Therefore, ultrasonographic results should be regarded with caution.

POTENTIAL RELEVANCE

MRI may be a diagnostic aid when other modalities fail to identify clearly the cause of proximal metacarpal and metatarsal pain; and may improve selection of adequate therapy and prognosis for injuries in this region.

Assessment of scintigraphic and thermographic changes after focused extracorporeal shock wave therapy on the origin of the suspensory ligament and the fourth metatarsal bone in horses without lameness

OBJECTIVE

To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography.

ANIMALS

6 warmblood horses without lameness.

PROCEDURE

The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused ESWT, nuclear scintigraphy was performed on days -1, 3, 16 (before second ESWT), and 19. Thermography was performed on days -1, 0 (1 hour after first ESWT), 1, 3, 8, 16 (twice; before and 1 hour after second ESWT), and 19. On days 3, 16 (first scans), and 19, thermography was performed before scintigraphy.

RESULTS

Scintigraphically, significant variations in radiopharmaceutical activity at the OSL-MC were detected in treatment and control limbs. No significant differences, however, in mean temperature or radiopharmaceutical activity could be detected by use of thermography or nuclear scintigraphy, respectively, between the treatment and control limbs at any time point in response to ESWT.

CONCLUSIONS AND CLINICAL RELEVANCE

After 2 treatments of focused ESWT, no physiologic effect on the studied structures could be demonstrated by use of nuclear scintigraphy or thermography. Results of this study indicate that at currently used ESWT settings, no damage to the bone or bone-tendon junction should occur.

Histomorphologic evaluation of extracorporeal shock wave therapy of the fourth metatarsal bone and the origin of the suspensory ligament in horses without lameness

OBJECTIVE

To determine via histologic examination and scintigraphy the effect of focused extracorporeal shock wave therapy (ESWT) on normal bone and the bone-ligament interface in horses.

ANIMALS

6 horses without lameness.

PROCEDURE

Origins of the suspensory ligament at the metacarpus (35-mm probe depth) and fourth metatarsal bone (5-mm probe depth) were treated twice (days 0 and 16) with 2,000 shocks (energy flux density, 0.15 mJ/mm2). One forelimb and 1 hind limb were randomly treated, and the contralateral limbs served as nontreated controls. Bone scans were performed on days -1 (before ESWT), 3, 16, and 19. Histomorphologic studies of control and treated tissues were performed on day 30.

RESULTS

ESWT significantly increased the number of osteoblasts but caused no damage to associated soft tissue structures and did not induce cortical microfractures. A significant correlation between osteoblast numbers and radiopharmaceutical uptake was noticed on lateral views of the hind limb on days 3 and 16 and on caudal views of the forelimb on day 3.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that ESWT has the potential to increase osteoblast numbers in horses. The correlation between increased osteoblast numbers and radio-pharmaceutical uptake 3 days and 16 days after the first ESWT suggested that stimulation of osteogenesis occurred soon after ESWT. No damage to bone or the bone-ligament interface should occur at the settings used in this study, and ESWT can therefore be administered safely in horses.

Evaluation of skin sensitivity after shock wave treatment in horses

OBJECTIVE

To evaluate the effects of shock wave treatment on cutaneous nerve function, compared with the effects of local nerve block and sedation.

ANIMALS

18 clinically sound Swiss Warmbloods.

PROCEDURE

Horses were randomly allocated to 3 groups and received different amounts and types of shock waves (extracorporeal shock wave treatment [ESWT] or radial pressure wave treatment [RPWT]). Horses were sedated with xylazine and levomethadone. Shock waves were applied to the lateral palmar digital nerve at the level of the proximal sesamoid bones on 1 forelimb. Skin sensitivity was evaluated by means of an electrical stimulus at the coronary band before and 5 minutes after sedation and at 4, 24, and 48 hours after application of ESWT or RPWT. On the contralateral forelimb, skin sensitivity was tested before and 10 minutes after an abaxial sesamoid nerve block.

RESULTS

No significant changes in skin sensitivity were detected, regardless of the shock wave protocol applied. Mean reaction thresholds after sedation were more than twice the baseline thresholds. After the abaxial sesamoid block, no reaction was recorded in any of the horses.

CONCLUSIONS AND CLINICAL RELEVANCE

Application of ESWT or RPWT to the palmar digital nerve had no effect on cutaneous sensation distal to the treated region for at least 2 days after application. The analgesic effect of sedation on reaction to electrical stimuli was distinct but varied among horses.

[Healing process of uncomplicated sole ulcers in dairy cows kept in tie stalls: clinical description and blood chemical investigations]

A total of 74 dairy cows with 105 separate lesions were treated and the healing process was observed for half a year and the results compared with the biochemical data. The mean time for the formation of a closed layer of horn was 25 days for lesions with slight corium alterations, 33 days for moderate and 42 days for severe alterations. Thirty days after the initial treatment 68% of all lesions were completely covered by a solid layer of new horn. The further evaluation of the healing process was based on quality and rate of the new horn formation, recovery from lameness and sensitivity to hooftesters. Using these parameters the healing potential of exposed corium was judged one month after treatment with a scoring system. The 30-day-healing process was considered to be good in 61% and moderate to bad in 39% of the cows. The concentration of glucose, cholesterin, LDH and blood urea was increased in one third of the animals. Phosphorus and magnesium concentrations were lower than the reference values in 30%, and 26% of the animals, respectively. Cows with prolonged healing had higher levels of bilirubin, creatinkinase, LDH, ALT and AST than cows with a good healing process. Concentration of iron, vitamin A and biotin were significantly lower in cows with moderate to bad healing parameters than cows with a good healing potential. From these results it is suggested that biochemical blood parameters and the vitamin status might influence the healing of uncomplicated sole ulcers, respectively.

[Bovine sole ulcer: a literature review]

Sole ulcers are the most frequently encountered lesion in lame cattle. They are of growing concern to the dairy industry since the incidence of ulcers is increasing. Ulcers cause financial losses, the animal's wellbeing is disturbed to a high degree and they harm the image of the industry in general. Biomechanic factors and laminitis are of particular significance in the pathogenesis of the sole ulcer. The development of sole contusions and ulcers is assumed to occur in 3 phases (Sinking theory). In the first phase there is a general disturbance in the vascular system of the corium. The second phase follows when the structures that suspend the claw bone within the horn shoe give way. The locus minoris resistentiae has yet to be identified. The claw bone sinks and causes various lesions when it pinches the underlying sole or heel corium. The third phase begins when haemorrhages become visible on the horn surface of the sole or when the sole ulcerates; socalled third phase lesions. The relationship between the development of sole ulcers and anatomical structures such as the claw bone's tuberculum flexorium or the fat bodies under the bone are unclear. Epidemiological studies have shown that sole ulcers have a high rate of recurrence. The healing processes and the factors that influence them have hitherto not been studied.

[Healing process of claw lesions in dairy cows in alpine mountain pastures]

The field study investigated severity, localisation and incidence of claw lesions of dairy cows and their healing process during a period of three months on selected mountain pastures in the central part of Switzerland. In 60 cows, which were at least 120 days in their lactation, the healing process was compared with the biochemical profiles. In 141 cows 197 claw lesions were recorded. Diagnosed were only sole ulcers (38%) and white line lesions (62%). In the first and second half of the summer term, the number of claw lesions was equal, although more severe lesions occurred mainly during the second half (89%). The lesions were treated surgically and the affected claw was elevated on a wood block or a plastic shoe. Average time for formation of a close layer of horn was 14 days. A delayed healing process was observed in dairy cows with an milk yield over 5500 kg per lactation, as well as in the second half of the summer term. Cows with a delayed healing process had significantly higher concentrations of free fatty acids and beta-hydroxybutyrate, and higher plasma enzyme activities for AST than cows with adequate healing process. This indicates that cows with a relatively high milk production touch upon the limits of their physical capacity under harder conditions on alpine pastures, which may affect also the healing process of claw lesions.

Long-term results of bovine mandibular fractures involving the molar teeth

OBJECTIVE

To evaluate postoperative complications and long-term outcome of simple mandibular fractures involving the molar teeth in cattle.

ANIMAL POPULATION

Seventeen cattle with mandibular fractures involving the molar teeth with disruption of the occlusal surface.

METHODS

Treatment consisted of application of AO/ASIF-Pinless External Fixators (Synthes, Paoli, PA) in 14 cows, interdental wire stabilization in 1 cow, and conservative treatment in 2 cows. Long-term outcome was determined by telephone contact with the owners, and whenever possible, cows were reevaluated by physical, intraoral, and radiographic examination of the fracture site.

RESULTS

Loosening of the fixation device (4 cattle) and bone sequestration (11 cattle) were the most commonly encountered complications. Oral incontinence during rumination was a minor complication in 1 cow. The mean (+/- SD) time the cattle were in production was 26 (+/- 14) months, with 10 cows still alive at follow-up examination; 9 cows were reevaluated. On intraoral examination there was a step in the occlusal surface at the level of the healed fracture site in 3 cows, wave and shear mouth formation in 3 cows, and enamel point formation in 1 cow. Radiographically, all the reevaluated fractures had healed, and there were no signs of tooth root infection.

CONCLUSIONS

Complications during healing were bone sequestration and loosening of the fixator. None of the cows was removed from production because of fracture-associated complications, but decreased milk yield occurred in 2 cows. Tooth abnormalities developed in 6 cows, but function of the mandible was not altered.

CLINICAL RELEVANCE

Mandible fractures involving the molar teeth carry a good prognosis for return to normal function. Radiographic follow-up is necessary to detect bone sequestration.

Diagnosis of Lyme disease in two cows by the detection of Borrelia burgdorferi DNA

Two cows from different herds in a district of Switzerland known to harbour ixodid ticks had erythematous lesions on the hairless skin of the udder, were in poor general condition with a poor appetite and decreased milk production, and had a stiff gait and swollen joints. Borrelia burgdorferi sensu strictu DNA was detected in samples of synovial fluid and milk from one of the cows and Borrelia afzelii DNA was detected in synovial fluid from the other by means of a real-time PCR.

Concentration of volatile fatty acids in digesta samples obtained from healthy cows and cows with cecal dilatation or dislocation

OBJECTIVE

To compare concentrations of acetic, propionic, butyric, and i- and n-valerianic acids in digesta samples obtained from the rumen, cecum, proximal loop of the ascending colon (PLAC), and rectum of healthy cows and cows with cecal dilatation or dislocation (CDD).

ANIMALS

20 cows with CDD and 20 healthy cows.

PROCEDURE

Samples were collected from all sites during surgical correction of CDD and also from the rectum 1, 2, and 3 days after surgery (group CDD). Samples from healthy (control) cows, matched on the basis of diet and milk yield, were obtained at a slaughterhouse. Concentrations of volatile fatty acids (VFA) were analyzed by use of gas chromatography. Absolute concentration of each VFA was additionally corrected for pH to allow calculation of the concentration of undissociated VFA.

RESULTS

Absolute concentration and concentration of the undissociated form of all analyzed VFA were significantly increased in samples collected from the cecum and PLAC of cows in group CDD, compared with concentrations for control cows. Within 3 days after surgery, significant decreases of the absolute concentration of butyric, i- and n-valerianic acids, and undissociated i- and n-valerianic acids were evident in samples obtained from the rectum of group-CDD cows. Concentrations of VFA in samples obtained from the rectum during surgery correlated with corresponding VFA concentrations in samples obtained from the PLAC.

CONCLUSIONS

Concentrations of VFA are increased in the cecum and PLAC of cows with CDD. However, the role of increased concentrations of VFA in the etiopathogenesis of CDD is unknown.

Stabilisation of a mandibular fracture in a cow by means of a pinless external fixator

A four months pregnant, four-year-old Brown Swiss cow with mandibular fractures of the right horizontal ramus and the symphysis was treated surgically with a new pinless external fixator. Healing was complicated by the sequestration of bone at the fracture site. After the sequestrum had been removed a radiographic examination revealed that the fracture had healed completely.

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.

Ultrasonographic diagnosis of urachal cyst in three calves

In 3 calves with irreducible umbilical swelling attributable to urachal cyst, ultrasonography was helpful in establishing a definitive diagnosis. After surgical resection of the persistent urachus, 2 calves recovered without complications. In 1 calf in which the urachus had ruptured subcutaneously during forceful diagnostic palpation, additional surgical debridement of severe skin necrosis, caused by subcutaneous accumulation of urine in the umbilical region, was required. Most irreducible masses of the umbilical area of calves can be classified as attributable to infection, hematoma, or incarcerated umbilical hernia. Urachal cyst should always be considered in the differential diagnosis of an irreducible umbilical mass. Careful palpation of the umbilicus is indicated to avoid the potential complication of iatrogenic rupture of a urachal cyst.

Marsupialization of umbilical vein abscesses with involvement of the liver in 13 calves

Omphalophlebitis with liver involvement was diagnosed by ultrasonography in 13 calves. In the initial surgical procedure, the infected umbilical vein was marsupialized by cranial translocation in a median celiotomy and was flushed daily until healing occurred. In a second surgical procedure, the contracted umbilical vein was removed. Nine calves were clinically healthy after treatment. One had reformation of two abscesses because of inadequate post-surgical treatment. One calf was euthanatized because of an intussusception of the small intestine, and two calves had adverse reactions and developed septic shock when some of the lavage fluid, which was applied under pressure, entered the systemic circulation. It was concluded that umbilical vein abscesses should not be flushed under pressure in calves younger than 2 months of age. The principal advantages of cranial translocation of the umbilical vein in a median celiotomy are that only one abdominal incision is required and that the infected umbilical vein tissue does not have to be passed intraabdominally to a paramedian position.