Effect of sedation on fore- and hindlimb lameness evaluation using body-mounted inertial sensors.

REASONS FOR PERFORMING STUDY: Diagnostic analgesia is an integral part of equine lameness examinations, but is challenging to perform in uncooperative horses. Using sedation to facilitate this might, because of analgesic and ataxia-inducing effects, interfere with lameness evaluation. OBJECTIVES: To evaluate whether sedation with low-dose xylazine would alter lameness amplitude as measured by body-mounted inertial sensors. STUDY DESIGN: Controlled experiment. METHODS: Forty-four horses were randomly split into 2 groups. Lameness was measured using body-mounted inertial sensors before and after injection of xylazine (0.3 mg/kg bwt) or saline. Sedation was measured at 5, 20 and 60 min following treatment, and lameness evaluations were performed before (Time 0) and at 20 and 60 min after treatment. Forelimb lameness was determined by measuring the vector sum of mean head height maximum and minimum differences between all right and left forelimb strides (n>25) collected with the horse trotting in a straight line. Hindlimb lameness amplitude was determined by measuring mean pelvic height maximum and minimum differences between right and left hindlimb strides. Numbers of horses staying the same, improving or worsening were compared between groups at each time interval. RESULTS: There were no significant differences in head or pelvic movement asymmetry between xylazine and saline treatment groups. However, a few horses with forelimb lameness in the xylazine treatment group showed a large decrease in head movement asymmetry (decrease in forelimb lameness) at 60 min following sedation. CONCLUSIONS: Low-dose sedation with xylazine may be used without the concern of potential lameness-masking effects for hindlimb lameness evaluation, but caution should be used in some horses with forelimb lameness of mild severity. The Summary is available in German - see Supporting information.

Comparison of healing in forelimb and hindlimb surgically induced core lesions of the equine superficial digital flexor tendon.

OBJECTIVE: Even though equine multi-limb tendinopathy models have been reported, it is unknown if fore- and hindlimb tendon healing behave similarly. The aim of this study was to compare the healing process of surgically induced superficial digital flexor tendon (SDFT) core lesions of fore- and hindlimbs in horses. METHODS: Tendon core lesions were surgically induced in the SDFT of both fore- and hindlimbs in eight horses. One randomly assigned forelimb and one randomly assigned hindlimb were injected with saline one and two weeks post-surgery. The healing process was monitored clinically and ultrasonographically. After 24 weeks, the tendons were harvested and biochemical, biomechanical and histological parameters were evaluated. RESULTS: Twenty-four weeks post-surgery, the forelimb SDFT lesions had a significantly higher colour Doppler ultrasound vascularization score (p = 0.02) and glycosaminoglycan concentration (p = 0.04) and a significantly lower hydroxylysylpyridinoline content (p = 0.03). CLINICAL RELEVANCE: Our results indicate that fore- and hindlimb SDFT surgically induced lesions exhibit significant differences in several important parameters of tendon healing 24 weeks post-surgery. These differences create significant challenges in using all four limbs and accurately interpreting the results that one might generate. Therefore these findings do not support the use of four-limb models for study of tendon injury until the reasons for these differences are much better understood.

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.

Radiographic anatomy of the articular process joints of the caudal cervical vertebrae in the horse on lateral and oblique projections.

REASONS FOR PERFORMING STUDY: Plain radiography is the standard imaging technique for investigation of diseases associated with the articular process joints (APJ) of the caudal neck; however, the radiographic anatomy of these structures on both lateral and oblique radiographic projections has not previously been described in detail. OBJECTIVES: To determine the optimal technique for obtaining oblique radiographs of the APJ of the caudal cervical vertebrae (C4-5, C5-6 and C6-7) and to provide a detailed description of their normal radiographic appearance, on both lateral and oblique radiographic projections. METHODS: Radiopaque markers were used to highlight the contours of the APJ on both lateral and oblique radiographs. A novel cineradiographic technique was employed to determine the optimal oblique projection to permit both left and right APJ to be assessed on the same radiograph. Lateral and oblique radiographs of the caudal neck were obtained in 6 live horses under standing sedation to assess the feasibility of the technique. RESULTS: The radiopaque markers facilitated identification of the APJ by clearly outlining the margins of the cranial and caudal articular processes on lateral and oblique radiographs. The optimal range of angles for obtaining oblique radiographs was 50-55 degrees for C4-5, 45-55 degrees for C5-6 and 45-5 degrees for C6-7. Obtaining oblique radiographs within the specified range of angles resulted in a consistent radiographic image of the APJ in the caudal cervical region in the live individual. CONCLUSIONS AND POTENTIAL RELEVANCE: The description of the normal radiographic anatomy of the cervical APJ of the caudal neck region in horses provides a valuable reference for the interpretation of cervical radiographs. Using the standardised technique to obtain oblique radiographs of the equine cervical vertebrae may provide additional diagnostic information about the APJ.

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.

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.

[Healing process of uncomplicated sole ulcers in dairy cows kept in tie stalls: clinical description and blood chemical investigations]. / Heilungsverlauf von unkomplizierten Sohlengeschwüren bei Milchkühen in Anbindehaltung: Klinische Beschreibung und blutchemische Untersuchungen.

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]. / Das Sohlengeschwür beim Rind: Eine Literaturübersicht.

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]. / Heilungsverlauf von Klauenläsionen bei Milchkühen unter Alpbedingungen.

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.

[Capillary hemangioma, a rare neoplasia in a calf]. / Kapilläres Hämangiom, eine seltene Neoplasie beim Kalb.

A calf with a dark red, cauliflower-like mass in its oral cavity was referred to our clinic. Histopathologic examination of this mass revealed a capillary hemangioma. A combination of thermotherapy and cryosurgery was used in the treatment of this tumor. Healing was followed for one year.

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.

Ultrasonography of the umbilicus in calves. Part 2: Ultrasonography, diagnosis and treatment of umbilical diseases.

In 80 calves presented with clinical signs of umbilical disease, the umbilicus was examined by palpation and by ultrasonography using a 5 Mhz or a 7.5 Mhz sector scanner. Diagnosis was confirmed during surgery or at post mortem examination. The various diseases of the intraabdominal umbilical structures found in these calves and the therapeutic procedures performed are described in detail by use of schematic representations, photographs of anatomical preparations, and ultrasonograms. In 29 calves with an enlarged extraabdominal umbilicus, ultrasonographic examination provided additional information to determine the choice of therapy, and it was particularly helpful in calves with irreducible hernias and with umbilical abscesses. In 51 calves with diseases of the intraabdominal umbilical structures, an exact description of the extent of the disease and of the involvement of other structures, as the liver and the urinary bladder, was made possible by ultrasonography. In calves with omphalitis, early recognition of the involvement of intraabdominal umbilical structures could be determined. Umbilical ultrasonography can be performed easily and is a very reliable and informative aid not only in the diagnosis of umbilical disease but also in determining the choice of therapy. Additionally, the owner can be informed in advance about the expense and the prognosis of the planned therapy.