A novel dynamometer for the standardisation of the force applied during distal forelimb flexion tests in horses

Variability in the technique employed for flexion tests may produce different responses and veterinary assessments. We propose a novel custom-designed dynamometer and compare the results with the literature. Ten horses were enrolled in the present study, with a total of 20 forelimbs. The horses were found to be healthy based on orthopaedic and radiographic examination of the distal forelimb region, performed on both limbs. Lower forelimb flexion tests were performed by applying three different forces (75, 100 and 120 N), measured with a dynamometer, for one minute, with a time interval of 48 h between each test. Each horse was trotted before and after the flexion test. The experiment was videotaped, and the responses were assessed randomly and blindly by three experienced equine veterinarians. None of the horses responded with a lameness grade exceeding 1/5 on a numerical 6-point scale. Two out of three veterinarians detected a increased degree of lameness between the minimum and the maximum force applied, while one veterinarian showed no change in the interpretation of the flexion test for all three applied forces. A mild agreement was detected between veterinarian A and B, applying a force of 100 N, and between A and C, with 120 N; a moderate agreement was found between veterinarian A and B, with 120 N. The chi-square test showed that the results observed were only like the expected ones for 100 N. With a force of 100 N, there is no relationship between intensity and the evaluation of lameness; consequently, 100 N could be used to achieve a real standardisation of the lameness score. The use of the dynamometer was found to be easy and practical. It also enabled the applied force and the manipulation technique to be objectified.     

Comparison of distal forelimb conformations between Japanese Black and Holstein-Friesian newborn calves

Flexural and hyperextension deformities are congenital problems in calves. We, therefore, aimed to investigate the distal limb conformation in 1 day- and 28-day-old female Holstein-Friesian (HF) calves (n=21), male Japanese Black (JB) calves (n=15), and female JB calves (n=15). The claw angle of the forelimb dorsal claw wall in a standing position and recorded other parameters, including body weight, withers height, circumference of forelimbs, and flexor tendon thickness in the forelimbs, were measured and compared these between the three groups. At 1 day old, the mean claw angles were 51.1° in female HF calves, 47.0° in male JB calves, and 41.8° in female JB calves; the 95% confidence intervals (CIs) of the claw angles showed large distributions in all three groups. One female HF and one male JB calves showed mild flexural deformity, whereas four JB calves showed hyperextension deformity. At 28 days old, the mean claw angles were 51.7° in female HF calves, 51.2° in male JB calves, and 48.4° in female JB calves; the 95% CIs of the claw angles showed smaller distributions than those at 1 day old in all groups. For all groups, the limb deformities had improved without treatment at 28 days old. As a feature of the breed, female JB calves were apt to show hyperextended deformities inversely proportional to the body weight. These limb deformities healed spontaneously and were thought to be physiological.     

The influence of breed,age, gender,training level and ambient temperature on forelimb and back temperature in racehorses

A previous thermographic study of racehorses identified 13 regions of interest (ROIs) for monitoring the impact of training. However, that investigation did not consider the influence of breed, age, gender or training intensity level on the temperature of ROIs. The present study adopted a multivariate analysis approach to determine whether the aforementioned factors, along with ambient temperature, significantly influenced ROI temperature in the key body regions. Thermography measurements were obtained from 53 racehorses of three breeds. Horses were in regular training for over 10 months, having 13 thermographic examinations in each racing season. Backward stepwise multiple linear regression indicated that ambient temperature and breed contributed significantly to the model for predicting ROI temperature at all 13 ROIs. Training intensity level contributed significantly to the model only at the thoracic vertebrae, the left third metacarpal bone and left fetlock joint. Neither gender nor age contributed to the model significantly at any ROI. Our data suggest that ambient temperature, breed and training level affect racehorse body surface temperature in some areas of the distal parts of the forelimbs and the back. This contributes to a better understanding of the normal range of thermographic findings in racehorses undergoing intensive training.     

A large cyst in the distal femur of a horse

A 10-year-old Warmblood gelding presented with a left hindlimb lameness. Diagnostic analgesia located the lameness to the stifle. Radiography showed an unusually large cyst in the distal femur. Diagnostic arthroscopy of the stifle did not reveal any significant abnormalities. An extra-articular transcortical approach to the cyst was performed for drainage, curettage, and provision of an autologous, cancellous bone graft, gentamicin-impregnated collagen fleeces and injectable steroid. The horse returned to a higher level of competitive dressage than prior to surgery. This report describes a large cyst in the distal femur of a horse.     

The use of computed tomography to diagnose bilateral forelimb tendon pathology in a horse with unilateral lameness

A horse with unilateral forefoot lameness had bilateral deep digital flexor tendon (DDFT) lesions on computed tomography (CT). Venous contrast enhanced CT revealed distal sesamoidean impar desmitis in the lame forelimb. Computed tomography is useful for diagnosis of soft tissue lesions within the hoof capsule and contrast enhancement improves lesion conspicuity.     

Differences in the morphology of distal border synovial invaginations of the distal sesamoid bone in the horse as evaluated by computed tomography compared with radiography

Reasons for performing study: Distal border synovial invaginations of the distal sesamoid bone are radiographically assessed during the selection process of horses admitted as breeding stallions or in purchase examinations. Nowadays, many moderately or some deeply penetrating proximally enlarged synovial invaginations are considered as moderate or severe radiographic findings. Objective: To measure the difference between and agreement of the morphology of distal border synovial invaginations on radiography vs. computed tomography (CT). It was hypothesised that the morphology of distal border synovial invaginations would be better evaluable on CT compared with radiography. Methods: Computed tomography scans and 3 dorsoproximal–palmarodistal oblique (DPr‐PaDiO) radiographs were obtained on 50 cadaver forefeet from 25 Warmblood horses. Computed tomography was assumed to be the gold standard. The number, shape and depth of penetration of distal border synovial invaginations into the distal sesamoid bone were evaluated with both methods, and the comparison of their measurements was statistically described. Results: A statistically significant mean difference for number of distal synovial invaginations between CT and all 3 DPr‐PaDiO projections was found and was approximately equal to 2, meaning that CT permits visualisation of an average of 2 more invaginations than radiography. In none of the cases did radiography have a higher number observed than CT. A large variation in the difference of measurements for depth of penetration against their mean difference between CT and the 3 radiographic projections was seen. Radiography underestimated the depth of invaginations, and more so when these were deeper. There was no statistically significant mean difference found between the techniques for depth. A moderate to good agreement between measurements on CT and the three DPr‐PaDiO projections for shape was seen, in which the D55°Pr‐PaDiO projection showed the best agreement. A high specificity (90–99%) and low sensitivity (65%) for all projections for shape were found. Conclusions and potential relevance: Radiography differs considerably from CT concerning the morphology of distal navicular border synovial invaginations. For the evaluation of the number, depth and shape of distal synovial invaginations in the distal sesamoid bone, radiography shows only partially the morphology seen on CT.     

A review of regional limb perfusion for distal limb infections in the horse

Regional limb perfusion (RLP) is a technique widely used for the treatment of limb infections in horses. The objective is to deliver high concentrations of an antimicrobial to a focal region to optimise the bacterial kill with minimal systemic effects. However, experimentally, realising these objectives has been unreliable because conflicting methodologies have produced highly variable results. The aim of this study is to review all of the experimental and clinical literature on RLP between 1990 and 2019 to determine whether there is evidence that RLP has a consistent and practical application for the treatment of distal limb infections in equine practice. A large number of reports have been published on RLP in the horse; however, there are many variations in the technique including the drug used, dose, volume and concentration of perfusate, dosing interval, the type, method and duration of application of the tourniquet and whether the procedure is performed standing or anaesthetised. Prospective clinical studies are lacking, retrospective studies are limited by their nature, while wide differences in treatment regimen and methodology in retrospective and experimental studies have complicated the interpretation of the findings and make it difficult to rationalise an approach that provides a reliable and repeatable outcome. The optimal method of performing RLP has not been established, so the apparent clinical benefits of the technique are often difficult to confirm and quantify. Future studies need to standardise methodologies to enable meaningful comparisons.     

Ultrasonographic examination of the dorsal aspect of the distal interphalangeal joint of the horse

Ultrasonographic examination of the dorsal aspect of the distal interphalangeal joint is part of the routine examination of the foot structures. The purpose of this paper is to describe the ultrasonographic anatomy of the area, and normal transverse and longitudinal images. Clinical cases are presented to illustrate abnormal findings and lesions of the dorsal aspect of the joint. Ultrasonography can complement radiography for the diagnosis and documentation of many soft tissue and joint abnormalities such as synovitis, fluid distension, cartilaginous defects, periarticular osteophytes and bone fragments.     

Anatomic variations and degenerative changes in the collateral cartilages and middle and distal phalanges of the forelimb in Ardenner colts

The anatomic variations and the degenerative changes in the collateral cartilages and middle and distal phalanges in 6 Ardenner colts were characterized by radiography, scintigraphy, and magnetic resonance imaging (MRI). The radiographic changes were assessed between the ages of 16.5 and 25 months. An anatomic variation of the middle and distal phalanges was demonstrated in some of the colts. MRI examination of the 6 colts revealed an association between the deep digital flexor tendon cross-sectional area and body weight as well as foot circumference. Also, a thin collateral sesamoidean (suspensory navicular) ligament was observed subjectively. The presence of an extensive ossification of the collateral cartilages of the foot was found in these young horses. The ossification was characterized by the existence of 2 separate ossification centers, which had a tendency to unite. The radiographic interphalangeal degenerative lesions seen appear as bone remodeling of the dorsal edges of the middle and distal phalanx, on the insertion sites of collateral ligaments of the distal interphalangeal joint, the digital extensor tendon, and the distal interphalangeal joint capsule.     

Ultrasonographic examination of the caudal structures of the distal antebrachium in the horse

Evaluation of the caudal distal antebrachium using ultrasound is a very useful diagnostic procedure for identification of soft tissue abnormalities in flexor structures of the equine limb. In this article we describe how ultrasonographic imaging may be used to complement radiography of the carpus in evaluating horses that present with peri‐carpal swelling and/or lameness localised to the carpal region. Ultrasonographic examination assists with the identification or exclusion of significant injuries to muscular, tendonous and ligamentous structures within the distal antebrachium and enables practitioners to proceed with appropriate therapeutic and rehabilitation plans for the immediate benefit for their patients while also recognising pathology that could progress to cause long‐term, chronic lameness issues without aggressive and effective intervention.     

The effect of rising and sitting trot on back movements and head‐neck position of the horse

Reason for performing study: During trot, the rider can either rise from the saddle during every stride or remain seated. Rising trot is used frequently because it is widely assumed that it decreases the loading of the equine back. This has, however, not been demonstrated in an objective study. Objective: To determine the effects of rising and sitting trot on the movements of the horse. Hypothesis: Sitting trot has more extending effect on the horse's back than rising trot and also results in a higher head and neck position. Methods: Twelve horses and one rider were used. Kinematic data were captured at trot during over ground locomotion under 3 conditions: unloaded, rising trot and sitting trot. Back movements were calculated using a previously described method with a correction for trunk position. Head‐neck position was expressed as extension and flexion of C1, C3 and C6, and vertical displacement of C1 and the bit. Results: Sitting trot had an overall extending effect on the back of horses when compared to the unloaded situation. In rising trot: the maximal flexion of the back was similar to the unloaded situation, while the maximal extension was similar to sitting trot; lateral bending of the back was larger than during the unloaded situation and sitting trot; and the horses held their heads lower than in the other conditions. The angle of C6 was more flexed in rising than in sitting trot. Conclusions and clinical relevance: The back movement during rising trot showed characteristics of both sitting trot and the unloaded condition. As the same maximal extension of the back is reached during rising and sitting trot, there is no reason to believe that rising trot was less challenging for the back.     

Ultrasonographic examination of the distal podotrochlear apparatus of the horse: A transcuneal approach

In the diagnostic work‐up of lameness originating from the foot, ultrasonographic examination is an essential complement to radiography for the detection of soft tissue lesions of the podotrochlear apparatus (PTA). The infrasesamoidean part of the deep digital flexor tendon, distal sesamoidean ligament and distal sesamoid bone can be accurately assessed using a transcuneal approach. This paper describes the ultrasonographic technique and presents normal and abnormal ultrasound images of the infrasesamoidean part of the PTA.     

Treatment of a subchondral cystic-like lesion in the distal scapula with a translesional bone screw in a horse

A 2-year-old French Warmblood stallion was presented for lameness investigation. The diagnostic procedures identified the reason for lameness as being a subchondral cystic-like lesion (SCL) in the glenoid cavity of the scapula. The horse was surgically treated with a translesional 4.5 mm cortical bone screw inserted through the SCL under radiographic guidance. Sixty days after surgery, the horse was sound and the SCL showed significant radiographic signs of healing. Radiographs obtained 180 days after surgery showed further radiographic healing, with the SCL presenting a radiodensity similar to the surrounding bone. At 4 years post-operative follow-up, the horse is sound and competing successfully as a 6-year-old in Concours de Saut International (CSI) competitions.     

Computed tomographic (CT) arthrogram contributes to the diagnosis of an osteochondroma of the distal calcaneus in a horse

Osteochondromas in the horse are most commonly found as a solitary lesion affecting the distal radial metaphysis. In this location, diagnosis is reliant on radiographic and ultrasonographic examination and confirmed with post-operative histopathology. This case report describes the additional benefit of performing a CT arthrogram to aid the diagnosis of an osteochondroma in an atypical location.     

Eosinophilic intestinal diseases of the horse

Eosinophilic intestinal diseases of the horse are not commonly reported. Similar diseases are reported in man, but for either species, these eosinophilic diseases, are poorly understood. Eosinophilic intestinal disease may be accompanied by eosinophilic disease of other organs, or eosinophilia may be restricted to the intestine. When infiltration of eosinophils is restricted to the intestine, horses have a good prognosis for resolution of clinical signs, even though the treatment may include celiotomy with intestinal decompression or resection and administration of a corticosteroid. When eosinophilic intestinal disease is accompanied by infiltration of other organs, such as skin, pancreas, lungs or liver, the horse's prognosis for survival is very poor.