EQUINE | Equine Disease Update
EQUINE | Equine Disease Update
servations , we have studied normal horses subjectively free from lameness in hand , after flexion test , on the lunge on both soft and firm surfaces and when ridden . We objectively measured body lean on the lunge and range of movement of the thoracolumbar region using inertial measurement units placed at predefined locations on the thoracolumbar and pelvic regions . These studies established normal ranges of motion for the thoracolumbosacral spine and demonstrated that sound horses have a small degree of bilaterally symmetrical body lean on the lunge . We also measured body lean on the lunge in lame horses and demonstrated that there is frequently asymmetry between left and right reins , with greater lean compared with normal Observation , Science , and Equine Lameness Diagnosis on at least one rein .
Substantial improvement in lameness by performing diagnostic analgesia resulted in reduced body lean on both reins and reestablishment of symmetry between left and right reins . Likewise , when lameness was improved by diagnostic analgesia , range of motion of the thoracolumbosacral regions increased , especially in the caudal thoracic and lumbar regions . We have observed that the tendency of a saddle to slip persistently to one side is most frequently associated with hindlimb lameness . Abolition of lameness by diagnostic analgesia results in resolution of the saddle slip . The saddle most commonly slips to the side of the lame or more lame hindlimb , but less frequently slips toward the less lame limb . Presumably saddle slip is induced by altered range of motion of the thoracolumbosacral region , which may vary among horses . Saddle slip may actually be an indicator of the likely presence of hindlimb lameness . Overt lameness may not be apparent when a horse is trotting , but musculoskeletal pain may be manifest at a canter by the horse ’ s tendency to become disunited or repeatedly change leading limbs behind or in front , crookedness , loss of a normal three time rhythm , placing the hindlimbs either abnormally close together spatially and temporally , or placing the limbs remarkably far apart . These observations may be apparent either on the lunge or when the horse is ridden . Abolition of baseline lameness seen in hand may paradoxically make the canter appear worse if sacroiliac pain is contributing to pain and poor performance . These observations highlight the importance of evaluating horses with performance problems both in hand , on the lunge and ridden , preferably by the normal rider . Horses should be assessed in walk , trot , and canter , bearing in mind that while one aspect of the gait may improve with diagnostic analgesia , another may deteriorate . Horses should also be assessed performing the movements which they find most difficult , because in some horses this may be the only condition when the problem is manifest .
Contact : Sue Dyson , MA , VetMB , PhD , DEO , FRCVS sue . dyson @ aht . org . uk + 44 ( 0 ) 1638 7519098 Centre for Equine Studies , Animal Health Trust Newmarket , Suffolk , UK
NATIONAL Equine Coronavirus – An Emerging Enteric Virus of Adult Horses
Equine coronavirus ( ECoV ) is classified within the Betacoronavirus genus , along with bovine coronavirus , porcine hemagglutinating encephalomyelitis virus , mouse hepatitis virus , rat coronavirus ( sialodacryoadenitis virus ), and certain human coronaviruses such as OC43 , HKU1 , Severe Acute Respiratory Syndrome coronavirus , and Middle East Respiratory Syndrome coronavirus ; the latter two viruses have caused epidemic outbreaks of respiratory disease in human beings in the last decade . ECoV has been recently associated clinically and epidemiologically with emerging outbreaks of pyrogenic and enteric disease in adult horses in Japan and anorexia , lethargy , and fever in the United States . Coronavirus infection typically be-
• Volume 19 no 1 • February 2017 • 27