Page 560 - The Veterinary Care of the Horse

• It may begin early in life as, during the birth process, the thoracic vertebrae that form the

withers and the associated ribs can be traumatized by pressure. Research indicates that up
VetBooks.ir to 20% of newborn foals have a degree of ribcage trauma and as many as 5% sustain rib
fractures. This may lead to irritation of the 2nd–6th thoracic nerves that innervate the

girth area, and heightened sensitivity of the local muscles behind the elbow.
• It may also lead to uneven weight-bearing on the forelimbs causing asymmetric

development of the shoulder musculature and consequent difficulties with saddle fit.

• A saddle that is too narrow and pinches the withers can trigger the problem.
• Another cause of girth sensitivity is gastric ulceration.

• Overtightening of the girth can cause pain and breathing difficulties.

Many horses tolerate a low grade of discomfort, showing only subtle signs that are often
missed. This may be exacerbated by an increase in the level or type of work, a fall, or the
problem going unrecognized for a long time and gradually getting worse. Once the condition

has developed, anxiety and fear on the horse’s part may lead to increased spookiness or to the
extreme reactions sometimes encountered.

Clinical signs

• Many horses are sensitive in their girth regions. In some, however, running a finger down
the girth region behind the elbow causes the muscles to jump markedly, causing

discomfort and anxiety.
• These horses have no visible lesions but they are often uncomfortable when brushed.

• Tightening the girth causes the horse to swish its tail, toss its head, grunt in discomfort or

move away. Less obvious signs include a change in facial expression or breathing
pattern. Some horses will momentarily stop chewing hay.

• The horse may turn round and try to bite the handler or kick out at the girth.

• Some affected animals will breathe in to expand the chest as the girth is done up in an
attempt to stop it being tightened.

• Many of these horses have pain in the trapezius muscle (which is supplied by the same
thoracic nerves) that is directly under the front of the saddle. Firm stroking of this muscle

often causes the horse to give a violent shudder of the muscles over the girth area and to
move away or dip down.

• Severely affected horses jump or even collapse when the girth is tightened or
immediately afterwards.