Musculus levator ani
The levator ani forms part of the muscular floor of the pelvis along with the coccygeus. It originates from the pelvic surface of the ilium and ischiatic spine and inserts on the caudal vertebrae and perineal body. Its actions include supporting the pelvic floor, compressing the rectum, and drawing the tail ventrally. It is innervated by the pudendal and caudal rectal nerves (roughly S3–S5). It is important for defecation and maintaining perineal conformation. Perineal lacerations during foaling can damage this muscle and related structures.
Origin: Pelvic surface of the ilium and ischiatic spine
Insertion: Caudal vertebrae and perineal body
Action: Supports the pelvic floor; compresses the rectum; draws the tail ventrally
Innervation: Pudendal and caudal rectal nerves (S3-S5)
Relevant in foaling injuries and perineal reconstruction. Damage can affect fecal continence or reproductive conformation.
## Overview Perineal laxity is weakness of the muscles and connective tissue supporting the perineum, common in older multiparous mares. It contributes to a sunken or tilted perineal conformation, fe
## Overview Cauda equina syndrome is a constellation of neurologic signs caused by disease of the nerve roots that form the cauda equina at the end of the spinal cord. Affected horses show varying co
After a difficult foaling, have the mare checked for perineal tears or trauma. Swelling or abnormal conformation in the perineal area should be evaluated.
## Overview Perineal laxity is weakness of the muscles and connective tissue supporting the perineum, common in older multiparous mares. It contributes to a sunken or tilted perineal conformation, fecal retention, pneumovagina, and increased risk of rectal prolapse. Surgical procedures such as Caslick’s or perineal body reconstruction are often required. ## Causes Repeated foaling, age-related weakening, or previous trauma. ## Diagnosis Visual and manual examination of perineal conformation and vaginal integrity. ## Treatment Caslick’s procedure for pneumovagina, or more extensive perineal reconstruction for significant laxity. Management of manure consistency. ## Recovery and Prognosis Good with appropriate surgical correction. ## Prevention Careful management of foaling and prompt repair of perineal trauma. Signs include: sunken or tilted perineal conformation; fecal retention; rectal prolapse risk; pneumovagina
## Overview Cauda equina syndrome is a constellation of neurologic signs caused by disease of the nerve roots that form the cauda equina at the end of the spinal cord. Affected horses show varying combinations of hind-limb weakness, urinary incontinence, fecal retention, and loss of tail tone. Causes include trauma, equine protozoal myeloencephalitis, polyneuritis equi, and space-occupying lesions. ## Causes Trauma to the sacrum, infectious or inflammatory neuritis, protozoal myelitis, and neoplasia can all damage the cauda equina. The specific cause determines treatment and prognosis. ## Diagnosis Neurologic examination demonstrates lower-motor-neuron signs to the tail, anus, bladder, and hind limbs. Rectal examination, cerebrospinal fluid analysis, and advanced imaging help identify the lesion. Testing for Sarcocystis neurona or other infectious agents is often performed. ## Treatment Therapy is directed at the underlying cause when known (antiprotozoal drugs, anti-inflammatories, or surgical decompression). Supportive care includes bladder management, fecal softeners, and prevention of urine scald. ## Recovery and Prognosis Prognosis is guarded and depends on the cause and severity. Some horses with inflammatory disease improve; severe trauma or advanced denervation often leaves permanent deficits. ## Prevention No specific prevention exists beyond minimizing sacral trauma and controlling known infectious risks where possible. Signs include: hindlimb weakness or ataxia; urinary incontinence; fecal retention; reduced tail tone; muscle atrophy of the hindquarters in chronic cases
Relevant in foaling injuries and perineal reconstruction. Damage can affect fecal continence or reproductive conformation.
After a difficult foaling, have the mare checked for perineal tears or trauma. Swelling or abnormal conformation in the perineal area should be evaluated.
See the Levator Ani on our interactive 3D horse model. Open 3D Model