Musculus sacrocaudalis dorsalis lateralis
The sacrocaudalis muscles are the primary muscles controlling the equine tail. The sacrocaudalis dorsalis lateralis elevates and laterally deviates the tail. The sacrocaudalis dorsalis medialis elevates the tail dorsally (lifts it straight up). The sacrocaudalis ventralis lateralis depresses the tail and assists in lateral movement. The sacrocaudalis ventralis medialis depresses the tail ventrally (pulls it down). They originate from the sacral and caudal vertebrae and insert on the corresponding caudal vertebrae. All are innervated by the caudal (coccygeal) spinal nerves.
Origin: Articular processes of sacral and caudal vertebrae
Insertion: Dorsolateral caudal vertebrae
Action: Elevates the tail and moves it laterally
Innervation: Caudal (coccygeal) spinal nerves
Isolated injury is uncommon. Tail tone and movement are assessed in neurologic examinations. Trauma to the tail or sacrocaudal region can affect these muscles and associated nerves. Relevant in evaluations of cauda equina or sacral nerve dysfunction.
## 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
Persistent abnormal tail carriage, weakness, or asymmetry after trauma should be evaluated. Protect the tail from injury during transport and handling.
## 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
Isolated injury is uncommon. Tail tone and movement are assessed in neurologic examinations. Trauma to the tail or sacrocaudal region can affect these muscles and associated nerves. Relevant in evaluations of cauda equina or sacral nerve dysfunction.
Persistent abnormal tail carriage, weakness, or asymmetry after trauma should be evaluated. Protect the tail from injury during transport and handling.
See the Sacrocaudalis Dorsalis Lateralis on our interactive 3D horse model. Open 3D Model