Equine Neck

Equine Anatomy and Surgery Overview

1. Introduction to Equine Net and Overhack

  • Discussion of the equine skull and its anatomy.

2. Skull Anatomy

  • Detailed examination of three bones in the skull.

  • Three external features of the skull were identified.

3. Nerve Blocks in Equine Medicine

  • Nerve blocks discussed:

    • Three blocks for the face.

    • Five blocks for the eye.

  • Major nerves supplying the head and eyes identified:

    • Trigeminal nerve: responsible for sensation in the face and motor functions such as biting and chewing.

    • Facial nerve: responsible for the muscles of facial expressions and some taste functions.

4. Internal Structures of the Head

  • Overview of internal structures:

    • Nostrils: distinction between true and false nostrils.

    • Nasolacrimal ducts: responsible for draining tears from the eyes.

    • Nasal septum, concha, and nasal sinuses: structures within the nasal cavity.

5. Laryngeal and Nasopharyngeal Anatomy

  • Importance of understanding:

    • Larynx and nasopharyngeal area: critical for surgery and treatments like laryngeal hemiplegia.

    • Lateral pouches: relevant in surgical considerations.

6. Neck Anatomy

  • Discussion of an essential anatomical region known as the fibre triangle, critical for accessing the ductus tail.

  • Introduction to various muscles in the neck:

    • Muscles identified:

    • Gliomastoidus.

    • Omotransversarius.

    • Sternocephalicus

    • Omohyoideus.

    • Sternohyoideus and sternothyroideus: thin muscles essential for separation during tracheotomy/tracheostomy.

7. Fascia of the Neck

  • Importance of superficial vs. deep fascia:

    • Superficial fascia: loose irregular connective tissue, encasing muscles and the jugular groove.

    • Deep fascia: dense regular connective tissue surrounding vital structures such as the trachea and esophagus.

    • Communication between the two fascia types discussed.

8. Tracheotomy and Tracheostomy Procedures

  • Tracheotomy: performed in emergencies.

  • Tracheostomy: done in surgical settings under progressive conditions (e.g., tumors obstructing the airway).

    • A focus on the importance of cutting 4 to 6 cartilage rings and annular ligaments and the method of elliptical incisions for access during these procedures.

9. Lymphatic System of the Equine Head and Neck

  • Overview of lymphatic structures:

    • Three deep cervical lymph centers: cranial, middle, and caudal.

    • Important for equine health, particularly in jumpers.

10. Esophageal Anatomy

  • Location of the esophagus in relation to the trachea (dorsal to trachea but shifts left at the neck).

  • Clinical implications in procedures like passing a nasogastric tube or endoscope, highlighting the significance of anatomical knowledge for prevention of complications.

  • Importance of deep fascia communication with the esophagus and trachea regarding potential infection pathways and related health risks (e.g., pneumonia).

11. Nuchal Ligament Anatomy

  • Anatomical significance of the nuchal ligament:

    • Provides elasticity for the horse’s heavy head, aiding in grazing and movement.

    • Consists of two parts:

    • Cord-like part: extends from the back of the skull along the dorsal midline of the cervical vertebrae.

    • Laminar part: has different structural functions.

  • Detailed discussion on interdigitation with the supraspinous ligament and thoracolumbar fascia, supporting limb mechanics without articulated joints of the forelimbs.

12. Bursa and Infections Associated with Nuchal Ligament

  • Identification of cranial nuchal bursa:

    • Risks associated with skin barrier injuries leading to cranial nuchal bursitis (Pole Evo disease).

    • Rubbing injuries leading to inflammation and fluid accumulation in the bursa.

  • Discussion of caudal nuchal bursa and its less frequent incidence of bursitis.

  • Supraspinous bursa: includes risk of infection associated with specific bacteria like Brucella.

13. Importance of Physical Condition

  • Link between anatomical knowledge and health management, especially for equine athletes.

  • Recognizing a solid understanding of bruises, bursa inflammation, and associated structures in relation to potential disease transmission to humans involved in equine care (e.g., Brucellosis).

14. The Spinal Canal and Neurological Assessments

  • Identification of the anatomical landmark in spinal assessments: dorsal midline, cranial to the wings of the atlas.

  • Usage in collecting cerebrospinal fluid and potential for injecting radiopaque substances for diagnostic measures.

  • Importance in evaluating cases of stenosis and conditions like intervertebral disc disease.

15. Cervical Vertebral Malformation

  • Discussion of wobblers, conditions such as cervical vertebral malformation or stenotic myelopathy, emphasizing the importance of sagittal ratios in evaluating healthy spinal canal dimensions.

  • The sagittal ratio is described as:

    • Depth of the spinal canal (measurement a) divided by length of the vertebral body (measurement b). The typical ratio for healthy anatomy is approximately between 50-52%.

  • Clinical cases are mentioned, emphasizing differences in measurements between dogs and horses.

16. Bone Scanning Techniques

  • Introduction to nuclear medicine in bone scanning, especially for detecting inflammatory or infected bony structures. Radioactive iodine-125 is utilized for this purpose to indicate areas of increased blood supply due to inflammation,

  • The imaging referred to as nuclear syntaggis, resulting in a visual differentiation of infected areas and the implications regarding veterinary practice and diagnosis of bone-related issues in equines.

17. Summary of Techniques and Considerations

  • Reiterate the importance of detailed anatomical understanding for successful equine surgical procedures and clinical diagnostics.

  • Emphasis on vital structures in maintaining equine health and safety in veterinary practices, linking anatomical knowledge to clinical application.

18. Conclusion

  • The importance of hitting key anatomical landmarks for accurate treatment and diagnosis.

  • Continuous interaction with equine anatomy and conditions discussed enhances understanding of veterinary practices.