Equine Clinical Respiratory Techniques Flashcards
- Restraint for equine endoscopy.
- What is the entry point of all endoscopic techniques in horses?
- Handler / sedation / twitch.
- nasal passages, in ventral meatus (U shaped).
Directing the endoscope through the nasal passages.
Steer tip of endoscope slightly down sing thumb to push endoscope medially and ventrally as you pass it.
If pass up middle meatus, may hit ethmoid turbinates and cause bleeding.
Why may you choose to look in the middle meatus.
For sinusitis - sinus drainage angle.
What can be seen on entry into the pharynx/nasopharynx w/ scope?
Blind-ending dorsal pharyngeal recess.
Guttural pouch ostia dorsolaterally on the pharyngeal walls.
- How to assess guttural pouches w/ endoscope.
- How is each guttural pouch divided?
- Why are the guttural pouches important?
- Where are the retropharyngeal LNs located?
- Pass guidewire down biopsy channel of endoscope.
Pass this through guttural pouch ostia.
Rotate endoscope, then pass endoscope into guttural pouch. - Medial and lateral compartments.
Medial compartment is bigger.
Separated by stylohyoid bone. - Several nerves and vessels cross guttural pouches as they leave the cranium - infections or pathology can cause haemorrhage / deficits.
- On the floor of the medial compartment of the guttural pouch.
Guttural pouch lavage…
1. Technique.
2. Indications.
- Pass endoscope into guttural pouch.
Keep head elevated.
Pass catheter down biopsy channel.
Instil 30ml sterile saline, which will sit ventrally in the pouch.
Direct tip of catheter into saline and withdraw.
Both sides (can pool sample). - Empyema.
Detection of Strep. equi equi (‘Strangles’).
Nasopharyngeal swabbing technique.
What does nasopharyngeal swabbing achieve?
Pass long nasopharyngeal swabs via ventral meatus into nasopharynx and stimulate the horse to swallow (done blindly).
Encourages release of any discharges from the guttural pouches which are picked up on the swab.
- What comprises the floor of the nasopharynx?
– what does it separate the nasopharynx from? - Relative to the glottis, where does the soft palate sit when the horse is breathing normally?
- How is the larynx positioned in the horse and how does this affect breathing.
- Soft palate.
– oropharynx. - Underneath the epiglottis.
- Through the ostium intrapharyngium like a button through a button hole, meaning the horse is an obligate nasal breather.
Endoscopy during exercise.
Of pharynx/larynx region.
More accurate than at rest.
Most places use overground endoscopy (telemetered equipment).
Treadmill endoscopy used prior to this.
What is laryngeal ultrasound useful for?
Assessment of laryngeal cartilages and echogenicity of musculature.
- Sinoscopy / sinus trephination
- Common sites of trephination.
- Allows direct visualisation of the sinus structures / pathology.
Trephination also performed for placement of a foley catheter in order to lavage sinuses if sinusitis present. - Frontal sinus - 0.5cm caudal to a line drawn between the left and right medial canthi, and halfway between midline and ipsilateral medial canthus.
Caudal maxillary sinus - 2cm caudal and 2cm ventral to medial canthus of the eye.
Head radiographs.
Portable x-ray units.
Enhanced ability to examine areas of the respiratory tract as normally air contained here.
Sedate horse and put head on a head stand.
Head radiograph - lateral view.
Useful for some of the paranasal sinuses and nasal passages.
Everything else quite superimposed w/ a lateral view.
Head radiographs - dorsoventral view.
Can compare one side to the other.
Much of nasal passage and paranasal sinuses obscured by mandible and teeth.
Limited usefulness to evaluating midline structures.
May study nasal septum, common nasal meatus, and maxillary sinus.
Head radiographs - oblique views.
Best images to evaluate maxillary sinuses, frontal sinuses and both dental arcades.
Important in evaluation of teeth roots since they are projected free of other bony or dental structures.
