Disease of the equine head and neck 3 Flashcards
Describe the anatomy and innervations of the nares/nostrils
- Alar folds
- Supported by alar cartilages
- Facial nerve innervation
- Nasal diverticulum (false nostril)
Name some nasal disorders
- Trauma: lacerations
- Facial nerve paresis /
paralysis - Nasal atheroma
- Alar fold collapse
When can Facial nerve paresis/paralysis occur?
Uncommon
- General anaesthesia / recumbency where pressure over facial nerve
- Iatrogenic e.g. surgery of the face
- Most often temporary paresis, will resolve with time
What are the clinical signs of Facial nerve paresis/paralysis?
- Facial swelling
- Asymmetry
- Reduced airflow
- Nasal stertor
+/- facial distortion - Poor performance
How is facial nerve paralysis/paresis diagnosed?
Observation
Palpation
How should acute lacerations be treated and managed?
- Full thickness defects: precise anatomical repair
important to preserve ability to dilate fully - Minimal debridement: good blood supply, preserve the tissues
- 2 or 3 layer closure: appropriate suture materials
and size - Monitor for rubbing of sutures (+/- stent over the site)
What are the considerations of chronic scarring following a facial laceration?
- Performance limiting: reduced nasal airflow
- Cosmetics may be important
- Reconstructive surgery possible
An epidermal inclusion cyst is also known as?
A nasal artheroma
Where is an epidermal inclusion cyst located?
Cyst within nasal diverticulum (false nostril)
What is the clinical sign of an epidermal inclusion cyst?
Non-painful swelling at Nasoincisive notch
How are epidermal inclusion cysts diagnosed?
History, visual appearance, histopathology
Describe the treatment and prognosis of an epidermal inclusion cyst
- Surgical removal (usually under local anaesthesia +
standing sedation) - Formalin treatment reported but risk of necrosis (not recommended)
- Excellent prognosis with surgical removal; likely to recur with simple drainage.
Describe the features and signs of alar fold collapse
Flaccid or redundant alar folds:
- Respiratory tract noise at exercise – fluttery sound
- Exercise intolerance in performance horses
Pathogenesis = Unknown
How is alar fold collapse diagnosed and treated?
- Fluttering sound at exercise (DDx laryngeal /soft palate disorders)
- Temporary sutures
- Resection of the alar folds
Which structures separate the L and R nasal passaged?
Nasal septum and vomer bone
Describe the dorsal and ventral conchae (turbinates)
- Thin scrolls of cartilage & bone
- Divide the nasal passages into 3 meati: dorsal, middle, ventral
- Form the conchal sinuses caudally
Describe the sinus drainage angle
- Narrow passageway where paranasal sinuses drain into the nasal passages
- Usually 2-3mm diameter – cannot directly access the paranasal sinuses in normal horses using nasal endoscopy
- Horses present with a unilateral nasal discharge as drainage occurs rostrally to the nasal septum
What are the 2 key anatomical features of the nasal passages?
- Sinus drainage angle
- Ethmoidal turbinates
Name 2 congenital disorders of the nasal passages
- Wry nose (nasal septum deviation)
- Choanal atresia (rare)
Name 4 acquired disorders of the nasal passages
- Trauma (iatrogenic common)
- Progressive ethmoid haematoma (PEH)
- Fungal rhinitis
- Foreign bodies (rare)
Clinical Signs Of nasal passage disease that may be seen include:
- Nasal Discharge
- Abnormal Respiratory Noise
- Dyspnoea
- Malodorous smell
- Facial / nasal Distortion
- Head Shaking
- Snorting / rubbing nose
What are the features of nasal trauma?
- Epistaxis
- Kick / blunt trauma
- Iatrogenic: trauma during nasogastric intubation / endoscopy (common)
- Haemorrhage usually stops within 5-10 minutes
How can iatrogenic trauma be avoided when tubing?
- Ensure tube placement in the VENTRAL meatus not middle meatus (more likely to traumatise ethmoturbinates)
- Use a smooth tube
- Lubricant on the end of the tube
- Do not force the tube when you meet resistance
Describe the features of a progressive ethmoid haematoma
- Encapsulated non-neoplastic mass
- Unknown aetiology
- Locally invasive (doesn’t
metastasise) - Grows into the nasal passages / paranasal sinuses
- Removal to be curative
What are the clinical signs of a progressive ethmoid haematoma?
• Epistaxis (nasal passages / sinuses)
- Usually intermittent
- Often slightly brown / red colour
• +/- Facial swelling (sinuses)
How are nasal progressive ethmoid haematomas diagnosed?
- Endoscopy: characteristic yellow / green lesion on ethmoid
+/- computed tomography
How are sinus progressive ethmoid haematomas diagnosed?
- Radiography
- Sinoscopy
- Computed Tomography: assess cribriform plate
• Possible intracranial extension
• Formalin contraindicated for treatment
How would you treat a progressive ethmoid haematoma in the nasal passages?
Intra-lesional formalin: • ***CT first*** • Assess cribiform plate • Multiple formalin injections - +/- Laser excision/ablation: • If small • Post formalin treatment
How would you treat a progressive ethmoid haematoma in the sinuses?
Sinus flap surgery
- Treat sinusitis
- Remove lesions +/- laser
What is the other name for fungal rhinitis?
Nasal aspergillosis
What are the clinical signs of fungal rhinitis?
- Unilateral purulent / haemorrhagic nasal discharge
- +/- Malodorous smell
- Occasionally nasal stertor
How is fungal rhinitis diagnosed?
Endoscopy
Fungal culture
How is fungal rhinitis treated?
- Removal of fungal plaques & necrotic bone
- Topical antifungal treatment
Enilconazole lavage (‘Imaverol’)
How main pairs/groups of paranasal sinuses are there?
7 pairs of paranasal sinuses
2 functional groups - rostral and caudal
What is the key point of information to know about the paranasal sinus groups?
No communication between groups!!!
Sinuses within each group share drainage
into the nasal passages
Name the paranasal sinuses in the rostral group
Rostral maxillary (RMS) Ventral conchal (VCS)
Name the paranasal sinuses in the caudal group
Caudal maxillary (CMS) Frontal (FS) Dorsal conchal (DCS) Sphenopalatine (SP) Ethmoid sinus (ES)
What structure separates the rostral and caudal groups of sinuses?
Oblique bony septum
Describe conchal bullae
Separated from the paranasal sinuses
Air filled regions that sit rostral to these but they can become infected
Name the 2 most common paranasal sinus diseases
Primary sinusitis
Secondary sinusitis
Name 4 less common paranasal sinus diseases
- Sinus cysts
- Sinus progressive ethmoid haematoma
- Neoplasia
- Trauma
What are the 2 most common presentations with paranasal sinus disease?
- Nasal discharge
- Facial swelling
What are the clinical signs of paranasal sinus disease
• Predominantly UNILATERAL nasal discharge (may be bilateral if bilateral sinus disease) • Nature of discharge may assist diagnosis: - Serous - Purulent - Mucopurulent - Haemorrhagic • +/- Facial swelling • +/- Facial deformity • +/- Decreased nasal airflow
Describe external examination of the head for signs of paranasal sinus disease
- Lymph nodes e.g. submandibular
- Facial symmetry
- Nasal airflow
- +/- Percussion of sinuses (dull sound if there is fluid or a mass)
What are the diagnostic methods for paranasal sinus disease
- Endoscopy: Sinus drainage angle
- Radiography: Laterolateral, Dorsoventral
- Computed Tomography
- Sinoscopy: endoscope directly into the sinuses
What is the most common cause of primary sinusitis?
Previous URT infection
Streptococcus spp.
What are the 5 most common causes of secondary sinusitis?
- Dental disease
- Sinus cyst
- Progressive Ethmoid Haematoma
- Neoplasia
- Fungal sinusitis (rare)
What are the diagnostic methods for sinusitis, which is the gold standard?
- Endoscopy
- Radiography
- Computed tomography (GS)
Which diagnostic method allows visualisation of purulent material coming from the sinus drainage angle?
Endoscopy
What can be used for the initial treatment of primary sinusitis?
Antimicrobials
What are the considerations surrounding antimicrobial use?
- +/- Culture and sensitivity testing - Only to rule out Strep. Equi var equi infection (Strangles)
- One course of antibiotics ONLY: Trimethoprim sulphonamides for 7-14 days.
Poor response/recurrence indicates further
investigation required
Why should different antimicrobials not be tried?
- Promotes antimicrobial resistance (AMR)
- Will not resolve chronic infection with inspissated pus present or where there is a secondary cause of infection
- Adds unnecessary costs to clients bill (and may prevent them being able
to afford further diagnostics / treatment)
What are some other treatment methods for primary sinusitis?
- NSAID’s: e.g. phenylbutazone
- Feed from the ground: encourage drainage
- Dust free management: reduce URT inflammation
- Turn out as much as possible: drainage / reduced inflammation
Secondary sinusitis is most frequently due to…?
Dental disease
Approximately 60% of secondary sinusitis cases
Which teeth most commonly affect the rostral maxillary sinus?
Upper 08 / 09’s
Which teeth most commonly affect the caudal maxillary sinus?
Upper 10 / 11’s
Why can diagnosis of secondary sinusitis be difficult?
- Radiography insensitive (difficult to interpret radiographs in many cases)
- Computed Tomography is the gold standard (and may be more cost effective)
How can secondary sinusitis be treated?
- Removal of infected tooth
- Management of sinusitis
Describe paranasal sinus cysts and their effects/signs
- Young horses most common but can be seen in all ages
- Aetiology unknown
- Filled with yellow, viscous fluid
- Causes erosion and distortion as it expands -> Nasal passage deformity and facial swellings
What are the clinical signs of paranasal sinus cysts?
- Facial swelling
- Reduced nasal airflow (can be subtle to detect)
- Nasal discharge
- Nasal stertor
How are paranasal sinus cysts diagnosed?
Radiography
Sinoscopy
Computed tomography
How are paranasal sinus cysts treated?
Surgical removal via trephine portals / sinus flap
Describe diagnosis/signs of sinus neoplasia
• May not be detected until extensive growth of the mass has already occurred - Facial swelling - +/- nasal discharge, head shaking • Radiography / sinoscopy • Computed tomography
What are the 4 common types of sinus neoplasia
- SCC
- Adenocarcinoma
- Fibro-osseous tumors
- Myxoma
How are sinus neoplasia treated?
Usually too extensive to treat
Debulking and radiotherapy uncommonly performed (costs / facilities)
How is sinus trauma diagnosed and treated?
- Clinical signs
- Radiography
- +/- Ultrasound
- +/- Computed Tomography
• Removal / stabilisation of bone fragments
• Flushing of sinuses to remove any blood/purulent material
Where is the trephine site to access the frontal sinus?
60% from midline to medial canthus
0.5cm caudal to medial canthus
Can then access CMS, DCS, SP
Can access RMS/VCS if remove maxillary septal bulla
Where is the trephine site to access the caudal maxillary sinus?
2cm rostral and 2cm ventral to medial canthus
Describe sinus surgery to perform sinus flaps
- May need increased access into the sinuses for removal of masses/other treatment
- Often performed under standing sedation
- Rectangular / circular bony flap created
What are some of the potential complications when performing sinus surgery?
- Haemorrhage
- Infection of the trephine portal/sinus flap
- Bone sequestrum formation
- Poor cosmesis
- Recurrence of sinusitis
What is empyaema of the conchal bullae?
Chronic infection of the dorsal or ventral conchal bulla
What is suturitis and its signs?
- Periostitis of the suture lines
- Most common- frontonasal suture
- Can occur after sinus surgery
- Bilateral, firm, swellings in the nasofrontal region
- Usually regress
