Equine Dentistry and Diseases of the Head Flashcards
What can dental disease result in for horses?
- Oral pain and discomfort
- Weight loss
- Predisposition for certain colics
- Secondary disease process- sinusitis
What type of teeth do horses have?
Hypsodont- long crowned
Erupt 2mm/year
What is a horses deciduous and permanent dental formula?
Deciduous- [I 3/3, C 0/0, M 3/3] x2 = 24
Permanent- [I3/3, C1/1 or 0/0, PM 3/3 or 4/4, M3/3] x2 = 36-44
Which first number of 1, 2, 3 or 4 identifited which quadrant of a horse mouth with the triadan system?
100- upper right /5
200- upper left/ 6
300- lower left/ 7
400- lower right/ 8
/ deciduous
When do horses deciduous and permanent incisors erupt and show wear?
Deciduous Incisors-
Central- 1 week
Middle- 6 weeks
Corner- 6-9 months
Central permanent- 2.5 years, in wear 3 years
Middle permanent- 3.5 years, in wear 4 years
Corner permanent- 4.5 years, in wear 5 years
When do canines and wolf teeth erupt in horses?
Canine-
No deciduous precursor
Erupt- 5 years
Males- occasionally females
Wolf teeth-
No deciduous
Erupt- 1 year
When do horses premolars and molars erupt?
Premolars 06, 07 and 08 present at birth no deciduous molars
06- 2.5 years
07- 3.5 years
08- 4 years
09- 1 year
10- 2 years
11- 3.5 years
What anatomical differences can be identified on different age of horses?
The infundibulum
Secondary dentine
Amount and presence depends on age
What are each of the arrows pointing too?
How do maxillary and mandibular cheek teeth differ?
Arrows-
Top left- enamel
Top right- peripheral cementum
Bottom left- primary dentine
Bottom right- irregular secondary dentine/regular secondary dentine
Maxillary CT- 2 infundibulae, wide ‘square’
Mandibular CT- no infundibulae, narrow ‘rectangular’
What are pulp horns?
How many does each cheek tooth have at least, which have more?
Pulp horns are an area of pigmented secondary dentine on the occlusal surface, protects underlying pulp
Every cheek tooth have at least 5
06s- have extra rostrally
11s- extra 1-2 caudally
How many roots do maxillary/mandibular cheek teeth have?
Where are the roots found?
What happens if the teeth become infected?
Maxillary- 3 roots- 2 lateral, 1 palatal
Mandibular- 2- rostral and caudal
06, 07- root end in maxillary bone
08, 09- rostral maxillary sinus
10, 11- caudal maxillary sinus
Teeth infection- facial swelling/draining tracts, malodorous smell/ nasal discharge
What is anisognathia?
Differing upper and lower jaw width
Maxillary cheek teeth are further apart then mandibular
What are some normal anatomical variations of horses dentistry?
Curvature of the maxilla- widest 08-10
Implications- tack, removing buccal overgrowths
Curve of spee- more prononced in Arabs, care removing caudal 11 overgrowths
What is needed for a equine dental examination?
Appropriate area
+/- sedation
Dental equipment
Gloves
recording sheets
+/- head stand
What should be done in an initial examination of a horse?
- Thorough history- recent weight loss, colic
- Watch horse eat- normal sounds, both sides, time
- Clinical exam- underlying disease, swellings, halitosis, nasal discharge
What dental equipment is needed for oral examination?
Gag
Light source
Dental mirror
Dental syringe
Pulpar explorer
Periodontal probe
Diastema forceps
Rasps- motorised tools
What should be checked for on an incisor then canines and wolf examination?
Incisors- without gag
- Check for abnormal masses/ fractured teeth
- Check occlusion from side and front
- Count the teeth
Canines- calculus, fractures, apical infection
Wolf- displacment, blindly erupted, mandibular wolf
When palpating cheek teeth during a oral examination how should it be done?
What are you feeling for?
- Occlusal surface of every tooth
- Edges of teeth- buccal maxillary, lingual mandibular
- Every inter-dental space
- Buccal mucosa
- Tongue adjacent to teeth
- Dental overgrowths- sharp points, soft tissue trauma
- Diastemata
- Dental fractures
- Displacment
- Supernumary teeth
When doing a visual oral examination what should be done?
Look- wihout mirror-
Count, overgrowths, soft tissue trauma, fractures
Look with mirror-
count again, all surfaces, interdigital spaces
Probe- pulp horns, assess depth of diastemata
What does oral endoscopy allow?
What is routine floating?
Better evaluation of occlusal surface, diastema and periodontium
Hand rasping- 3-4 hand rasps, full examinatino, sedation
What further diagnostic imaging can be used for equine dentistry?
Radiograph
Sinoscope
Computed tomography
Schintigraphy
MRI
What are the two equine dental paraprofessionals and what is the difference?
BAEDT- passed BEVA exam, CAT 1 and 2 procedures
Others- Attended a course but not examined- only CAT 1
What are CAT 1 procecures?
- Examinations
- Removal or sharp points with manual rasps
- Removal of small dental overgrowths- manual rasps
- Rostral profiling of first cheek teeth
- Removal of loose deciduous caps
- Removal of supragingival calculuc
What are CAT 2 procedures?
- Examinatino, evaluation and recording of dental abnormalities
- Removal of loose teeth/fragments- negligible periodontal attachments
- Removal of erupted, non-displaced wolf teeth under vet supervision
- Palliative rasping of fractures and adjacent teeth
- Motorised dental insturments to reduce overgrowths and sharp enamel points only
- Horses sedated unless safe without, consent from owner
Who can perform category 3 procedures?
Qualified veterinary surgeons
Diastemata widening
Unerrupted wolf tooth removal
What is the consequence of brachygnathism and prognathism in horses?
Brachygnathism-
Ulceration behind upper incisors
Maxillary rostral 06 overgrowths and mandibular 11 overgrowths which will need lifelong attention
Prognathism-
Fewer incisor problems, overgrowths of lower 06 and upper 11 overgrowths
What is campylorrhinus lateralis?
‘wry nose’
Deviation of the entire maxilla, invilving incisive region, nasal septum and nasal bones
Varying degree of severity- from minor occlusal problems to severe and breathing problems
Surgical correction can be attempted but complex
What is malocclusion secondary to?
What is slant mouth?
Secondary to problems involving the cheek teeth
Slant mouth or diagonal bite is indicative that the horse is eating predominantely one one side
1) How does retained deciduous teeth in horses ususally present?
2) How is it treated?
3) What is done with supernumerary incisors?
1) Usually rostral to permanent tooth
2) Treatment- loose: remove with forceps, firmly attached: remove with dental elevators
3) usually cause little problem, often best not to remove
What can cause incisor fractures?
What indicates extraction?
Trauma, caught on objects, cribbiting
Determine if pulp affected- extraction required
What is incisor diastemata?
What is valve diastemata?
What should be done?
Spaces between adjacent teeth
Valve- narrower at occlusal aspect, wider at gingival margin, traps food near gingiva
Food should be removed from the spaces with a toothbrush on a twice weekly basis
What is Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH)?
How is it managed?
Swelling and/or draining tracts over multiple mandibular and maxillary incisors- pain
Diagnosis- visual, radiograpy
Extraction of the loose incisiors is curative
Disease is progressive in some cases spreading from tooth to tooth
May have to remove incisors- horses cope well
How is equine oral neoplasia classified?
According to the tissue of origin
Dental
Bone
Soft tissue
According to behaviour- benign/malignant
What oral neoplasias are from dental tissue origin?
Ameloblastoma- older horses, mandibles, causes bony swelling
Benign- surgical excision
Cementoma
Odontoma
Temporal teratoma
What equine oral neoplasias are of soft tissue origin?
Squamous cell carcinoma
Sarcoid
Epulis
Melanoma
Oral papilloma
Ossifying fibroma
Fibroma
Myxoma/myxosarcoma
What canine abnormalities can affect horses?
Rarely cause problems
Calculus around lower canines most common- remove with dental forceps, owner can clean periodontal pockets
Apical infection/fracture- endodontic treatment, removal can be challenging- long and curved roots
Why are wolf teeth commonly removed?
When is removal indicated?
Due to owner/trainer preference/tradition
Do not cause problems with normal shape, position- is removal justified?
Indications- biting problems/ulceration, blindly erupted
May become molarised- look like a molar, always radiograph
What is used for wolf teeth removal?
What are the potential complications?
- Specialised kits do exist, alternatively a long handled elevator or small animal tooth luxator and forcep
- Standing sedation and speculum
- Local anaesthesia- infra-orbital/maxillary
- Blindly erupted- incise gingiva over top with no 11/15 scalpel
- Remove once loose with forceps
- 2 weeks bit rest
Complications:
Fracture of tooth
Fracture of bone
Trauma to palatine artery
When should dental checks be done for horses?
Ideally examine cheek teeth briefly in first week- check for cleft palate
Yearly checks as the cheek teeth begin to erupt
The earlier you begin working on a horses mouth the more tolerant it will be
It is usuaul to have to perform any routine rasping before 2 yo
What are retained caps?
Remnants of deciduous teeth- normally shed during eruption
Loose/retained caps can cause oral pain
Usually attached to gingiva in one place- causes pain
Easily removed with forceps
What can cause cheek teeth displacments?
What problems can it lead to
Overcrowding during eruption- often bilateral
Can lead to rotation and trauma
Diastemata can lead to periodontal disease
What is developmental diastemata?
What can it lead to?
Opposing angulation causes the compression of occlusal sufaces of the teeth together in rostro-caudal direction- should
If this doesnt haeppen teeth develop too far appart
Leads to-
Spaces developing
Food accumulating
Fermentation
Periodontal disease
What is done if there is a supernumerary cheek tooth?
May result in periodontal disease- extraction indicated
If they occlude normally with the other teeth can be left in situ but may require regular rasping
What causes enamel overgrowths and where are they found?
When are they more pronounced?
What can exacerbate the problem?
What are the clinical signs?
How are they managed?
Anisognathism- leads to enamel points- buccal of upper, lingual of lower
More pronounced where horses fed more concentrated
Tack can exacerbate the problem
Clinical signs- quidding, pain when eating
Rasp on routine dental
What are some disorders of wear?
When are they more commonly seen?
Wavemouth- marked undulation to occlusal surface, dominant areas can be sequentially reduced
Strepmouth- may occur when a focal overgrowth occurs, can be reduced in stages
More commonly seen in horses without regular dental care
What is shear mouth?
What causes it?
How is it managed?
Increased occlusal angle of entire cheek tooth row
Usually secondary ro diastemata formation/dental fracture
If bilateral suspect temporomandibular joint arthropathy
Managment-
Treat primary problem
Gradual reduction of the angle
What does this image show?
What is done to treat this?
Exaggerated transverse ridges- large overgrowth
Hand or power rasp in stages
Excessive can lead to pulp exposure, thermal damage and risk apical infection
High risk sites- rostral 06 and caudal 11s
What is ‘bit seating’
Rostral profiling- to prevent bit impingment- misconception
Uneccessary can cause pulp horn exposure
What are dental caries when does it occur?
Caries can affect the peripheral cementum of the maxillary and mandibular cheek teeth and the infundibulae of the maxillary cheek teeth
Occurs when food material becomes stagnated in pits in the peripheral cementum:
Fermentation, drop in pH of the environment, demineralisation, pits bigger and blackening
Cementum becomes eroded first, may spread to peripheral enamel
What are the two types of caries in horses?
What causes them?
How can they be managed?
Infundibular caries
- Common- grade 1-4
- Developmental predisposition- cemental hypoplasia, food acumulated in infundibulum, fermentation- decay
- Progressive, irriversible, predisposes to fracture
- Can be managed with infundibular restoration
Peripheral caries
- Common
- Increased sugars- haylage
- Managment- palliative rasping of the roughened cementum, removal of excess sugars
How does diastemata treatment vary?
Depends on severity of periodontal disease
Without PD
Cleaned out completelt- pick then lavage
Remove ETRs on opposite arcade
Pack with impression material
With PD
Widen with burr- lidocaine
Pack with impression material
Dietary managment- short fibre
What are the three main types of cheek teeth fractures?
Buccal slab
Midline saggital- through infundibulum
Occlusal fissure
What is smooth mouth?
Senile change- cheek teeth and enamel largely worn away
Softer dentine and cementum become smooth
Dietary manage- feedings chopped forage
How does the presentation of buccal slab fractures vary?
May be incidental
Quidding behaviour- slab can damage gingiva
Usually not associated with apical infection, pulp horn seals off, extraction may be required
What teeth most commonly have midline sagittal fractures?
What can it result in?
Most common 109 and 209
Pathologoical fracture through infundibulum
Results in apical infection- with or without sinusitis, extraction required
What do the clinical signs of an apical infection depend on?
Give examples
Depends on which teeth are involved
Location in relation to paranasal sinuses
Facial swelling +/- draining tract- Maxillary 06, 07, occasionally 8
Unilateral nasal discharge- maxillary 09, 10, 11
Bony mandibular swelling- all mandibular cheek teeth
What are the causes of apical infections?
What is the pathogenesis?
Causes-
Anachoresis
Fracture
Periodontal spread
Pulpar exposure
Path-
Pulpitis- pulpar oedema, vascular occlusion, necrosis
How is apical infection diagnosed?
Clinical signs
Oral examination- fracture, pulpar exposure
Imaging-
radiograph- poor sensitivity
CT- gold standard
What are the methods of cheek tooth extraction?
Oral extraction
Modified transbuccal extraction
Lateral buccotomy
Repulsion
What are the steps to oral teeth extraction?
- Interdental spreading- placed in the interdental space infront and behind, closed gradually to stretch peridontal ligament- can cause further fracture
- Molar forcep application- wiggling- lateral strain- different types
- Apply fulcrum- lever the tooth out
What instrument are these?
Interdental spreaders
What are these instruments?
Molar forceps
Different depending on the tooth shape
When is minimially invasive transbuccal extraction indicated?
Used when crown fractures
specialist equipment
Chisels to breakdown ligament, reserve crown drilles, hole tapped, extraction screw inserted
Preserves alveolar bone
What is repulsion?
Blunt instrument to drive tooth into mouth
High potential for complications
What is lateral buccotomy?
Incision through cheek, removal of lateral alveolar bone
Often GA
Potential damage to facial nerve and parotid duct
High morbidity rate- iatrogenic trauma, wound breakdown
What are the 7 functions of the URT in a horse?
- Conduit- air to and from lung
- Filtering- mucus
- Protection
- Olfaction
- Phonation- vocalising
- Swallowing
- Thermoregulation
At rest what is the normal respiratory rate, tidal volume and therefore minute ventilation of a 500kg horse?
What is the increase of minute ventilation at excercise?
How is it coupled with gait?
At rest- 15 breaths per minute
1L per 100kg- 5L
Minute ventilation- 75L
Excercise- 20x increase- 1500L
Coupled with gait at when FL hit the ground pressure from abdominal organs moving forwards helps breath out, HL hit ground and abdomen pressure backwards, breath in
Why is URT function very important in horses?
Horses cannot switch to mouth breathing
Anything that narrows airway of lumen- increases airflow resistance, increases negative pressure, causes unsuported structure collapse, URT obstruction leading to noise and reduced O2 delivery
URT disease is common and can be life threatening and cause poor performance
What are the clinical signs of URT disease?
- Respiratory noise/distress
- Dysphagia
- Coughing
- Excercise intollerance
- Nasal discharge- blood, purulent material, ingesta
- Facial deformity
- Neurological signs
What histrory should be taken from a horse with suspected URT disease?
General- signalment, use, duration of ownership, general health, duration, managment, dental prophylaxis, any other horses, eating/drinking
Specific-
- Nasal discharge
- Respiratory noise
- Excercise intollerance
- Cough
- Bilateral nasal airflow
- Previous medical treatment
What should be noted about a nasal discharge?
Bilateral- behind nasal septum- guttural pouch, larynx, pharynx
Unilateral- rostral to nasal septum- sinus/nasal passage
Duration
Nature- serous, blood, putulent, food
Evidence of trauma
What history of respiratory noise should be obtained?
- Severity of obstruction- noise
- When- rest, excercise
- Inspiratory/Expiratory
- What does the noise sound like- whistle, roar, gurgle, snoring
- Continuous/intermittent
- Performance effects- does the horse stop/slow
How is the respiratory system examined at rest?
Look, listen palpate
General physical examination- all systems, concurrent disease, RR and character, Nostril flare, Auscultation of thorax/trachea, rebreating- bag over heat
Assess other causes of poor performance- lameness, cardiac disease
What should be examined about a horses head?
Symmetry
Nasal/occular discharge
Airflow from both nostrils
Percussion of sinuses
Palpation of larynx
Previous surgical scars
What noises at excercise are normal?
What should be noted about abnormal sounds?
Snorting, ‘high blowing’, Sheath noise, Thick wind
When- throughout/pushed/tired
Quality/pitch
Stride phase
What diagnostic imaging can be used for the head?
- Endoscopy
- Radiography
- Sinoscopy
- CT
- Ultrasonography
- MRI
- Scintigraphy- less so
- Sound analysis- spectral analysis
What are the advantages of resting endscopy for URT disease?
When is it indicated?
Widely available, affordable
Minimally invasive
Directly visualise regions
Options for treatment- laser removal or fenestration
Indications-
Nasal discharge/malodour
Respiratory noise
Dysphagia
Why is excercising endoscopy useful?
What can be identified here that cannot be elsewhere?
What are the advantages of dynamic respiratory endoscopy?
Important for assessment of poor performance at excercise- more accurate assessment of dynamic airway function at excercise
Many cases of URT obstruction only occur at excercise and can only be identified here
DRE- Affordable and widespread, unqique design, attaches to bridle, wireless pictures, real time examination
What is head radiography traditionally the gold standard for?
What are its Adv and Dis?
What are the standard and additional radiographic views?
Traditionally the gold standard for assessing bony/dental structures
Adv- Images can be obtained with portable machines, easy to perform standard views
Dis- complex anatomy, 2D image
Standard- Latero-lateral, Lateral-oblique, Dorso-ventral
Additional- Intra-oral, open mouth oblique, tangenital views
What are the following views useful for assessing?:
Latero- lateral view
Lateral oblique
Dorso-ventral
Intra-oral
Latero-lateral- good for assessing paranasal sinused, guttural pouches, pharynx. Cassette on affected side
Lateral- oblique- assess the periapical regions of cheek teeth for evidence of infection. 30 degree angulation maxillary arcades, 45 degree angulation mandibular arcades
Dorso-ventral- assessment of paranasal sinuses, nasal septum and teeth. Helps to determine if lesions uni/bilateral
Intra-oral- assessment of incisor teeth and associate bone, fractures of incisor teeth/associated bone EORTH
How we doing big man?
This seems useful to have a general look at but doesn’t seem worrying about
Keep it up.
Remember be the best person you can.
What are the Adv and Dis to sinoscopy?
Adv- minimally invasive means of visualizing the paranasal sinuses, enables surgical treatmenr and ongoing monitoring of sinuses
Dis- more invasive than routine endoscopy- standing sedation with local
What limits head ultrasonography?
What are some important uses?
Bony skill limits its use in assessment of some areas of the head
Some important uses:
- Opthalmic
- Soft tissue swellings
- Assessment of skull bones
- Larynx
What are the advantages of CT?
When is it indicated?
- Gold standard
- Affordable and cost effective- not sure personally
- Cross sectional images, superior resolution, tissue density measurement
Indications-
- Dental disease
- Masses withing paranasal sinuses/ nasal passages
- Trauma
What are the two CT sytems used for horses?
What are the advantages of each?
How is CT interpretated?
GA- less movement from patient (better images)
Standing sedation- avoids GA, stabilise patient prior to surgery, pre-surgical planning
Using hounsfield unit tissues have different values (density)- higher density higher number- enamel, bone… air
Why are equine head MRIs rarely performed?
Limited to only a few facilities
Requires GA
Expensive
Time
Uncommonly indicates- brain lesions, neoplasia
What are the indications for scintigraphy?
What has superseded it?
Indications-
differentiation between primary/secondary sinusitis
Identification of correct tooth
Suspected TMJ disease
Superseded by CT
- What does the soft palate separate?
- What allows pharyngeal collapse?
- What are the 3 functions of the pharynx?
- Nasopharynx and oropharynx
- Lacks rigid support by bone/cartilage
- Passage of air- to larynx and lower airways
Passage of ingesta- oral cavity to oesophagus during swallowing
Airway protection
Describe the anatomy of the pharynx
- Muscular tube
- Relient on neuromuscular function for stability
- Intrinsic/extrinsic musculature
- Innervation- cranial nerves V, X, XI and cervical nerves
V- trigeminal
X- Vagus
XI- accessory
- What are the main functions of the larynx?
- What cartilage structures are associated?
- When does abduction take place, muscle-insertion and innervation?
- When does adduction take place, muscle- insertion and innervation?
- Breathing, protect LRT, vocalisation
- Cricoid cartilage, thyroid cartilage, epiglottis, paired arytenoid cartilages
- Excercise, cricoidarytenoideus dorsalis muscle (CAD), cricoid cartilage to arytenoid cartilage, recurrent laryngeal nerve
- Closure- swallowing, cricoarytenoideus lateralis muscle (CAL), RLN innervation
- What are the key presenting signs of larynx/pharnx disease?
- What should be clinically examined
- Respiratory noise, excercise intolerance, poor performance
- Palpation of the larynx- muscular process of arytenoid, cricothyroid articulation
Observation during excercise
What imaging modalities can be used for diagnosis of larynx and pharynx disease?
- Endocsopy- rest, excercsie
- Ultrasound
- Radiography
- CT
- MRI
What are the clinical signs of pharynx disease?
List the key disorders?
Clinical signs- poor performance, respiratory noise, dysphagia, respiratory distress, nasal discharge, coughing
Key disorders-
DDSP- intermittent, persistent
Naso-pharyngeal collapse
Pharyngeal lymphoid hyperplasia
Cleft palate
Foreign body
Pharyngeal mass
What is iDDSP and persistent DDSP?
Intermittent dorsal displacment of the soft palate
Dynamic condition- during intense excercise
Soft palate displaces- expiratory obstruction, gurgling
Returns to normal on swallowing
Persistent DDSP-
Soft palate permanently displaced
Often secondary- epiglottic entrapment, sub-epiglottic ulcer/cyst
May have dysphagia
What is the proposed pathogenesis of iDDSP?
Neuromuscular dysfunction
Thyroideus muscle pulls larynx forward into pharynx
Innervated by pharyngeal brach of vagus
Maybe caused by inflammation in guttural pouch or pharnx
Lower airway disease
Structural abnormalities
How is DDSP diagnosed?
History and Clinical examination
- Excercise intolerance
- Gurgling
- Rider reports
- Dysphagia- permanent
Endoscopy
- Resting- assess structural abnormalities, diagnostic pDDSP
- Excercising- gold standard, replicate conditions when disease occurs
How can DDSP be treated?
iDDSP- conservative:
Maturity- common in youngsters
Get fit- muscles that support pharynx
Change tack- keep mouth closed
Tongue tie- stop caudal movement
Treat inflammation
Throat support- cornell collar
Surgical-
Tie forwards- sutures between basihyoid and thryoid cartilage
Palatoplasty- thermal/laser or stiffen
Staphylectomy- questionable
Myectomy- rarely performed
What is pharyngeal lymphoid hyperplasia?
When is it common?
Enlargment of lymphoid follicles on the walls and roof of nasopharynx
Common in young horses
little clinical significance
What are the two types of nasopharyngeal collapse?
Nasopharyngeal dysfunction-
Neonates- dysphagia
Self-resolves
Dynamic pharyngeal collapse
Lateral or dorsal walls
Yearlings/2 yo- +/- other disease
Sport horses- exacerbated by neck flexion
What is cleft palate?
What are its DDXs?
How is it diagnosed and treated?
Congenital defect
DDXs- pharyngeal dysfunction, guttural pouch tymphany
Diagnosis- oral examination/endoscopy
Surgical repair often not attempted
What are the clinical signs of larynx disorders?
List the laryngeal disorders
Respiratory noise, Poor performance, Dysphagia, Coughing, Respiratory distress
- Recurrent laryngeal neuropathy
- Fourth branchial arch defect
- Dynamic laryngeal disorders
- Arytenoid chronditis
- Epiglottic abnormalities
What is recurrent laryngeal neuropathy?
Describe the pathophysiology
How is it diagnosed?
Left unilateral paresis/paralysis of the arytenoid cartilage
Pathophysiology- progressive loss of large myelinated nerve fibres of recurrent laryngeal nerve, neurogenic atrophy of intrinsic laryngeal muscles, loss of adduction/abduction
Diagnosis
History- abnormal inspiration noise at excercising, poort performance
Atrophy of CAD on palpation
Endoscopy
When doing endoscopy for RLN what is assessed?
How is it graded?
How is it managed?
Gold standard- avoid sedation
Assessment- symmetry, synchrony, maintenance of abduction
Different grading systems-
Resting function- Havermeyer I-IV
Dynamic function- Havermeyer A, B or C
Managment depends on- findings, use of horse, age, degree, owner expectations, economic
- Prosthetic laryngoplasty- standing/GA- ‘tie back’
- Ventriculo-cordectomy
- Laryngeal re-innervation- nerve graft
- Arytenoidectomy
What are the DDXs of laryngeal paralyis?
Unilateral-
Perivascular injection
Guttural pouch mycosis
Previous surgery
Bilateral-
Hepatic disease
Toxicity- organophosphate, lead
Post anaesthetic
Equine protoxoal myeloencephalitis- not UK
What can cause laryngeal dysplasia?
Congenital- abnormal development of laryngeal cartilages
Laryngeal dysfunction- limited right arytenoid abduction, rostral displacement of palatopharyngeal arch, cricopharngeus muscle affected
What can detect vocal cord collapse?
How does it present?
How is it treated?
Only detected by overground scope
Inspiratory whistle- produces lots of noise
Treatment- vocalcordectomy
What is medial deviation of aryepiglottic folds?
How does is present?
What is it associated with?
How is it treated?
Collapse of the aryepiglottic folds
Inspiratory, thick noise
Associated with DDSP
Treatment- laser resection of folds
What is epiglottic entrapment?
What are the clinical signs?
How is it diagnosed and treated?
Loose sub epiglottic tissue wraps over and entraps epiglottic cartilage- intermittent or persistent
Prevents normal function
Clinical signs- respiratory noise, coughing during eating, sometimes poor performance
Diagnosis- endoscopy
Treatment- laser resection
What causes sub-epiglottic cysts?
What are the clinical signs?
Diagnosis and treatment?
Likely congenital
Clinical signs- respiratory noise, dysphagia, excercise intolerance
Diagnosis- endoscope
Treatment- laser or snare excision
What is arytenoid chondritis?
What are the clinical signs?
How is it diagnosed and treated?
Inflammation/infection of arytenoid cartilage- mucosal ulceration, progressive and painful
Clinical signs- respiratory noise/obstruction, respiratory distress
Diagnosis- endoscope
Treatment-
topical and systemic AB
Patrial resectoin
Aryenoidectomy
Permanent tracheostomy
