PATHOLOGY - Small Animal Upper Respiratory Disease Flashcards
What is stridor?
Stridor is a harsh, high pitched sound heart on inspiration which will resolve at rest/sleeping and worsen an exercise and excitement
What is indicated by stridor?
Stridor indicates upper airway obstruction and laryngeal paralysis
What is laryngeal paralysis?
Laryngeal paralysis is when their is failure of the dorsal cricoarytenoid muscle resulting in the glottis being unable to abduct during inhalation
What are the four clinical signs of laryngeal paralysis?
Stridor
Dysphonia
Gagging and coughing when eating and drinking
Exercise intolerance
What are the four clinical signs of an acute crisis of laryngeal paralysis?
Severe dyspnoea
Stridor
Cyanosis
Collapse
Which can trigger an acute crisis of laryngeal paralysis?
Excitement
Heat
Stress
Exercise
How do you diagnose laryngeal paralysis?
You diagnose laryngeal paralysis by visualising the larynx as the patient is recovering from anaesthesia. You cannot diagnose this while the patient in under anaesthesia, as all anaesthetic drugs will supress laryngeal function which could result in a false positive
How do you treat and manage an acute crisis of laryngeal paralysis?
Oxygen supplementation
Sedation
Steroids
Cooling
What should you do if your patient is not improving following supportive care for an acute crisis of laryngeal paralysis?
If your patient is not improving, consider surgical intervention or do an emergency tracheostomy
Have a conversation with the owner about this, and be aware that the surgery is very risky and can affect quality of life - especially as these tend to be older dogs
Which two surgical procedures can be done to treat laryngeal paralysis?
Cricoarytenoid lateralisation (tieback) surgery
Partial arytenoidectomy
What lifestyle changes have to be made following surgical correction of a laryngeal paralysis?
- Animals should be encouraged to eat slowly and drink only water, as there is a high risk of aspiration pneumonia
- Animals will not be allowed to swim as there is a high risk of aspiration pneumonia
- Use a harness rather than a lead and collar
What are the three main causes of laryngeal paralysis?
Idiopathic
Congenital
Secondary to other diseases
What signalement is prone to idiopathic laryngeal paralysis?
Old, medium to large breed dogs
Which dog breed is predisposed to laryngeal paralysis?
Labrador Retreivers
List six factors which can cause secondary laryngeal paralysis
Damage to the recurrent laryngeal nerve
Trauma
Myopathy
Neuropathy
Neoplasia
Hypothyroidism
Which surgical procedure can cause damage to the recurrent laryngeal nerve and subsequent laryngeal paralysis?
Thyroidectomy
What is stertor?
Stertor low pitch, snoring sound that worsens during excitement and sleeping
What is indicated by stertor?
Brachycephalic airway obstruction syndrome (BOAS)
What are the primary anatomical components of brachycephalic airway obstruction syndrome (BOAS)?
Stenotic nares
Elongated soft palate
Excess pharyngeal mucosa
Aberrant turbinates
Hypoplastic trachea
What are aberrant turbinates?
Aberrant turbinates are structural defromaties where the nasal turbinates extend beyond their normal anatomical limits
In which brachycephalic breed are hypoplastic tracheas more commonly seen?
Bulldogs
In which brachycephalic breed are aberrant turbinates more commonly seen?
Pugs
Which secondary conditions are seen as a result of brachycephalic airway obstruction syndrome (BOAS)?
Everted laryngeal saccules
Tonsillar hyperplasia and eversion
Laryngeal collapse
Regurgitation
Hiatal hernia
What is a hiatal hernia?
A hiatal hernia is when part of the stomach herniates into the thorax
What are the main consequences of brachycephalic airway obstruction syndrome (BOAS) that influence day to day life?
Inflammation and soft tissue thickening
Increased respiratory effort
Stertor
Regurgitation and aspiration
Exercise intolerance
Dyspnoea
Cyanosis
Heat intolarance
Collapse
Risk of death
How does brachycephalic airway obstruction syndrome (BOAS) cause inflammation and soft tissue thickening?
Brachycephalic airway obstruction syndome (BOAS) results in turbulent airflow due to the anatomical abnormalities. This turbulent airflow causes inflammtion and subsequent soft tissue thickening which will worsen the airway obstruction and turbulent airflow
How does brachycephalic airway obstruction syndrome (BOAS) cause heat intolerance?
The nasal cavity plays a central role in an animal’s ability to regulate their temperature, in animals with brachycephalic airway obstruction syndrome (BOAS), their nasal cavity is obstructed and thus they are unable to carry out adequate heat exchange. These animals will thus be heat intolerant, which will increase their oxygen demand and worsen their condition
Why does brachycephalic airway obstruction syndrome (BOAS) increase the risk of aspiration?
Brachycephalic airway obstruction syndrome (BOAS) increases regurgitation which will increase the risk of aspiration and thus aspiration pneumonia
What is the key clinical sign of an acute episode of brachycephalic airway obstruction syndrome (BOAS)?
Severe dyspnoea
How do you manage an acute episode of brachycephalic airway obstruction syndrome (BOAS)?
Oxygen supplementation
Sedation
Cooling
Administer steroids
What method of oxygen supplementation should you use for acute episodes of brachycephalic airway obstruction syndrome (BOAS), and why?
Flow-by oxygen is the best method as it is the least stressful for your patient so you reduce the risk of stressing the patient out and worsening their dyspnoea
Which sedative is recommended for patients suffering from an acute episode of brachycephalic airway obstruction syndrome (BOAS)?
Butorphanol
Why should you administer steroids to patients suffering from an acute episode of brachycephalic airway obstruction syndrome (BOAS)?
Steroids should be administered as brachycephalic airway obstruction syndrome (BOAS) causes inflammation and soft tissue thickening and steroids reduce inflammation
Which steroid should you use in an acute episode of brachycephalic airway obstruction syndrome (BOAS)?
IV or IM Dexamethasone
What should you do if your patient is not improving following supportive care for acute brachycephalic airway obstruction syndrome (BOAS)?
If your patient is not improving, consider putting them under anaesthesia and intubating them, or do an emergency tracheostomy
Have a conversation with the owner about this, and be aware there is a chance the animal may not recover from anaesthesia
What advice should you give to owners to manage brachycephalic airway obstruction syndrome (BOAS)?
Weight loss
Use a harness rather than a lead and collar
Short walks in the morning and/or evening (when it is cooler)
Minimise stressors
Consider surgical intervention
What are stenotic nares?
Stenotic nares are caused by the collapse of the dorsolateral cartilages after birth
Which surgical intervention can be done to correct stenotic nares?
Wedge resection
At what age can you do a wedge resection?
You can do a wedge resection from 3 to 6 months old
How do you diagnose an elongated soft palate?
You diagnose an elongated soft palate by visualising the soft palate under anaesthesia
Which surgical intervention can be done to correct an elongated soft palate?
Soft palate resection
What are the landmarks for diagnosing an elongated soft palate?
If the soft palate extends beyond the caudal poles of the tonsils, it is an elongated soft palate
How does brachycephalic obstructed airway syndome (BOAS) cause eversion of the laryngeal saccules?
Brachycephalic obstructed airway syndrome (BOAS) causes an increased respiratory effory which will generate a negative pressure which will evert the laryngeal saccules
Which surgical intervention can be done to correct laryngeal saccule eversion?
The laryngeal saccules can be removed however this is not always done
How does brachycephalic obstructed airway syndome (BOAS) cause laryngeal collapse?
Brachycephalic obstructed airway syndrome (BOAS) causes an increased respiratory effory which will generate a negative pressure which can cause laryngeal collapse
Which two surgical procedures can be done to correct laryngeal collapse?
Cricoarytenoid lateralisation (tieback) surgery
Partial arytenoidectomy
What are feline polyps?
Feline polyps are benign inflammatory growths of connective tissue that arise from the mucosal lining of the tympanic bulla and extend into the external ear canal - known as an aural polyp - or extend into the nasopharynx - known as a nasopharyngeal polyp
What are the clinical signs of nasopharyngeal polyps?
Stertor
Dysphagia
Unilateral nasal discharge
Which surgical procedure can be done to correct nasopharyngeal polyps?
Traction evulsion
What are some of the risks of traction evulsions of feline polyps?
Horner’s syndome
Vestibular disease
What sugical procedure may be required if feline polyps recur after traction evulsion?
Ventral bulla osteotomy
This is referral surgery
Which ten questions can be useful to ask when gathering a history when an animal presents with nasal discharge?
Has this nasal discharge been acute or chronic?
Is the nasal discharge uni- or bilateral?
What is the nature of the discharge?
Has your pet been sneezing or reverse sneezing?
Has your pet been coughing?
Has there been any head shyness or reluctance to eat?
Has your pet been pawing at or rubbing their face on the ground?
Is there a history of dental disease?
Has there been any trauma?
Vaccinations/worming?
Any recent travel?
When is nasal discharge classified as acute or chronic?
Nasal discharge is acute is it has been going on for less than three weeks, and it is chronic if it has been going on for more than three weeks
What is indicated by acute nasal discharge?
Foreign body
Infection
What is indicated by chronic nasal discharge?
Fungal disease
Neoplasia
Chronic infection
What is indicated by unilateral nasal discharge in small animals?
Foreign body
Polyp
Tooth root abscesses
Fungal disease
Neoplasia
i.e. more localised disease
What is indicated by bilateral nasal discharge in small animals?
Systemic disease
Infectious disease
Progressive fungal disease
Progressive neoplasia
What are the six different forms of nasal discharge?
Serous
Mucoid
Purulent
Sanguineous
Epistaxis
Food containing discharge
What is this form of nasal dischage?
Serous nasal discharge
What are the four main differentials for serous discharge?
Normal
Viral infection
Non-infectious inflammatory disease
Early signs of an aetiology that will progress to mucopurulent discharge
Which species more commonly experience serous discharge due to viral infections?
Cats
What is this form of nasal discharge?
Mucoid nasal discharge
What is the form of this nasal discharge?
Purulent nasal discharge
What are the differentials for mucopurulent nasal discharge?
Mucopurulent nasal discharge is non-specific and can occur with any causes of inflammation as well as diseases of the lower airways
List five examples of diseases which can cause mucopurulent discharge
Infection
Neoplasia
Foreign bodies
Polyps
Bronchopneumonia
What is this form of nasal discharge?
Epistaxis
What are the differentials for epistaxis?
Epistaxis is non-specific and can be indicative of local and systemic disease
What are three local causes of epistaxis?
Neoplasia
Fungal disease
Acute trauma
Which other type of nasal discharge does fungal disease commonly present with in addition to epistaxis?
Mucopurulent discharge
What is the main systemic cause of epistaxis?
Haemostatic disorders
Which investigative tests should you always do if a patient presents with epistaxis?
Platelet count
Buccal mucosal bleeding time
Prothombin time (PT)
Activated partial thromboplastin time (aPTT)
What are the two main differentials for food containing nasal discharge in young animals?
Cleft palate
Dysphagic condition
What is the main differential for food containing nasal discharge in older animals?
Oronasal fistula
(T/F) Reverse sneezing is generally harmless
TRUE. Owners will often be very alarmed but generally reverse sneezing is harmless. However, prolonged reverse sneezing can indicate there is chronic nasal disease
What should you assess during a clinical exam of an animal with nasal discharge?
- General clinical examination
- Assess facial symmetry
- Assess for facial pain
- Assess for exopthalmos, third eyelid protrusion and inability to retropulse the eye
- Characterise the nasal discharge
- Assess for oral, rhinarium and ocular ulceration
- Assess for crusting or depigmentation of the rhinarium
- Intraoral exam to assess for dental disease, holes, massess or halitosis
- Assess for airflow at the nostrils
- Assess for signs of haemostatic disorders if indicated
What is halitosis?
Halitosis means bad smelling breath
Which investigative tests can you do for patients presenting with nasal discharge?
Radiography
CT/MRI
Rhinoscopy
Nasal biopsy
Nasal flush
Nasal swabs
What are the main limitations of radiography for investigating nasal discharge?
Superimposition of nasal structures
Poor definition of soft tissue changes
Inability to distinguish between soft tissue and fluid
What are the key signs of pathology on radiographs of the nasal cavity?
Loss of nasal turbinate pattern
Increased soft tissue/fluid opacity
Increased radio-lucency
Bony destruction
Extra-nasal changes
(T/F) Radiography of the nasal cavity requires general anaesthetic
TRUE.
What are the basic radiograph views that should be used to investigate nasal discharge?
Dorsoventral intra-oral
Left lateral oblique
Right lateral oblique
What is the main advantage of a dorsoventral intra-oral radiograph view?
A dorsoventral intra-oral radiograph view allows for assessment of the nasal cavity without superimposition of the mandible
What is the main advantage of lateral oblique radiograph views?
A lateral oblique radiograph view seperates the two sides of the skull for assessment
Which additional radiograph views can sometimes be done to investigate nasal discharge?
Open mouth ventrodorsal
Rostrocaudal
What is the main advantage of an open mouth ventrodorsal radiograph view?
An open mouth ventrodorsal radiograph view allows for the assessment of more caudal structures (such as the cribriform plate)
What is the main advantage of a rostrocaudal radiograph view?
A rostrocaudal radiograph view allows you to assess the frontal sinuses
What are the advantages of using CT/MRI to investigate nasal discharge?
CT/MRI are more accurate than other forms of imaging
What is the main disadvantage of using CT/MRI to investigate nasal discharge?
CT/MRI is expensive and less readily available
What are the two methods that can be used to do a nasal biopsy?
Rhinoscope directed nasal biopsy
Blind biopsy
Which landmarks should you use to avoid penetrating the cribriform plate when doing a blind nasal biopsy?
Measure the grab biopsy tool from the nose to the medial canthus of the eye and don’t advance the grab biopsy tool beyond that point
Why should patients preferably stay in the practice overnight following a nasal biopsy?
Nasal biopsies can result in a lot of bleeding which can be distressing for owners and it is important to monitor the patients
What further investiagtion can be done on a nasal biopsy?
Histopathology
Cytology
Culture
What can a nasal flush be used for?
Sampling for cytology
Dislodge a foreign body
What can nasal swabs be used for?
Cytology
Culture
What is the typical clinical presentation of cat flu?
Acute onset
Bilateral nasal discharge
Serous to mucopurulent nasal discharge
Sneezing
± Ocular discharge
± Ocular ulceration
(T/F) Primary bacterial rhinitis is more common than secondary bacterial rhinitis
FALSE. Primary bacterial rhinitis is rare whereas secondary bacterial rhinitis is more common
Which two pathogens cause primary bacterial rhinitis?
Bordetella bronchiseptica
Mycoplasma
What is secondary bacterial rhinitis?
Secondary bacterial rhinitis is the overgrowth of commensal bacteria secondary to an underlying disease
Which antibiotic can be used to treat bacterial rhinitis?
Doxycycline
What is the typical clinical presentation of a nasal foreign body?
Acute onset
Unilateral nasal discharge
Sneezing
± Pawing at or rubbing their face on the ground
± Facial pain
± Epistaxis
± Mucopurulent nasal discharge
Which additional clinical signs can be indicative of a chronic nasal foreign body obstruction?
Chronic clinical signs
Halitosis
Enlarged regional lymph nodes
In addition to the clinical signs seen in acute presentation
What should be done before attempting to remove a nasal foreign body?
Diagnostic imaging to assess the nasal cavity and nasopharynx should be done before attempting to remove a foreign body
What can be done to remove a nasal foreign body?
Rhinoscopy
Nasal flush
May need surgical removal
Which fungus most commonly causes canine fungal rhinosinusitis?
Aspergillus fumigatus
What is the pathophysiology of canine fungal rhinosinusitis?
Aspergillus fumigatus is a commensal fungus which for unknown reasons can form fungal plaques, granulomas and cause bony destruction of the nasal turbinates and is severe cases destruction of the maxilla, orbit and cribriform plate
What is the typical clinical presentation of canine fungal rhinosinusitis?
Chronic, progressive clinical signs
Unilateral to bilateral discharge
Mucopurulent discharge to epistaxis
Sneezing
Head shyness
± Rhinarial depigmentation
± Rhinarial crusting
± Periocular swelling
How do you diagnose canine fungal rhinosinusitis?
Diagnostic imaging
Rhinoscopy
Nasal biopsy
Nasal flush
Sinoscopy
What is the appearance of canine fungal rhinosinusitis on radiography?
Increased radio-lucency
Increased soft tissue opacity indicative of granulomas (however could also be discharge)
Loss of nasal turbinate pattern
Bony destruction
What is the appearance of canine fungal rhinosinusitis on CT?
Loss of nasal tubinates
How can rhinoscopy be used to help diagnose canine fungal rhinosinusitis?
Visualisation of the fungal plaques
Allows for biopsy of the fungal plaques
Allows for biopsy of the nasal turbinates
What further tests should be done on biopsies of the fungal plaques?
Histopathology
Culture
How do you treat canine fungal rhinosinusitis?
Nasal instillation of anti-fungal agents and trephination of the frontal sinuses
What is the prognosis for canine fungal rhinosinusitis?
Generally the prognosis is fair to good however the treatment for this condition is expensive and often requires multiple treatments. Furthermore, relapses can commonly occur
What are the two forms of feline aspergilliosis?
Sino-nasal aspergilliosis
Sino-orbital aspergilliosis
What is the typical clinical presentation of feline aspergilliosis?
Chronic, progressive clinical signs
Unilateral to bilateral nasal discharge
Serous to mucopurulent nasal discharge
Sneezing
± Epistaxis
± Exopthalmus
± Granuloma protruding from the nares
± Stertor
What should you always check in cats that present with cryptococcus?
Check the FIV/FeLV status in cats that present with cryptococcus as cryptococcus in an opportunistic pathogen that presents in immunodeficient patients
What is the most common nasal tumour in dogs?
Adenocarcinoma
What is the most common nasal tumour in cats?
Lymphoma
What is the typical clinical presentation of nasal neoplasia?
Chronic, progressive clinical signs
Unilateral to bilateral nasal discharge
Mucopurulent to epistaxis
Obstruction of airflow at the nostril(s)
Facial pain
Facial deformity (rare)
Lymph node enlargment
Cachexia, poor body condition
What can be used to diagnose nasal neopasia?
Diagnostic imaging (remember to image the rest of the body to assess for metastasis)
Rhinoscopy
Nasal biospy
What is the typical clinical presentation of chronic rhinitis?
Chronic clinical signs
Bilateral nasal discharge
Serous to mucopurulent nasal discharge
Systemically normal
Make sure to rule out any other causes of chronic inflammation
How do you manage idiopathic chronic rhinitis?
Idiopathic chronic rhinitis is unlikely resolve with treatment, so it is important to educate the owners about this but reassure them that their pet is in no immediate danger
What is an oronasal fistula?
An oronasal fistula is an abnormal opening between the oral and nasal cavity
What can cause oronasal fistulas?
Dental disease
Trauma
Oral neoplasia
How do you treat an oronasal fistula?
Surgical repair
