1) diseases of the nasal cavity and larynx Flashcards
Describe the functional anatomy of the nasal cavity
Nostrils, nasal plane, bony case, nasal septum, right and left halves of the nasal cavity, nasal conchae, choanae
- Respiratory and olfactory region
- Regulation of airflow (pulmonary oedema, mouth breathing!)
- Heating and humidification
- Mucosal cleaning
- Olfaction (cribriform plate, brain!)
Describe the history and clinical signs of the nasal cavity
Discharge, sneezing, bleeding, pain, stridor, dyspnoea, reverse sneezing
- Systemic diseases!
• Discharge (distemper, viral rhinotracheitis)
• Epistaxis (bleeding disorder)
- Physical examination
• Shape, nasal stridor, closing the mouth, discharge uni- / bilateral, inspection of the mouth (teeth!), depigmentation
What are some special diagnostic procedures?
Radiography • Sedation, positioning, limited value - Rhinoscopy • Anaesthesia, tracheal intubation, sphinx-like posture, visualization and biopsy! Treatment? - CT, MRI - Olfactory tests
Describe the general overview of diseases of the nasal cavity and frontal sinus
Congenital diseases
• Malformation of the nasal plane
• Oronasal, oropharyngeal clefts
• Primary ciliary dyskinesia / Kartagener’s syndrome
- Rhinitis
• Viral, bacterial, mycotic, specific (neurogenic) - Tumours
• Nasal plane / nasal cavity / frontal sinus - Epistaxis
- Trauma
Viral rhinitis of cats?
FHV-1, FCV 80-90% (URT)
➢ Paroxysmal sneezing, serous ocular and nasal discharge in 5 days mucopurulent
➢ Can be concurrently infected with both and cause similar clinical signs, and contribute towards chronic infection
o FHV can also have severe conjunctivitis and corneal ulceration
o FCV can have mild ocular signs, oral ulcers and gingivitis, lameness (self-limiting)
Chronic carriers: no signs or sneezing, mild nasal discharge, gingival ulceration
➢ Chronic viral disease can also lead to mucosal destruction and secondary bacterial infection leading to a syndrome called “chronic snufflers”
o Unilateral/bilateral mucopurulent nasal discharge
o +/- chronic sneezing
➢ Diagnosis
o PCR on conjunctival swab
o “chronic snufflers”
▪ Rule out other causes of mucopurulent nasal discharge
▪ Radiographs
▪ Scoping
▪ +/- culture of nasal discharge
➢ Treatment? Prevention!
o Supportive therapy: nebulization and humidification, lysine
o Antibiotics: doxycycline to prevent secondary bacterial infections
o “Chronic snufflers”
▪ 8 weeks of doxycycline or clindamycin (good bone penetration)
▪ +/- short courses of relapse
▪ +/- saline nebulization
▪ Anti-viral medication
Viral rhinitis of dogs?
Canine distemper - profuse mucopurulent discharge
- PCR !
Canine Herpes Virus - profuse mucupurulent discharge
diagnosis by autopsy
Bacterial rhinitis aetiology
usually secondary to:
viral infections
foregin body
tumour, disruption of mucosal integrity
Causes of conjunctivitis in cats
Mycoplasma and Chlamydophila felis
Causes of primary respiratory tract infections
Mycoplasma, Bordetella bronchiseptica, Clamydophila felis (cats)
Diagnosis of bacterial rhinitis
Culture of nasal swab
conjunctivits swab and PCR
Treatment of BActerial rhinitis
Treatment of underlying disease
supportive therapy with nebulizaiton and humidification, nutritional support
AB: DOxycycline for up to 3 weeks
Antibiotics in bacterial rhinitits?
Doxycycline for up to 3 weeks
Mycotic rhinitis in Dogs aetiology
Aspergillus spp. > cryptococcus
typically canine disease, especially young dogs with long nose
purulent to sanguineous discharge, pain on palpation, ulceration of nasal planum and signs of systemic illness
can have neurological signs
Mycotic rhinitis in cats aetiology
Cryptococcus - typically feline disease - cryptococcus neoformans
can have neurological signs with cryptococcus var gatti
LCAAT is used for monitoring titre levels as an indication of response therapy
Diagnosis of mycotic rhinitis
Rhinoscopy: Scoping (fungal plaques), bone resorption, atrophy of the conchae
• Serology – fungal antibody titres
• Biopsy, cytological demonstration of organisms
• culture
