1.1.1: Canine and feline nasal disease Flashcards
Signs of nasal disease
- Sneezing
- Snorting
- Nasal discharge
- Epistaxis
- Nasal pain (common with neoplasia)
- Nasal ulceration / loss of pigment around the nostrils
- Reverse sneezing is not usually a sign of severe disease
If nasal discharge (e.g. mucoid, bloody) starts unilateral and then becomes bilateral, what does this tell you about the disease process?
- If it starts unilateral and then goes bilateral, the disease is getting worse
- Crossing the midline means destruction is occurring
What history questions could you ask when investigating nasal disease?
- When was the animal last seen normal? (Classify disease as acute vs chronic)
- Is it one or both nares affected?
- Nature of discharge? Presence of blood?
- Any pain?
- Any difficulty eating?
- Any halitosis?
What aspects of the clinical exam will you pay particular attention to in the animal with nasal disease?
- Symmetry
- Eyes
- Pain (palpate over the dorsum of the nose and sinuses)
- Air flow
- Teeth
- Nasal planum depigmentation
- Lymph nodes
Differential diagnoses for chronic nasal disease
- Foreign body
- Neoplasia (±epistaxis, esp if unilateral)
- Aspergillosis (±epistaxis)
- Rhinitis e.g. allergic rhinitis is a diagnosis of exclusion. Primary bacterial rhinitis is rare!
- Dental disease
- Chronic post-viral disease in cats (e.g. kittens infected with herpes developing chronic issues)
Common in bold.
What should you consider if there is epistaxis and blood in any other body system?
Clotting disorders are always a possibility. Epistaxis could be an early sign.
Describe the cause and pathogenesis of chronic rhinitis in cats
- Feline herpesvirus 1 is suspected to play a role in chronic nasal inflammation resulting in destructive rhinitis (turbinates can be destroyed)
- There is inflammation and swelling of the conchae -> increased mucus production and secondary infection
- Mucopurulent secretion may contain blood -> sometimes disease is severe enough to result in loss of conchae
Diagnosis of chronic rhinitis in cats
- Noticeable on rhinoscopy as loss of conchae / turbinates means there is lots of room to move the rhinoscope
- Appearance of chronic post-viral rhinitis in cats appears similar endoscopically to aspergillosis of nasal passages in dogs
- May have history of respiratory disease / viral infection as a kitten
3 most common causes of chronic nasal disease in cats
- Tumours
- Foreign bodies e.g. grass blades
- Rhinitis
Polyps are also a possibility. Other causes are miscellaneous or undiagnosed.
Which fungi most commonly causes fungal rhinitis in dogs?
A. fumigatus (causes aspergillosis)
Which species is fungal rhinitis more common in?
- Mainly seen in dogs, especially in medium to long-nosed breeds
- Rare in cats
Describe the pathogenesis of aspergillosis / fungal rhinitis
- A. fumigatus often causes fungal rhinitis
- Disease is generally restricted to the nasal cavity and sinuses but is markedly destructive to the turbinates
- It can erode the frontal bones and cribiform plate, even getting into the brain
Clinical signs of fungal rhinitis / aspergillosis
- Nasal discharge: may be mucopurulent with intermittent epistaxis
- Discharge may progress from unilateral to bilateral.
- Discharge often smells dank (like a cellar)
- Ulceration / depigmentation of the nasal planum
- Pain on palpation
- Sneezing
- Facial deformity
- Neuro signs
Diagnosis of fungal rhinitis / aspergillosis
- History and clinical signs
- Imaging: radiography of nose and sinuses / CT or MRI if available
- Rhinoscopy: rigid or flexible endoscope. Flexible allows anterograde sinuscopy. Can take guided biopsy.
- Cytology
- Serology
- Best method: visualise the plaque or culture the fungus from a sample
What are the disadvantages of using serology to diagnose aspergillosis?
- Sensitivity and specificity not great
- Can produce false negatives commonly
- Can produce false positives if the animal has previously had and cleared the infection