Upper Airway Diseases in Small Animals

Question 1

Diseases of Sinus / Nose
* Most common diagnoses

Answer 1

• Inflammatory rhinitis > Lymphocytic-plasmacytic rhinitis
• Neoplasia
• Infections > Fungal, viral, (bacterial)
• Other (foreign body,…)

Question 2

which common causes of nasal discharge are usually bilateral

Answer 2

• inflammatory rhinitis
• if epistaxis: coagulopathy, hypertension

Question 3

upper airway issues important PE considerations

Answer 3

• Palpate over sinonasal region–symmetry
• Retropulsion of eyes
• Ulceration or facial deformity
• Oral examination
• Mandibular lymph nodes

Question 4

Characterize Nasal Discharge - how to

Answer 4

• Unilateral vs bilateral
• Clear, mucoid, bloody (epistaxis)
• Check patency of nostrils (if not patent maybe a mass?)

Question 5

oral issues that can impact the nasal cavity

Answer 5

• tooth root abscess, fistula…

Question 6

patient with nasal discharge - what one thing we should do, at the very least?

Answer 6

FLUSH THE NOSE!
* Can dislodge a foreign body
* Will improve visualisation when rhinoscopy

Question 7

skull radiographs pros and cons for nasal issues

Answer 7

Pros:
* Available in all clinics
* For good position heavy sedation required
* Indicated if asymetry of the face and suspicion of neoplasia
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Cons:
* Cannot distinguish between fungal infection and tumor
* Almost same price as CT-scan and less sensitive

Question 8

Sinonasal Aspergillosis Diagnosis

Answer 8

Radiographs
* Increased soft tissue opacity in nasal cavity > Liquid or mass or turbinates destruction??
* Usually no destruction of nasal bones > Versus advanced neoplasia which maybe destructive

Question 9

Advanced imaging CT-Scan use for nasal issues?
- what is it good for if treating fungal disease?

Answer 9

• Can distinguish between:
  > Destruction of turbinates (Aspergillosis)
  > Mass effect (Tumor)
• +/-destruction of bone or cribiform plate
• Tooth root evaluation
• Foreign body localization
• But…..$$$$
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  > if we have fungal disease, we will treat locally > we do NOT want this liquid to go to the brain, or it can kill the dog
  > NEED INTACT CRIBRIFORM PLATE

Question 10

When should we do Rhinoscopy?

Answer 10

• For foreign body removal
• To confirm fungal plaques

Question 11

Sinonasal Aspergillosis
- pathogen, where found?
- transmission? lesion localization?
- who gets it?

Answer 11

• Aspergillus spp. widespread in environment
• Can be found in normal dogs
  > Invasion & infection of small % of dogs
  > Trauma, individual susceptibility
• Frontal sinuses, nasal passages
• Infection most common in young male dogs

Question 12

Sinonasal Aspergillosis
* Clinical signs

Answer 12

• Nasal discharge
  > Mucoid to mucopurulent
• Sneezing, epistaxis
• Depigmentation & ulceration of nasal planum common
• Facial pain

Question 13

Sinonasal Aspergillosis Diagnosis

Answer 13

• 2 or more positive results from:
• Imaging (CT, MRI, rhinoscopy)
• Biopsy
• Aspergillus titer
• Aspergillus culture (from a tissue biopsy)
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• Usually diagnosis based on CT-scan and presence of “plaques” on rhinoscopy

Question 14

Aspergillosis Nasal Biopsies
- how to take
- what we look for on histo?
- culture?

Answer 14

• Can take biopsies “blindly” under GA
• Multiple biopsies (patchy distribution)
• Rarely done
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• Histology: inflammation, fungal organisms
• Send culture as well to check for bacterial infection (fungal culture usually not sent because of long turn around time)

Question 15

Sinonasal Aspergillosis Treatment, efficacy

Answer 15

• **Debridement of plaques
• Topical antifungal therapy**
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• Infusion of clotrimazole under general anaesthesia
• dog on its back, goal is to fill nose with liquid
  > so we block exits, the inject liquid, and let it sit in there for an hour
• 65% success after 1 treatment
• 87% success after >1 treatments

Question 16

Sinonasal Aspergillosis Alternative Treatment, success rates? issues?

Answer 16

Systemic therapy
* Itraconazole has ~60-70% success rate
* Ketoconazole has 40-60% success rate
* Costly & prolonged
* Side effects include hepatotoxicity

Question 17

Sinoasal Aspergillosis Prognosis

Answer 17

• Response to treatment favourable
  > Can be expensive
• Recurrence possible
• Chronic or episodic nasal discharge (~15-20%)
  > Turbinate destruction, chronic lymphocytic- plasmacytic rhinitis, secondary bacterial infections

Question 18

Nasal Mycoses in Cats
- what is common? transmission?

Answer 18

• Very unusual for cats to be affected by Aspergillosis, but another fungal infection is common…
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• Cryptococcus spp.
• Affects cats (less common in dogs)
• Airborne transmission (bird guano-Pigeons++)

Question 19

Cryptococcosis: Clinical Features, signs

Answer 19

• Mucopurulent nasal discharge, sneezing, Up to 80% cats
• Proliferative soft tissue masses, ulcerative lesions ~70% of cats
• Lesions can be deforming

Question 20

Cryptococcosis: Diagnosis

Answer 20

• Clinical signs & organism identification (or serology)
• Cytology or histopathology diagnostic in 75% of cases
  > Cats with only CNS disease may need CSF tap

Question 21

cryptococcus cytology appearance

Answer 21

large capsule around organism

Question 22

Treatment and Prognosis of Cryptococcosis

Answer 22

• Amphotericine +/-flucytosine in cats with CNS infection
• Or fluconazole (cured in 4months-average)
• Or Itraconazole but longer treatment required (9 months average)
• Treatment continued until titers are negative (titers checked monthly)
• Recheck 3 and 6 months after treatment finished to check for relapse
• 75% of cats and 50% dogs respond to treatment
• 15 to 20% of relapse rate in cats
• Prognosis is good if extraneural disease
• facial deformation will go away for the most part

Question 23

Cryptococcosis: Prognosis

Answer 23

• Good for cats with non-CNS disease
• Guarded for cats with CNS disease, and dogs with any type of infection
• Response rate for cats overall is 75% * Relapse rate is15-20%