Diseases of the nasal cavity Flashcards Preview

SAM 1 > Diseases of the nasal cavity > Flashcards

Flashcards in Diseases of the nasal cavity Deck (49)
Loading flashcards...

What are the clinical signs associated with nasal disease?

  • Nasal discharge
  • Sneezing
  • Pawing at face/pain
  • Resiratory difficulty on inspiration
  • Stertor--noisy respiration (blockage)


Nasal discharge: what should we consider


History and PE findings?

  • Signalment
    • Age--young vs. old
    • Breed--dolichocephalic and brachycephalic
  • History and physical exam findings
    • Character of discharge--unilateral vs. bilateral, serous, mucoid, purulent, hemorrhagic
    • Facial symmetry/asymmetry (soft vs. firm)
    • Dental disease--always check
    • Depigmentation of nasal area (ex: aspergillosis)
    • Local lymph nodes
    • Oropharyngeal examination and otic examination--when polyp is suspected
    • Ocular examination--ocular retropulsion 


Nasal discharge: what should we consider

Advanced clinical tests?

  • Bloodwork (make sure animal can clot)
  • Imaging
    • Rads (not usually helpful)
    • CT/MRI
  • Endoscopy--rhinoscopy
  • Cytology/biopsy/culture and sensitivity
  • Serology titres and PCR--infectious diseases


Nasal discharge--differential list?

  • Neoplasia--important in dogs
  • Rhinitis--important in cats
    • Infectious
      • Fungal, viral (feline upper respiratory disease complex), bacterial, parasitic
    • Inflammatory
      • Lymphocytic/plasmacytic
  • Nasal foreign body
  • Dental disease/oronasal fistulas
  • Trauma
  • Congenital
    • Ciliary dyskinesia
    • Nasopharyngeal stenosis
  • Systemic disorder
    • Coagulopathy
    • Pneumonia (occasionally) 


Nasal foreign bodies


  • Sudden onset
  • Acute sneezing
  • Gagging/reverse sneezing
  • Pawing at nose
  • Discharge--serous to mucoid purulent (won't show immediately)


Nasal foreign bodies


  • Rads--only good for radiodense material
  • CT/MRI
  • Rhinoscopy (endoscope vs. otoscope)
    • Remember to examine caudal nasopharynx
  • Nasal flush
  • Alligator forceps/biopsy
  • Cytology of discharge (rule out other dz)
  • Culture/sensitivity (usually unnecessary)
  • Explorative sx (unlikely)


Infectious rhinitis--feline upper respiratory disease complex

Potential infectious agents?

  • 90% of cases
    • Feline herpes virus
    • Feline calicivirus
  • 10% of cases
    • Chlamydophila felis
    • Mycoplasma spp
    • Coronavirus
    • Bordetella spp


Infectious rhinitis--feline upper resp. disease complex

Clinical signs

  • Similar for all agents
  • Differences include:
    • Herpes virus
      • Ulcerative keratitis
      • Punctate or dendritic ulcers
    • Calicivirus
      • Ulcers on nose, tongue, hart palate
      • Pneumonia
      • Lameness
    • Chlamydophila felis
      • Conjunctivitis w/ chemosis
    • Carrier states w/ all
      • Herpes virus shed during stress
      • Calicivirus and chlamydophila can be shed w/ or w/o stress


Feline herpes virus--rhinotracheitis






  • Spread--direct contact, fomites
  • Shed in ocular, nasal, pharyngeal secretions
  • Nasal disease--serous then mucopurulent due to secondary bac. infection
  • Establishes lifelong latency--esp. trigeminal nerve ganglia
  • Diagnosis--clinical signs, viral isolation, PCR


Feline herpes virus--rhinotracheitis


  1. Chronic rhinitis/sinusitis--feline chronic rhinosinusitis
    1. Short nosed breeds
    2. Turbinate damage predisposes to secondary bac. infections of the nasal cavity--chronic snuffler
  2. Chronic conjunctivitis
  3. Fibrosis of lacrimal ducts--epiphora

80% of recovered cats become carriers and shed when stressed


Feline herpes virus--rhinotracheitis

Transmission cycle?


Feline herpes virus


  • Topical antivirals for ocular disease
    • Idoxuridine, trifluridine, cidofovir
  • Oral antivirals
    • Famciclovir, acyclovir
  • Supportive care
    • Antibiotics for secondary bac. infection
    • Fluid therapy if required
    • Humidify environment
    • Nasal decongestant
    • L-lysine?
      • Not effective, but >80% of vets use it--DON'T USE


Feline herpes virus


  • Does not prevent infection
  • Does reduce severity
  • Parental or intra-nasal
    • Parental--blocked by maternal antibodies, does not prevent a carrier state
    • Intranasal--useful in outbreaks, not blocked by maternal antibodies
      • Post-vaccine sneezing common
      • May prevent a carrier state
      • Shed


Feline calicivirus (FCV)



Mutation rates?



Incubation period?

  • Longer survival in the environment
  • Can be resistant to routine disinfectants
  • High mutation rate--new strains always being produced w/ no cross-protection from vaccines or other strains (RNA virus)
  • Many isolates--various antigenic and pathogenic types
  • Direct transmission or via fomites
  • Incubation period short: 2-4 days


Feline calicivirus

Transmission cycle?


Feline calicivirus

Clinical signs?

Difference from feline herpes virus?


  • Clinical signs
    • Typical signs for feline viral rhinotracheitis
    • Oral and nare ulcers are common
  • FCV vs. FHV
    • Pneumonia more common w/ FCV
    • FCV can result in GI signs
    • FCV can cause lameness
  • 50% of infected cats will shed the virus at 75 days post-infection; don't need stress to shed the virus



Feline calicivirus

2 other syndromes associated w/ FCV?

  1. Limping kitten syndrome
    • Lameness, ulcers on paws, sore joints, polyarthritis
  2. Virulent hemorrhagic systemic syndrome
    • Outbreak in 2000, group of housed cats
    • Affected even well-vaccinated cats, the traditional vaccine did not protect the cats from this variant
    • Upper resp signs preceded systemic signs
    • Edema, hepatitis, diarrhea, pustular dermatitis, hemorrhagic cystitis found
    • 40-60% mortality w/ this strain


Feline calicivirus



  • Treatment
    • Largely supportive
      • Antibiotics
      • Nursing care/rehydration
    • Interferon may be effective
  • Sequelae
    • Chronic rhinitis/sinusitis/conjunctivitis
    • Carrier state


Chlamydophila felis

Bac. type

Clinical signs


  • Intracellular bacteria
  • Clinical signs are similar to FHV and FCV
    • Conjunctivitis and chemosis are hallmark signs
  • Diagnosis
    • PCR--swab from conjunctiva, nares, or oropharynx
    • Cytology--conjuntival swab--intracytoplasma inclusion


Chlamydophila felis



  • Treatment
    • Topical tetracyclines or erythromycin
    • Systemic signs require oral doxycycline and azithromycin
  • Prevention
    • Vaccination (not a core vaccine)
    • Vaccination is more reactive than other antigens


Overview of treatment for cat flu (11 steps)

  1. Outpatient treatment if possible--or isolation
  2. Keep warm and hydrated
  3. Remove crusts from nose and eyes, use saline nasal drops
  4. Humidify air--steam vs. nebulization 
  5. Topical decongestants for 1-2 days
    • Pseudoephedrine, phenylephrine (preferred), oxymetazoline
  6. Systemic antibiotics for secondary bac. infection
    • Enrofloxacin, azithrymycin, amoxicillin, clavulanic acid, doxycycline, marbofloxacin?
  7. Topical opthalmic solutions--antiviral? Antibac? Or both
  8. Interferon
  9. Oral antiviral?
  10. Lysine? Does it work in FHV?
  11. Anti-inflammatories--steroid vs. non-steroidal (piroxicam) for a few days


Bacterial rhinitis

Primary disease process?


Antibiotics response?

Usually what?

  • VERY RARELY primary disease process
  • Mucopurulent to purulent nasal discharge
  • Transient response to antibiotics
  • Usually secondary to an underlying disease process
    • Foreign body?
    • Tooth root abscess?
    • Chronic viral infection?
    • Fungal infection?
    • Neoplasia?


Fungal rhinitis


  • Dogs--predominantly Aspergillus fumigatus
    • Worldwide distribution
    • Dessiminated disease in dogs often involved A. terreus, A. deflectus, or A. niger
  • Cats and dogs--Cryptococcus neoformans var. neoformans
    • Often found in avian droppings/fowl manure (esp. pigeons)
    • C. neoformans var. gatii found in specific eucalyptus trees


Nasal aspergillosis--dog

Clinical signs?

  • Sneezing, uni/bi nasal discharge
  • Nasal ulceration and depigmentation
  • +/- facial distortion
  • Nasal airflow usually ok; turbinate destruction (compare to neoplasia)
  • Most cases systemically ok


Nasal aspergillosis--dog

Cribiform plate invasion--tests

  • Imaging--do before rhinoscopy or nasal flush
  • Rads--can't distinguish between fungal rhinitis or neoplasia
  • CT or MRI--more helpful than rads
  • Rhinoscopy--white plaques
  • Tissue biopsy/cytology--hyphae
  • C/S--best done from plaque, not discharge


Nasal aspergillosis--dog


  • Debridement
    • Break off plaques, soak in nose to treat nasal passage
    • Can drill hole in frontal sinus to aid in location of plaques
    • Be careful not to damage cribiform plate
  • Infuse 1% clotrimazole or 2% eniloconazole into nasal cavity for 1hr
    • Rotate nose around--turn 90o every 15 min
    • Risks: aspiration pneumonia (severe irritant), neuro signs (damaged cribiform plate--contraindication)
    • Reeat procedure every 4wks, repeat rhinoscopy, remove any plaques and repeat soak if required
  • Systemic antifungal medication
    • Can use in cases of osteolysis arounf cribiform plate
    • Get a fungal sensitivity
    • Itraconazole, posaconazole, voriconazole (last 2 $$$)


Nasal aspergillosis--dog

When is it better to NOT do nasal flushes?

When there is osteolysis


Fungal rhinitis--overview

Dogs: Aspergillosis

  • Dolichocephalics, young adults
  • Unilateral nasal discharge may become bilateral
  • 20% chance of seeing hyphae on cytology of d/c
  • White plaque on rhinoscopy
  • Antibody titer not reliable
  • C/S: from plaque, not discharge
  • Rule out neoplasia: biopsy
  • Clotrimazole locally


Fungal rhinitis--overview

Cats and sometimes dogs: cryptococcosis

  • Localized or systemic
  • Unilateral or bilateral d/c
  • +/- facial asymmetry
  • Submandibular lymph node enlargement
  • Chorioretinitis
  • Organism often in nasal d/c
  • C/S
  • Serum titer very reliable (antigen test, not antibody)
  • Conazoles systemically