55 - Respiratory System: Upper Respiratory Tract Conditions

What are the 5 parts of the upper respiratory tract?

Nasal cavity/Paranasal sinuses

Pharynx

Guttural pouch

Larynx

Trachea

What is congestion?

Dilation of the mucosal vessels

What is epistaxis?

Blood flow from the nose

Unilateral/Bilateral epistaxis is more commonly from the URT

Unilateral

Unilateral/Bilateral epistaxis is more commonly from the lungs

Bilateral

What color is blood in the respiratory system?

Red

What are causes of hemorrhage in the respiratory system?

Local trauma

Submucosal erosions from inflammation

Neoplasia

What is exercise induced pulmonary hemorrhage?

Pulmonary hemorrhage that occurs after exercise

Exercise induced pulmonary hemorrhage is seen in which species?

Race horses

What gross lesions is seen with exercise induced pulmonary hemorrhage?

Large areas of dark brown discoloration in caudal lung lobes

T/F - The guttural pouch drains well because it's part of the middle ear

False - does not drain well

The guttural pouch has a close anatomic relationship to what 2 things?

Carotid arteries

Cranial nerves (VII, IX, X, XI, XII)

What pathogens typically affect the guttural pouch?

Fungi

Bacteria

What causes guttural pouch mycosis most commonly?

Aspergillus species (in inhaled hay)

What gross lesions are seen with guttural pouch mycosis?

Focal, rounded, railed plaques in dorsal/lateral walls of ONE (unilateral) guttural pouch

Why can recurrent/fatal hemorrhage occur with guttural pouch mycosis?

Plaques erode through carotid artery

What histological lesions are seen with guttural pouch mycosis?

Necrotic inflammation of the mucosa with vasculitis & intralesional fungal hyphae

What is empyema?

Accumulation of neutrophils with a space

Empyema is a sequela to what?

Suppurative inflammation of nasal cavities

Although presentation for guttural pouch empyema & guttural pouch mycosis are very similar, what secondary lesion tells them apart?

No erosion of internal carotid artery with guttural pouch empyema

What causes infectious rhinitis?

Secondary to changes in nasal cavity microbiotia

What happens iwth chronic rhinitis?

Destruction of nasal conchae

Septum deviation

What is caused if inflammation caused by infectious rhinitis travels to the sinuses?

Sinusitis

What is caused if inflammation caused by infectious rhinitis travels to the facial bones?

Osteomyelitis

What is caused if inflammation caused by infectious rhinitis travels through the cribriform plate?

Meningitis

What is caused if inflammation caused by infectious rhinitis travels into Eustachian tubes?

Otis media

Guttural pouch empyema

What is caused if inflammation caused by infectious rhinitis travels into inner ear?

otis interna

Vestibular syndrome

What is the mildest form of rhinitis?

Serous

What gross lesions are seen with serous rhinitis?

Mucosal hyperema

Clear fluid production (from serous glands)

What causes serous rhinitis?

Mild irritants

Cold air

Early viral infections

URI

Mild allergic reactions

What gross lesions are seen with catarrhal rhinitis?

Serous & mucoid discharge

What does Mucous exudate look like?

Thick, translucent-slightly turbid, viscous fluid

What is seen on histology with catarrhal rhinitis?

Mucous gland hyperplasia

Catarrhal rhinitis is more acute/chronic

Chronic

Suppurative rhinitis is more acute/chronic

Acute

What is seen with Suppurative rhinitis?

Neutrophilic exudate

+/- mucosal necrosis

+/- Secondary bacterial infections

What gross lesions are seen with Suppurative rhinitis?

Thick & opaque, white-green-brown exudate that may obstruct nasal passages

What is fibrinous rhinitis?

Inflammation that causes increased vascular permeability = abundant plasma fibrinogen = fibrin

What gross lesions are seen with fibrinous rhinitis

Yellow-tan-grey friable mat on nasal mucosa

What is pseudodiphtheritic rhinitis?

Intact underlying mucosa under a fibrinous exudate that can be removed

What is diphtheritic or pseudomembrane rhinitis?

Ulcerated mucosa under a fibrinous mat that is difficult to remove

What gross lesions are seen with granulomatous rhinitis?

Multifocal-coalescing tan granulomas

+/- polypoid nodules (chronic)

What histo lesions are seen with granulomatous rhinitis?

Epithelioid macrophages with a few lymphocytes & plasma cells

What causes granulomatous rhinitis?

Chronic allergic infalmmation

Ingectious etiologies

What is the number one cause of tracheitis?

Viral infections

T/F - Viral infections are normally mild & transient

True

When do viral infections become more complicated?

When secondary baterial infections occur

What is a noninfectious cause of Tracheitis?

Aspiration

Sinusitis is frequently combined with _________ and is termed ___________

rhinitis; rhinosinusitis

What are causes of sinusitis?

Wounds (septic or penetrating)

Improper dehorning

Maxillary tooth infection (horses and dogs)

What happens if sinusitis extends to adjacent bone?

Osteomyelitisis

What happens if sinusitis extends through ethmoidal conchae into meninges & brain?

Meningitis

What clinical signs are seen with canine infectious respiratory disease complex (CIRD)?

Acute onset of coughing

+/- Rhinitis/Pharyngitis

What are 4 pathogens that make up the CIRD?

CAdV-2

PIV

Bordetella bronchiseptica

Streptococcus zooepidemicus

What gross lesions are seen with CIRD?

Catarrhal-mucopurulent material

+/- Pneumonia

LN & tonsil enlargment

Which 2 pathogens cause mycotic & algae rhinitis/sinusitis in dogs most commonly?

Aspergillus

Penicillium

Which breed may be predisposed to Aspergillus rhinitis/sinusitis?

German Shepherds

What gross lesions are seen with mycotic & algae rhinitis/sinusitis?

Necrosis of nasal epithelium

Plaques of fibrinopurulent exudate

What is seen on histology with mycotic & algae rhinitis/sinusitis?

Granulomatous inflammation admixed with fungal hyphae

What causes feline viral rhinotracheitis?

Feline herpesvirus 1

Feline herpesvirus 1 may have a coinfection with what 2 things?

Secondary bacteria

Feline calicivirus

What happens to feline herpes virus in the body?

Becomes latent in various ganglia

What gross lesions are seen with feline viral rhinotracheitis?

Necrosis & infalmmation of conjunctival, nasal passages, pharynx, trachea

What gross lesions are seen with chronic feline viral rhinotracheitis?

Rhinitis & Sinusitis with persistent suppurative discharge

What gross lesions are seen with feline calicivirus?

Severe rhinitis

Ulcerative gingivitis, glossitis & stomatitis

Bronchiolitis & interstitial pneumonia

FeHV-1 & Feline Calcivirus account for ~____% of all feline respiratory disease

80%

Which 2 fungi cause cryptococcosis in felids?

Cryptococcus neoformans

Cryptococus gattii

What gross lesions are seen with cryptococcosis in felids?

Discrete nasal granulomas

Mucosuppurative exudate filling entire nasal cavity & paranasal sinuses

What is seen on histology with cryptococcosis in felids?

Yeast with abundant clear capsule

What pathogens are cause porcine progressive atrophic rhinitis?

Pasteurella multocida

Bordetella bronchiseptica

Glasserella parasuis

Porcine cytomegalovirus

Which 2 pathogens are cause porcine progressive atrophic rhinitis most commonly?

Pasteurella multocida

Bordetella bronchiseptica

What gross lesions are seen with porcine progressive atrophic rhinitis?

Deviated septum

Atrophic, Asymmetric conchae

Inflammation & atrophy of nasal conchae

Necrotic rhinitis is seen in young/old pigs

Young

What causes Necrotic rhinitis (event not pathogen)

Extension of penetrating wound = clipping of needle teeth most common

What pathogen causes Necrotic rhinitis?

Fusobacterium necrophorum

What gross lesions are seen with Necrotic rhinitis?

Necrosis & suppuration of the nasal cavity and turbinates

What clinical signs are seen of Necrotic rhinitis?

Face & snout swollen & deformed

Persistent nasal discharge

Oestrus ovis is a _______ __________ seen primarily in sheep

Nasal myiasis

What pathogen causes necrotic laryngitis?

Fusobacterium necrophorum

Necrotic laryngitis is a common disease of ________ _______

feedlot cattle

How does necrotic laryngitis occur?

Secondary to viral infection

Traumatic injury

What gross lesions are seen with necrotic laryngitis?

Well-demarcated, dry yellow-grey, fibrinonecrotic exudate

Inflammation of mouth or larynx

What are 2 ways fatality occurs with necrotic laryngitis?

Severe toxicity

Laryngeal obstruction = aspired exudate = bronchopneumonia

What causes infectious bovine rhinotracheitis?

Bovine herpes 1

What gross lesions are seen with infectious bovine rhinotracheitis?

Formation of a thick layer of fibrinonecrotic material in sinuses & trachea

Hyperemia & necrosis of nasal, pharyngeal, laryngeal & tracheal mucosa

What is the difference between infectious bovine rhinotracheitis and Necrotic laryngitis?

Location!