Term
| What are the possible consqeuences of dz affecting the airways? |
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Definition
-coughing and sneezing - result of irritation and to move and expel mucus
-airway obstructions - by mucus, exudate, thickening of mucosal walls and bronchoconstriction
-wil reduce ventilation of the lungs
-impaired defences - damage to mucociliary escalator |
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Term
| List development abnormalities associated with airways |
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Definition
-Brachiocephalic airway syndrome
-Cleft palate
-Cysts
-Guttoral pouch tympany
-Hypoplastic epiglottis
-Tracheal collapse |
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Term
| Brachiocephalic airway syndrome |
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Definition
| Range of anatomical abnormalities found in brachiocephalic breeds that result in obstruction of the upper air passages |
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Term
| Describe the combination of anatomical problems and secondary changes associated with brachiocephalic airway syndrome |
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Definition
Anatomical problems
-stenotic nares
-elongated and often thickened soft palate
-thickened tounge
-turbinates may protrude into nasopharynx
-hypoplastic trachea in some cases
Secondary changes
-collapse and obsruction of nares
-everted laryngeal saccules
-everted tonsils
-inflam and oedema e.g. palate, larynx
-laryngeal collapse |
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Term
| What clinical signs may result from upper airway obstruction? |
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Definition
-Resp. noises
-Gagging, retching, vomiting
-Dysponea, exercise intolerance, cyanosis, collapse |
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Term
|
Definition
| Failure of closure of the palatine shelves causes a defect in the palate |
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Term
| What are the possible consequences of cleft palate? |
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Definition
-Food can directly access the nasal cavity from the oral cavity
-Aspiration pneumonia is a common sequel |
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Term
| Name different types of cysts that may obstruct the airways and the species associated. |
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Definition
-Epidermal inclusion cysts (horses)
-Paranasal sinus cysts (horses)
-Cystic nasal conchae (cattle)
-Subepiglottal and pharyngeal cysts (horses) |
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Term
|
Definition
| Defect of the nasalpharyngeal opening that results in trapping of air and mucus in the guttoral pouch |
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Term
| What are the potential consequences of guttoral pouch tympany? |
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Definition
-Pressure on the oesphagus and trachea can cause dysphagia and dysponea.
-Can lead to aspiration of food and resultant pneumonia
-Can predispose to guttoral pouch bacterial infection. |
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Term
|
Definition
-Under-development of the epiglottis
-Small epiglottis may become entrapped under arytenoepiglottic fold causing airway obstruction and resp. noise |
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Term
| Tracheal (tracheobronchial) collapse |
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Definition
-Dorsoventral flattening of the trachea
-Results from deformity in supporting cartilage and causes a widening of the dorsal tracheal membrane |
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Term
| What are the potential consequences of tracheal collapse? |
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Definition
-The widened dorsal tracheal membrane may prolapse into the trachea during inspiration
-Membrane may become thickened if it becomes chronically inflamed
-Varying degress of resp. noise incl. "goose-honk" cough |
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Term
| List potential circulatory disturbances associated with airways |
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Definition
-Congestion and hyperaemia
-haemorrhage
-oedema
-Progressive ethmoid haematoma in horses |
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Term
| Define congestion and hyperaemia |
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Definition
Congestion - PASSIVE - reduced outflow of blood
(can be a non-specific finding at PM)
Hyperaemia - ACTIVE - increased blood flow into tissues and vasodilation |
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Term
| Some causes of airway haemmorhage |
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Definition
-trauma
-inflam
-infection
-septicaemia / sepsis
- clotting defects
-neoplasia
-progressive ethmoid haematoma (horse) |
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Term
| Progressive ethmoid haematoma (horse) |
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Definition
Haemorrhagic polypoid masses that arise in the ethmoid region
-with areas of haemorrhage and organisation and the formation of fibrous granulation tissue, macrophages and haemosiderin deposition |
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Term
| What are the potential consequences of airway oedema? |
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Definition
| Obstruction of airflow - can be a medical emergency |
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Term
| What is oedema of the airways commonly associated with? |
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Definition
-Local inflammation/trauma (most commonly)
-Systemic dz (occasionaly) |
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Term
| List degernerative diseases associated with the airways |
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Definition
Laryngeal paralysis
Includes - Equine laryngeal hemiplegia (roaring) |
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Term
|
Definition
| paralysis and atrophy of the dorsal and lateral cricoarytenoid muscle - results in failure of one or both the arytenoid cartilages to abduct during insipiration |
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Term
| What is the cause of laryngeal paralysis? |
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Definition
| Impairment of the recurrent laryngeal nerve |
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Term
| What are the consequences of laryngeal paralysis? |
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Definition
| Obstruction of the airways and so hypoxia |
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Term
AFTER 23
What type of dog is predisposed to laryngeal paralysis? uni or bilateral? |
|
Definition
Large breeds predisposed and in dogs it tends to be bilateral
(c.f. horse - usually unilateral and usually L) |
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Term
| Equine recurrent laryngeal neuropathy / laryngeal hemiplegia / roaring |
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Definition
Degeneration of left recurrent laryngeal nerve
-results in paralysis and atrophy of dorsal and lateral cricoarytenoid and so incomlete dilation of the larynx
-flaccid arytenoid cart. is sucked into airway during insp. causing airflow obstuction and turbulence
-turbulence and vibration of loose vocal cords results in roaring sound |
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Term
After 24
What is the cause of recurrent laryngeal nerve impairment in laryngeal paralysis? |
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Definition
NB: long nerve so easily damaged
-congenital abnormality
-primary idiopathic neuronal degeneration
-secondary trauma, compression or irritation of the nerve
e.g. cervical trauma, inj. of irritating substances to neck and so inflam resp., guttoral pouch dz., enlarged LNs, neoplasia
-generalised neuromusc. dz.
-neurotoxins e.g. lead poisoning, hepatic encephalopathy
-secondary to hypothyroidism in dogs
-occasionally arises following anaesthesia |
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Term
BEFORE 25
What type of neoplasms are most common in the upper airways of dogs and cats and horses? |
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Definition
Malignant tumours more common and epithelial origin.
Dog and cat - nasal origin more common
Horse - paranasal origin more common |
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Term
| Name possible upper airway neoplasias |
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Definition
-Epithelial tumours are most common i.e. Carcinoma, adenocarcinoma (malignant non-gland epithelial/glandular origin)
-Lymphoma in cats
-Chondrosarcoma is most common mesenchymal tumour in dogs (malignant) |
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Term
| Examples of upper-airway neoplasias |
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Definition
-Nasal adenocarcinoma
-Squamous cell carcinoma
-Transitional carcinoma
-Lymphoma
-Chondrosarcoma |
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Term
AFTER 26
Briefly describe tumours of the larynx trachea and bronchi / bronchioles |
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Definition
Larynx / trachea tumours are fairly rare, may occur from spread from local tissues.
Tumours of bronchi/bronchioles are rel. uncommon, mostly of epithelial origin, and mostly malignant. |
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Term
| List possible causes of inflam of the airways |
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Definition
-Microbial infections agents e.g. viruses, bact., fungi
-Parasites
-Physical injury (trauma, thermal or chemical), forign body, inhaled irritants
-Toxins (inhaled or haemattogenous
-Allergens
-Extension from local tissue e.g. dental |
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Term
|
Definition
-Serous
-Catarrhal and mucopurulent
-Purulent (suppurative)
-Fibrinous |
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Term
| Describe what happens following injury to the airway epithelium |
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Definition
-detachment and shedding of ciliated cells
-basement membrane denuded
-increased secretions from seromucous glands
-vasodynamic changes - heat, swelling, redness, hyperaemia
-within ~24hrs, get proliferation of non-ciliated reserve cells which will try to cover denuded BM
-increased mucous secretion from mucosal glands results in a change from the serous discharge associted with early inflam to a catarrhal discharge
-in severe inflam the exudate may become fibronous and haemorrhagic |
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Term
| Describe serous inflam, in reference to the airways |
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Definition
-Mildest form of inflam - may be seen in early viral inf., mild allergic reactions
-mucosal hyperaemia and oedema
-increased production of fluid from naso mucoserous glands
-clear, watery discharge |
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Term
| Describe catarrhal inflam, in reference to the airways |
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Definition
-Increased production of serous secretions and mucus from mucous glands and goblet cells, compared to serous inflam
-thick, viscous, translucent to slightly turbid discharge with a few inflam cells and cell debris |
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Term
| Describe mucopurlent inflam, in reference to the airways |
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Definition
| Catarrhal inflam with the presence of neutrophils - makes the exudates appear cloudy |
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Term
| Describe purulent /suppurative inflam, in reference to the airways |
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Definition
-Massive emigration of neutrophils
-Often necrosis and sloughing of epithelial cells
-Thick, opaque discharge, may be white, yellowish, green or brown depending on cells/bact. present |
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Term
| Describe fibrinous inflam, in reference to the airways |
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Definition
-Caused by severe injury
-Dramatic increase in vascular permeability and exudation of plasma fibrinogen - coagulates to form fibrin
-May be associated with haemorrhage and tissue necrosis
-Thick, often haemorrhagic discharge with yelllowish, fibrinous strands |
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Term
AFTER 34
Fibrinonecrotic / diptheritic inflam, in reference to the airways |
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Definition
-when the mucosa is covered by an adherent layer
-composed of necrotic, superficial layers of the mucosa, combined w. the inlfam exudate |
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Term
AFTER 34
Pseudomembranous inflam in reference to the airways |
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Definition
Formation of a superficial fibrinous membreane that can be easily peeled off the mucosal surface
Composed of fibrin, necrotic cells, WBCs |
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Term
| Describe how inflam of the upper airways may change over time |
|
Definition
Serous --> Catarrhal --> Purulent
OR
Serous --> Catarrhal --> Fibrinous --> Purulent
At any point may progress to -->healing and resolution
OR -->chronic inflam |
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Term
| Descibe the typical pathological changes associated with chronic inflam of the airways |
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Definition
-Mucosal hypertrophy and hyperplasia (esp. goblet cells)
-Metaplasia of epithelium (squamous metaplasia) and goblet cells in bronchioles (goblet cell metaplasia)
-Infiltration of chronic inflam cells (macro., lympho., plasma cells, +/- neutro., eosino.)
-Fibroplasia/ granulation tissue |
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Term
| Describe a granulomatous inflam of the airways |
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Definition
| Where mucosal inflam is characterized by the presence of an inflam cell infiltrate, with many macro. mixed with lympho. and plasma cells in the mucosa |
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Term
| Nasal / nasopharyngeal polyps |
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Definition
-Diffuse or focal polypoid or pedunculated mucosal nodular thickenings, composed of granulation tissue/fibrous tissue and chronic inflam cells
-covered by normal, hyperplastic or metaplastic epithelium |
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|
Term
| What can lead to the formation of nasal and nasopharyngeal polyps? |
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Definition
| Chronic rhinitis or sinusitis (ie. chronic upper airway inflam) can lead to proliferative changes and thickening of tissues including the formation of polyps |
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Term
AFTER 39
Where do nasal / nasopharngeal polps tend to arise in the cat and horse? |
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Definition
Horse: nasal polyps tend to arise in ethmoid region (progressive ethmoid haematoma)
Cats: Nasopharyngeal polps tend to arise in auditory tube or tympanic bulla/middle ear and may extend into pharynx or ext. ear canal (=aural polyp) |
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Term
|
Definition
Formation of fibrovascular polypoid nodules that protrude into the bronchiolar lumen and interfere with airflow
-can result from severe inflam and organisation of the exudates during healing in the bronchioles |
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Term
| What are the main signs associated with chronic bronchitis and bronchiolitis? |
|
Definition
-increased mucus
-thickeninng of the airway walls/mucosa |
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|
Term
| What are the main sources of increased mucus associated with chronic bronchitis and bronchiolitis? |
|
Definition
-mucus gland hyperplasia (bronchi)
-goblet cell hyperplasia (bronchi)
-goblet cell metaplasia (bronchioles) |
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|
Term
| What are the main causes of thickened airway walls associated with chronic bronchitis and bronchiolitis? |
|
Definition
-mucus gland hyperplasia
-epithelial hyperplasia and metaplasia
-inflam cell infiltrates
-fibrosis
-smooth muscle hypertrophy and hyperplasia |
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|
Term
| What is the most common cause of chronic bronchitis and bronchiolitis? |
|
Definition
| Repeated infections, esp. bacterial inf., parasitic dz. and allergic dz e.g. RAO |
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|
Term
| Consequences to chronic bronchitis and bronchiolitis? |
|
Definition
-Narrowing and obstruction of the airways
-dysponea
-coughing
-incr. resp. noise
-hypoxia
-collapse or over-inflation of lung
-predispostion to chronic bact. inf.
-broncholamacia
-bronchiectasis |
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|
Term
|
Definition
| Weakening of the bronchial cartilage, can result from chronic bronchitis and bronchiolitis |
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|
Term
|
Definition
Destruction of the bronchial wall tissues leading to permanent dilation of the bronchus
-a result of the release of proteolytic enzymes from purulent exudate
-associated with inf. and obstruction of the lumen with exudate
-airway obstruction and atelectasis occurs distally |
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|
Term
| Infectious Bovine Rhinotracheitis (IBR) |
|
Definition
| Highly infectious dz caused by bovine herpes virus 1. |
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|
Term
| Describe the basic dz progression of Infectious Bovine Rhinotracheitis (IBR) |
|
Definition
-Aerosal infection of nasal and conjectival epithelial cells
-Viral replication
-Inflammatory response
-Damage to mucociliary escalator
-Impaired mucosal defences
-Secondary bact. infection
-Influx of neutrophils and so purulent discharge |
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|
Term
Canine Infectious Tracheobronchitis (Kennel cough)
(Bordetella bronchiseptica) |
|
Definition
Lesions of respiratory track of variable severity
-a mucopurulent tracheobronchitis |
|
|
Term
|
Definition
-Caused by streptococcus equi
-colonies the nasopharyngeal mucosa
-purulent nasal discharge
-inf. spreads to LNs
-abscesses within LN can rupture and drain to the surface
-can cause guttoral pouch empyaema if ruptures into guttoral pouch |
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|
Term
| Nasal and sinus aspersillosis |
|
Definition
-most common fungal inf. in UK
-Caused by Aspergillus fumigatus
-mostly seen in dogs, esp. long nosed (may be immunocompromised / other nasal inf.)
-visible fungal plaques on nasal mucosa
-fibrinonecrotic to granulomatous inflam. associated w. mucopurulent or haemorr. nasal discharge
-often causes lysis of turbinate bone |
|
|
Term
|
Definition
-most commonly caused by Aspergillus spp.
-severe inflam - fibrinonecrotic
-deep invasion of tissues can lead to complications
eg. damage to facial nn. (poss. facial, pharyngeal, laryngeal paralysis), erosion of b.v. and haemorr. |
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|
Term
| Name 2 allergy associated dz. of the airways |
|
Definition
Feline ashma (feline allergic bronchitis)
Recurrent airway obstruction (RAO) |
|
|
Term
|
Definition
Presumed to be an acute allergic response (i.e. HS rection)
-bronchial sm. musc. hyper-reactivity causes acute onset dyspnoea and wheezing due to broncho-spasm/constriction
-in chronic cases may see thickening of bronchial wall and evidence of inflam cells |
|
|
Term
| Recurrent Airway Obstruction (RAO) |
|
Definition
-common condition in adult horses
-obstructive condition due to bronchospasm (hyper-responsiveness of the airway sm. musc.) and mucosal inflam and thickening (esp. of bronchioles) |
|
|
Term
|
Definition
(Not fully understood)
Thought to be primarily a HS disorder to inhaled allergens commonly found in mouldy hay or bedding or in stable dust |
|
|
Term
|
Definition
-coughing
-mucopurulent nasal discharge (occludes airways)
-incr. resp rate
-pronounced effort during exp. w. obvious abdominal component - may result in "heave-line"
-wheezing and crackling lung signs on auscultation |
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|
Term
| Progressive atrophic rhinitis in pigs |
|
Definition
-Associated w. infection w. Pasteurella multocida (oft. facilitated by pre-inf. w. Bordetella bronchiseptica)
-B. bronchiseptica = inflam and mild reversible damage to turbinates
-P. multocida = production of osteolytic cytotoxin and progressive destruction of turbinates
-Causes moderate to severe atrophy of nasal turbinates, w. distortion and shortening of snout in advanced cases |
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