Diseases of the upper airways

Question 1

What is included in the upper airways?

Answer 1

Nasal cavities
Sinuses
Pharynx
Guttural pouch

Question 2

Give examples of developmental abnormalities of the upper airways

Answer 2

Cleft palate
Guttural pouch tympany
Brachycephalic airway syndrome

Question 3

What causes a cleft palate and what does this lead to?

Answer 3

Failure to close palatine shelves

Aspiration of food

Question 4

What is guttural pouch tympany?

Answer 4

Nasopharyngeal opening defect - lead to air in guttural pouch

Question 5

What are the consequences of guttural pouch tympany?

Answer 5

Air causes pressure in guttural pouch

Dyspnoea, dysphagia and aspiration pneumonia

Question 6

What is brachycephalic airway syndrome?

Answer 6

Combination of problems: stenotic nares, elongated soft palate and everted laryngeal saccules

Question 7

What are the consequences of brachycephalic airway syndrome?

Answer 7

Obstructed airways
Cyanosis
Syncope

Question 8

What can cause inflammatory conditions of the URT?

Answer 8

Irritants and allergens (pollen, dust, fomites)
Foreign bodies
Parasites
Infectious agents

Question 9

What are the most common inflammations of the URT?

Answer 9

Rhinitis
Sinusitis
Pharyngitis

Question 10

What is a circulatory disturbance of the URT?

Answer 10

Epistaxis - nosebleed

Question 11

What can cause epistaxis?

Answer 11

Inflammation, infection, trauma, neoplasia, clotting defects

Question 12

How is acute inflammation classified?

Answer 12

By type of exudate:
Serous 
Catarrhal 
Fibrinous 
Purulent

Question 13

What are the 2 main responses of the URT to acute inflammation?

Answer 13

Vasodynamic changes - redness, swelling, exudate

Increased serous/mucous secretions

Question 14

What is the mildest form of acute inflammation?(remember: classified by exudates)

Answer 14

Serous

Question 15

Describe the exudate present with serous acute inflammation. What can cause this serous exudate?

Answer 15

Clear, watery discharge (no cells)

Increased production from mucoserous glands, mucosal hyperaemia and oedema

Question 16

After serous acute inflammation, what is the next type of exudate? Describe the exudate

Answer 16

Catarrhal

Viscous, mucoid

Question 17

What causes catarrhal exudate? What cells does it contain?

Answer 17

Increased mucoserous secretions

Few numbers of inflammatory cells

Question 18

Describe fibrinous exudate

Answer 18

Thick
Fibrinous
Haemorrhage

Question 19

What causes fibrinous exudate?

Answer 19

Severe injury
Causes dramatic increase in vascular permeability
+/- necrosis

Question 20

What is the most severe form of acute inflammation (remember: classified by exudate)?

Answer 20

Purulent (suppurative)

Question 21

Describe purulent exudate. Does it contain cells?

Answer 21

Thick
White/green brown
Often accompanied by necrosis
Yes: many inflammatory cells (mainly neutrophils) and sloughing of epithelial tissues

Question 22

What are the pathological changes present with chronic inflammation of the URT?

Answer 22

Mucosal hyperplasia
Epithelial metaplasia
Chronic inflammation cells
Fibroplasia

Question 23

What cells are seen with chronic inflammation?

Answer 23

Macrophages
Lymphocytes
Plasma cells

Question 24

Epithelial metaplasia is seen with chronic inflammation of the URT. Describe the epithelium changes

Answer 24

Ciliated columnar epithelium replaced by stratified squamous

CC-SS

Question 25

Name an inflammatory condition of the URT often seen in horses and cats

Answer 25

Nasal and nasopharyngeal polyps

Question 26

What are the 2 different outcomes of acute inflammation?

Answer 26

``` Healing and resolution Chronic inflammation (if insult persists) ```

Question 27

Where do nasal/nasopharyngeal polyps arise and extend to in cats?

Answer 27

Arise in auditory tube or tympanic bulla | Extend into pharynx or external ear canal

Question 28

Neoplasia in the URT is most common in which age group of dogs? What % of these neoplasms are malignant?

Answer 28

Middle aged to elderly | 80%

Question 29

What breeds have increased risk of URT neoplasia?

Answer 29

Bassets Shetland sheepdog and Old English sheepdog Airedales German shorthair pointer

Question 30

What neoplasms can be seen in the URT?

Answer 30

Squamous cell carcinoma Adenocarcinoma Chondrosarcoma, osteosarcoma, fibrosarcoma Lymphoma

Question 31

What is a squamous cell carcinoma?

Answer 31

Cancer of lining of epithelium

Question 32

What is an adenocarcinoma?

Answer 32

Cancer of glands in epithelium

Question 33

What is a chondrosarcoma and osteosarcoma?

Answer 33

Cancer of cartilage | Cancer of bone

Question 34

What is cancer of connective tissue called?

Answer 34

Fibrosarcoma

Question 35

What is a lymphoma?

Answer 35

Cancer of the lymphoid tissue

Question 36

Give examples of a bovine viral agent associated with URT inflammation

Answer 36

Infectious bovine rhinotracheitis (IBR)

Question 37

What virus causes infectious bovine rhinotracheitis?

Answer 37

Bovine herpes virus 1

Question 38

What factors can affect IBR? (Infectious bovine rhinotracheitis)

Answer 38

Overcrowding | Stress

Question 39

Describe the pathogenesis of IBR

Answer 39

Inhaled and infects nasal and conjunctival epithelial cells Virus replicates and disseminated throughout respiratory tract Inflammatory response

Question 40

What are the symptoms of IBR?

Answer 40

Conjunctival and nasal hyperaemia Serous or catarrhal exudate Severe cases - fibrinous inflammation and necrosis of mucosa

Question 41

How does IBR lead to secondary infections? How are these resolved?

Answer 41

Damaged mucociliary escalator Impairs defence Causes secondary infections Influx of neutrophils and purulent discharge Cell mediated immunity response causes healing within 10-14 days

Question 42

Give examples of equine URT viruses

Answer 42

Equine herpes virus 1&4 | Equine influenza virus

Question 43

Give examples of feline URT viruses

Answer 43

``` Feline calicivirus (flu) Feline herpes virus 1 (flu) ```

Question 44

Give examples of canine URT viruses

Answer 44

Canine distemper Canine adenovirus 2 Canine parainfluenza virus

Question 45

Give an example of a bacterial agent associated with URT inflammation in horses

Answer 45

Streptococcus equi | strangles

Question 46

Describe the pathogenesis of strangles

Answer 46

Infection from contaminated feed, air or exudate Colonisation of nasal mucosa Initially serous nasal discharge becomes purulent Rapid spread to LNs

Question 47

Which lymph node is primarily involved in strangles? What happens if this ruptures?

Answer 47

Retropharyngeal | Infection spreads into surrounding tissues including guttural pouch, can cause empyema

Question 48

Give an example of a bacterial associated with URT inflammation n pigs

Answer 48

Pasturella multocida

Question 49

What does Pasturella multocida cause in pigs?

Answer 49

Progressive atrophic rhinitis | Severe atrophy of nasal turbinates - shortening and distortion of snout

Question 50

Pasturella multocida in pigs can be facilitated by pre-infection with what agents?

Answer 50

Bordatella bronchiseptica | Porcine cytomegalovirus

Question 51

Give an example of a fungal agent associated with inflammation of the URT. What species can this be in?

Answer 51

Aspergillus fumigates | Dogs, horses and birds

Question 52

What does aspergillus fumigates cause in horses?

Answer 52

Guttural pouch mycosis | Leads to severe unilateral inflammation and necrosis

Question 53

What are the complications of Aspergillus fumigates infection in horses? (Think of adjacent structures

Answer 53

Cranial nerve damage | Erosion of internal carotid artery and haemorrhage (can be fatal)