Lecture 16 - Respiratory 2

Question 1

Why can nasal disturbances in horses have severe consequences?

Answer 1

Horse are obligate nasal breathers

Question 2

What are some generic upper respiratory tract signs that may be seen?

Answer 2

1. Sneezing 2. Coughing 3. Discharge 4. Sturter and strider 5. Halitosis (bad breath) 6. Muzzle pain

Question 3

What are the primary and secondary lesions that are typically seen with BOAS (Brachycephalic airway syndrome)?

Answer 3

Primary = stenotic nares, elongated soft palate, hypoplastic trachea, redundant pharyngeal folds Secondary = everted sacculus (secondary to stenotic nares), tracheal collapse (hypoplastic trachea), GI signs (e.g. regurgitation and vomiting lead to esophagitis)

Question 4

How do BOAS breeds normally die?

Answer 4

In hot weather or vigorous exercise they get hyperthermia and then collapse.

Question 5

Name the feature in image below (all charactersitcs of BOAS) and state whether it is a primary of secondary lesion:

Answer 5

1. Stenotic nares (primary)
2. Elongated soft palate
3. Everted sacules (secondary to stenotic nares)
4. hypoplastic trachea that has lead to tracheal collapse

Question 6

Are URT neoplasia normally malignant or benign what is the name of the condition shown below?

Answer 6

Usually malignant and its a squamous cell carcinoma (very errosive)

Question 7

What is the condition shown in the dog below and what are some clinical signs that you might expect to see?

Answer 7

Canine nasal adenocarcinoma - sturter, dysnopsea, open mouth breathing, maybe pyrexia and hyperthermia?

Question 8

What is the name of the condition that is shown below?

Answer 8

Nasal osteosarcoma

Question 9

What is the name of the condition that is shown below?

Answer 9

Nasal polyps and cysts - these can occur in any species

Question 10

Do Rhinitis and sinusitis normally occur together or by themselves? Outline the basic pathogenesis for these conditions:

Answer 10

Rhinitis and sinusitis usually occur together

1. Initial irritant, fungi or pathogen can cause disease on its own
2. Disease can disrupt protective mechanism –> colonisation by opportunistic organisms

Question 11

Briefly describe the different presentations of rhinitis and sinusitis:

Answer 11

1. Serous - fluid
2. Catarrhal - mucous on membranes
3. Purulent - pus that is bright green to yellow
4. Fibrinous - lots of fibrin
5. Granulomatous - white tan nodules

Question 12

What are the main causes of rhinitis and sinusitis?

Answer 12

1. Immune mediated/idiopathic
2. Bacterial
3. Fungal
4. Viral
5. Protozoan parasites
6. Metazoan parasites
7. Algal

Question 13

What is the method of entry for equine viral rhinitis and sinusitis? Provide 2 examples of viral agents in horses and explain how they appear:

Answer 13

Aerogenous entry

EHV-1, EHV-2 (herpes) - mild respiratory disease

Equine influenza - commonly, self limiting - not too much damage, highly contagious

Generally only seen at necropsy with secondary bacterial infections + opportunistic bacteria

Question 14

What are some examples of bacteria that can cause bacterial equine rhinitis and sinusisitis? Briefly explain the conditions and pathology they produce and how they are transmitted:

Answer 14

Streptococcus equi equi (strangles) - common in young horses produces supprative rhinitis and lymphadenitis (internally –> bastard strangles) - air droplets containing bacterium. Pyogranulomatous inflammation in affected organs.

Burkholderia mallei (glanders) - zoonotic, transmitted via horse meat, ingestion of contaminated feed and water - pyogranolamotous nodules that ulcerate

Burkholderia pseduomallei - (Melioidosis/pseudoglanders) - simmilar to above

Question 16

Names the virus and condtion shown below and breifly explain the clinical importance of it:

Answer 16

Infectious bovine rhinotracheitis (Rednose) causes by BoHV-1. Combines with mannheimia haemolytica to produce pneumonia, Generally not severe but can see dysnopsea due to obstrcution of airways by exudate.

On necropsy - severe hyperaemia, focal necrosis of mucosa, fibrinous inflammation

Question 17

Name the parasite in the image below and state the likely pathological effects of it:

Answer 17

Oestrus ovis (nasal bots) - fly deposits first stage larvae into nostrils causing irritation, inflammation, erosionm, airway obstruction + predispose to colonisation by bacteria

Question 18

Name the condition below and explain the pathogenesis of it:

Answer 18

Atrophic rhinitis - inflammation and atrophy of nasal turbinates - causes deviation of the nasal septus

Pathogenesis: Co-infection of Bordetella bronchiseptica and pasturella multocida - the toxigenic strain produce potent cytotoxins –> inhbition of osteoblastic activity and promote osteoclastic re-absorption of nasal bones

Question 19

Name the condition shown below given the cause is unknown and state a possible aetiology given that this in the cause we had a dolichocephalic dog (and a German Shepard at that!). Why is this particular breed prone to this particular viral pathogen? What other viruses are common in general canine respiratory conditions?

Answer 19

Idiopathic lymphoplasmacytic rhinitis - Aspergillus - common in dolichocephalic dogs - particularly German Shepards (IgA deficiency)

Most common pathogens - B. bronchiseptica, parainfluenza, adenovirus 2, distemper virus

Question 20

Provide an example of a viral, bacterial and fungal cause of rhinitis and sinusitis in felines and breifly describe the pathology of them:

Answer 20

Viral:

• FHV-1 (Feline viral rhinotracheitis) - predisposes to secondary pnuemonia and calcivirus
• FCV (Feline Calicivirus rhinitis) - wide ranging symptoms

Bacterial:

• Clamydophilia felis (feline chlamydiosis ) - persistent respiratory infection with cats - conjunctivitis and serous/mucopurulent rhintis

Fungal:

Nasal cryptococcus- environmental fungus that some cats and dogs can harbour

Question 21

Name the condition below and name the cause:

Answer 21

Equine ethmoid haematoma - common in older horses, chronic progressive with an unknown cause

Question 22

What are some generic larynx and trachea clinical signs that may be seen?

Answer 22

• Coughing
• Wheezing
• Sturter and strider

Question 23

What species is a reduction in tracheal patency often observed in?

Answer 23

Most commonly seen in toy, minature and brachycephalic breeds of dogs - seen as dorsoventral flattening of the tracheal membrane

Question 24

What is an example of a neoplasm that might be found in the larynx and/or trachea?

Answer 24

Tracheal chondroma or osteochrondroma

Layngeal rhabdomyoma

Question 25

For the lesion below in the calf state the cause and pathophysiology of it:

Answer 25

Caused by Fusobacterium necrophorum. It produces several exotoxins and endotoxins after it gains entry through viral lesions or traumatic entry. It can cause death from severe toxaemia or overhwelming bacteraemia

Question 26

Below is a canine laynx and trachea what clinical condition does this cause and what are three infectious agents that may cause it?

Answer 26

Kennel cough can be caused by any combination of Bordetella bronchiseptica, canine adenovirus II, canine parainfluenza virus

Question 27

Below in an infected guttural pouch, What mycotic organism might have produced this change and what as some potential sequelae?

Answer 27

Organisms could be aspergillus or streptococcus equi equi (strangles)

Sequelae: rupture of the carotid branch and exsanguination

Question 28

What is the cause of the pathology seen below?

Answer 28

Idiopathic laryngeal hemiplagia