Sinus Disease & Epistaxis

Question 1

Which muscles dilate the nares at exercise in horses?

Answer 1

Nasolabialis muscles (facial nerve VII)

Question 2

Causes of primary sinusitis?

Answer 2

• Bacterial – NB consider S equi var equi
• Fungal (Aspergillus)

Question 3

Causes of secondary sinusitis?

Answer 3

Usually secondary to dental disease

Question 4

Which teeth are associated with the sinuses in the horse?

Answer 4

• PM 4 and M1(part) are usually located in rostral maxillary sinus
• M1, M2 and M3 are usually located in caudal maxillary sinus

Question 5

What signs would you expect to see with dental disease in the first and second cheek teeth?

Answer 5

• PM2 and 3 are not usually associated with paranasal sinuses (1^st and 2^nd cheek tooth)
• So if we have dental disease in these teeth
• The pus building at the apices of these teeth will cause facial distortion and enlargement/facial swelling as the primary finding

Question 6

What diagnostics can be used for sinus disease?

Answer 6

• History (purulent (odorous) nasal discharge (unilateral))
• Physical examination
• Percussion over sinuses to detect fluid
• Nasal endoscopy
• Sinoscopy
• Radiography
• Advanced imaging, esp CT

Question 7

Which sinuses are easiest to make trephine holes into for sinoscopy?

Answer 7

The frontal sinus or caudal maxillary sinuses

Question 8

How do paranasal sinus cysts tend to present?

Answer 8

• Usually in young animals
• Expansive fluid filled lesions
• Can cause facial distortion if they get very large

Question 9

How are paranasal sinus cysts generally diagnosed?

Answer 9

• Radiography - soft tissue opacity throughout sinuses +/- gas / fluid line (but can be obscured by the secondary disease, e.g. secondary sinusitis)
• Often get secondary sinusitis as normal drainage is obscured and so fluid builds up

Question 10

Treatment and prognosis of paranasal sinus cysts?

Answer 10

• Surgical removal via a frontonasal flap
  
  • Post-operative care as for sinusitis (promote drainage and antibiotics)
• Good prognosis - recurrence rare if you remove all of the cysts

Question 11

How does primary bacterial sinusitis tend to develop?

Answer 11

• Usually younger horses
• Opportunistic bacteria, often Strep. sp.
• Sequel to URT infection, related to poor drainage

Question 12

Clinical signs of primary bacterial sinusitis?

Answer 12

• Purulent unilateral (usually) nasal discharge, not foul smelling
• Lymph node enlargement (sometimes)

Question 13

Diagnosis of primary bacterial sinusitis?

Answer 13

• Radiography - gas/fluid lines
  
  • Pretty much in horizontal straight line
• Need to determine whether it is a primary disease or a secondary disease

Question 14

Treatment of primary bacterial sinusitis?

Answer 14

• Treatment to establish drainage and eliminate infection
• Promote mucociliary clearance: Mucolytics, inhalations, feeding at floor level, exercise and antibiotics can all be used
• Many resolve spontaneously

Question 15

How would you manage primary bacterial sinusitis that is not responding to medical management?

Answer 15

• Irrigation and drainage via trephine (or pin)
• Frontal/maxillary flap if inspissated pus (hard, accumulated infection) to physically remove it - can be done standing

Question 16

Prognosis of primary bacterial sinusitis?

Answer 16

Good

Question 17

When does secondary bacterial sinusitis tend to occur?

Answer 17

• Usually older horses
• Most often secondary to dental disease e.g. dental fracture, periodontal disease (periapical abscessation)

Question 18

Diagnosis of secondary bacterial sinusitis?

Answer 18

• Physical examination (esp look for systemic diseases e.g. PPID)
• Oral examination and dental assessment
• Endoscopy (discharge from nasomaxillary opening)
• Radiography (fluid lines and dental disease)
• CT to evaluate tooth roots directly.

Question 19

Treatment of secondary bacterial sinusitis?

Answer 19

• Treat primary disease
  
  • Remove diseased teeth
  • Pack oro-nasal fistulae
  • Irrigation and antibiotics

Question 20

What other conditions might you see in the paranasal sinuses?

Answer 20

• Fungal granulomas
• Ethmoidal haematomas
• Squamous cell carcinoma
• Other neoplasia is less common

Question 21

How does secondary mycotic sinusitis develop?

Answer 21

Occurs as a result of sequestra, chronic antibiotic administration, surgery, underlying debilitating disease

Question 22

Clinical signs of mycotic sinusitis?

Answer 22

• Typically a destructive malodorous condition, that destroys the normal structure of the paranasal sinuses
• Nasal discharge
• +/- haemorrhage

Question 23

Diagnosis of mycotic sinusitis?

Answer 23

• Sinoscopy/endscopy
• Radiographs may be unremarkable
  
  • Especially if early mycotic disease
  • If chronic may see significant changes due to structural damage

Question 24

Treatment of mycotic sinusitis?

Answer 24

• Eliminate underlying cause (or treat – eg PPID)
• Physical lavage, then…
• Lavage with topical antifungal agents (e.g. Enilconazole)
• Prolonged treatment (4-6 weeks)

Question 25

Prognosis of mycotic sinusitis?

Answer 25

Good prognosis if treated adequately and not significant structural damage

Question 26

Clinical signs of mycotic rhinitis?

Answer 26

Malodorous purulent / sanguinous discharge

Question 27

How does mycotic rhinitis occur?

Answer 27

* Occurs from within the nasal cavities themselves * *Aspergillus fumigatus* * In plants inc hay and straw. * Secondary to trauma?

Question 28

Diagnosis and treatment of mycotic rhinitis?

Answer 28

* Serology is unreliable. * Topical treatment with nystatin or natamycin (powders) * Or endoscopically flush the cavities

Question 29

Potential sources of bilateral epistaxis?

Answer 29

* Lungs * Exercise induced pulmonary heamorrhage – variable amounts (esp. racehorses/performance horses) * Lung neoplasia – variable, usually small amounts * Pharynx * Trauma, foreign body – variable, usually small amounts * Guttural pouch mycosis - large amounts

Question 30

Potential sources of unilateral epistaxis?

Answer 30

* Pharynx * Guttural pouch mycosis - large amounts * Sinus * Mycotic sinusitis – usually small amounts * Trauma – usually small amounts * Nasal Cavity * Progressive Ethmoidal Haematoma – usually a slow trickle * Clotting abnormalities – usually slow and intermittent * Trauma

Question 31

How does iatrogenic epistaxis usually occur?

Answer 31

* Usually a result of passing stomach tube into middle meatus * Should always go via the ventral meatus * Can be a significant amount of blood

Question 32

How should you manage iatrogenic epistaxis?

Answer 32

* Care with passing tubes, well lubricated and care when removing the tubes too. * Will stop with time * Always warn owners that it may happen before passing anything * Hold head up * Avoid drugs to lower blood pressure (eg ACP)

Question 33

Which structures can be affected by gutteral pouch mycosis?

Answer 33

* Usually affects internal carotid (medial compartment) * may be external or maxillary artery (lateral compartment) * cause tissue trauma and erodes into the blood vessels, usually not massive haemorrhage initially * may be a bilateral condition - check other GP

Question 34

Clinical signs of gutteral pouch mycosis?

Answer 34

* Epistaxis: usually 1-3 episodes mild bleeding before the entire vessel ruptures - FATAL * Neurological dysfunction: facial nerve, laryngeal or pharyngeal paralysis, vagal signs

Question 35

Diagnosis of gutteral pouch mycosis?

Answer 35

* Diagnosed most commonly by endoscopy * haemorrhage from guttural pouch ostia * DO NOT ENTER POUCH - REFER AND LET THEM DO IT! * Radiography * If you can see fluid lines in GP indicates there may be significant haemorrhage

Question 36

Immediate management of gutteral pouch mycosis?

Answer 36

* Emergency due to potential for fatal haemorrhage * Very spontaneous and die very fast * **REFERRAL** * (Temporary cut down and occlusion of carotid can be used as in severe haemorrhage)

Question 37

Treatment of gutteral pouch mycosis?

Answer 37

* Optimal treatment - surgical * Ligation and balloon occlusion of affected artery (on both sides of the fungal lesion) * Retrograde flow occurs therefore balloon occlusion recommended

Question 38

How does PCV alter in the horse following acute blood loss?

Answer 38

* Initially…Loss of whole blood so **no change in PCV or TP in first 4 hours** * After this, splenic contraction in response to hypoxia causes **increase in PCV, and increase in circulating RBC** * Then, fluid recruited from Extracellular fluid, causing **decline in TP and possible decline in PCV 4-6h** * PCV changes not appreciated for 12-24 hrs

Question 39

Why do we have to take a bone marrow aspirate or biopsy in horses to classify their anaemia?

Answer 39

Horses do NOT release immature RBCs (stay in bone marrow)

Question 40

How does a bone marrow sample differentiate anaemia in the horse?

Answer 40

* Determination of MYELOID cells * Determination of ERYTHROID cells * Ratio between them different in different anaemias

Question 41

How would you get a bone marrow sample in the horse?

Answer 41

* Hollow needle, around a 12G, firm and hollow trochear * Drive into sternum to sample the bone marrow * Examined by clinical pathologist to determine the anaemia type.