otitis

Question 1

What dog breeds are predisposed to otitis externa?

Answer 1

• Cocker spaniels (pendulous ears)
• Shar peis (stenotic canals)
• Brachycephalic breeds (stenotic horizontal canals)

Question 1

List the most common PRIMARY causes of otitis externa in dogs

Answer 1

• Parasites (otodectes, demodex, etc)
• Atopic dermatitis
• Adverse food reactions
• Malassezia
• Endocrine dz: HAC/Cushings, HypoT
• Foreign body

Question 2

What is the most common pathogen associated with secondary fungal infection from otitis externa?

Answer 2

Malassezia

Question 3

Where is the tympanic membrane found in the ear?

A. Inner Ear
B. Middle Ear
C. External Ear

Answer 3

B. Middle Ear

Question 4

Which dog breed has stenotic ear canals, making them predisposed to otitis?

Answer 4

Shar peis and brachycephalics

Question 5

What is the most common pathogen causing secondary bacterial infection in the ear canal?

Answer 5

Staphylococcus pseudintermedius

Question 6

How does stenotic ear canals affect the normal function of the external ear?

Answer 6

• External ear has a self-cleaning mechanism by epithelial turnover and migration that allows cerumen and debris to be removed
• Stenotic canals make it harder to effectively clear canal of debris

Question 7

List the gross changes that can be seen with chronic ear disease

Answer 7

• Epidermal folds
• Stenosis
• Hyperpigmentation
• Lichenification

Question 8

What is the drug of choice to treat otitis externa from malassezia?

Answer 8

• Miconazole topically

Question 9

What is the drug of choice to treat stenotic ear canals?

Answer 9

• Prednisolone for 14 days!!
• Goal is to reverse the stenosis and inflammation in order to get a better look in canal

Question 10

You perform a cytology on an ear swab from a pug and see a mix of cocci and rods. Which antimicrobial would you avoid using?

Answer 10

• Florfenicol / Claro otic solution (only effective against cocci, not effective for rods)

Question 11

What is the drug of choice for a patient with rods on cytology from an ear swab?

Answer 11

• Gentamicin (targets cocci, rods, AND pseudomonas)

Question 12

List common anti-inflammatories used in the treatment of otitis externa

Answer 12

• Mometasone
• Betamethasone
• Triamcinolone
• Dexamethasone
• Prednisolone
• Hydrocortisone

(glucocorticoids are mainstay anti-inflammatory agents)

Question 13

List the benefits of ear cleaning

Answer 13

• Removes pus and debris
• Increases efficacy of topicals
• Allows visualization of epithelial lining
• Allows visualization of tympanic membrane
• Makes patient more comfortable

Question 14

What is the protocol for ear cleaning when the tympanic membrane is ruptured?

Answer 14

Only saline should be used in the middle ear or if tympanic membrane is ruptured

Question 15

Secretory otitis media is found in which breed of dogs?

Answer 15

Cavalier King Charles spaniels

Question 16

How does the anatomy of the middle ear in cats differ from dogs?

Answer 16

• Cats tympanic membrane is divided into 2 compartments
• Makes it difficult to flush and medicate the inner ear of cats

Question 17

List the main clinical signs seen in patients with otitis media

Answer 17

• Head tilt
• Difficulty swallowing/gulping
• Facial paralysis
• Xeromycteria (dry nose)

Question 18

How do you treat a patient with otitis media from a pseudomonas infection?

Answer 18

• Glucocorticoids to reverse stenosis
• 2-3 deep flushes under GA
• Analgesics
• Gentamicin or Silver Sulfadiazine

Question 19

What antibiotics can be used for otitis media from Pseudomonas infection?

Answer 19

• Aminoglycosides (Gentamicin)
• Silver Sulfadiazine
• Fluoroquinolones
• Polymyxin B
• Chlorhexidine
• Triz EDTA

Question 20

What is the treatment plan for a patient presenting with an aural hematoma?

Answer 20

• Surgical insision, drainage and suture
• Drainage and penrose tubing
• Drainage and glucocorticoid instillation
• Drainage using aural hematoma tube and local anesthetics

Question 21

A king charles spaniel presenting with a head tilt and difficulty when eating and drinking. On otoscopic exam you see a bulging tympanic membrane. Most likely Ddx?

Answer 21

Secretory otitis media