Otic

Question 1

Most ear disease observed in practice involves dermatopathology of the

Answer 1

Most ear disease observed in practice involves dermatopathology of the external ear

Question 2

Answer 2

Dog with otitis externa

Question 3

Otitis Externa

Answer 3

Very prevalent

Secondary bacterial/fungal

Dog with otitis externa

infections

– Staphylococcus, Pseudomonas, Proteus, Malassezia pachydermatis

• Underlying factors

– Allergic skin disease (atopy, food allergy)

– Ectoparasitism

– Foreign bodies

– Conformation – pendulous ears, stenotic acoustical meatus, hair

– Moisture – tropical climate, swimmers • Consequences

– Fibrosis

– Adnexal atrophy and hyperkeratosis

– Osseous metaplasia of cartilage  stenosis of acoustical meastus

– = Constant ear infections

– Middle/inner ear infection

Question 4

Answer 4

Suppurative otitis media in a calf

Question 5

Otitis media

Answer 5

• Portals of pathogen entry
– Extension through perforation of the

tympanic membrane
– Ascension of the auditory tube

• Almost always bacterial
– Pasteurella multocida, Mycoplasma spp.

• Underlying factors
– Functionality of auditory tubes – Immunocompetency

• Consequences
– Inflammation (myringitis) or perforation

Suppurative otitis media in a calf

of tympanic membrane

– Erosion of auditory ossicles

– Horner’s syndrome

– Osteosclerosis of the tympanic bulla

– Formation of inflammatory polyps

– Progression to otitis interna

Question 6

Otitis interna (Labyrinthitis)

Answer 6

• Portals of pathogen entry – Extension from otitis media +/‐

osteomyelitis of petrous temporal bone • Consequences

– Extension through internal acoustic meatus along CNVIIImeningitis

– Vestibular disease – head tilt, nystagmus, ataxia, circling, facial paralysis

– Sensory hair cell loss – permanent hearing impairment (also can be caused by noise, chemical ototoxins, or age‐ related)

Question 7

Answer 7

Aural Plaques

Hyperkeratotic plaques of concave external ear of horses

Thought to be caused by papilloma virus spread by fly bites

Spontaneously resolve

Question 8

Answer 8

Auricular hematoma

• Commonly seen in dogs and pigs, occasionally cats
• Caused by trauma, usually from excessive head shaking centrifugal shearing forces fracture cartilage and lacerate blood vessels
• Underlying ear disease is common

Question 9

Answer 9

Cat with aural SCC

Question 10

What neoplasias are only seen in the ear.

Answer 10

Ceruminous adenoma/ carcinoma

Inflammatory polyps

Question 11

Answer 11

Ceruminous neoplasia

Question 12

Answer 12

Ceruminous neoplasia

Question 13

Ceruminous neoplasia

Answer 13

• Most common neoplasm of the external acoustic meatus of dogs and cats
• Adenomas – more common in dogs
• Carcinomas – more common in cats; invasive and frequent widespread metastasis
• Secondary to chronic inflammation?

Question 14

Answer 14

Inflammatory polyps

Question 15

Inflammatory polyps

Answer 15

• Polypoid masses of middle ear with fibrovascular core, mixed inflammation, and epithelial surface
• Technically non‐neoplastic
• Young cats >>> dogs
• Pathogenesis ‐ chronic inflammation (dogs), congenital defect (cats)