Ear Flashcards
What does most ear disease observed in practice involve?
Dermatitis of the external ear
Otitis externa is a (primary/secondary) bacterial or fungal infection.
SECONDARY!
What are some underlying factors that contribute to external ear infections?
Allergies
Ectoparasites
Foreign body
Conformation (pendulous ears, stenotic acoustic meatus, hair)
Moisture
How can an external ear infection cause conditions in which infections become constant?
Osseous metaplasia of cartilage and stenosis of the ear canal create a conformational change that predisposes the animal to more ear infections, and the cycle continues.
What are common bacteria implicated in otitis externa?
Pseudomonas, Staphylococcus, Proteus, Malassezia pachydermatis
T/F: An animal can get a middle ear infection as a consequence of otitis externa.
TRUE
What are the portals of entry for bacteria into the middle ear?
Perforation in the tympanic membrane
Ascension of the auditory tube
2 common bacterial species implicated in middle ear infections:
Pasteurella multocida
Mycoplasma spp
T/F: Middle ear infections can’t cross into the inner ear.
FALSE
What ear infections can cause Horner’s syndrome, osteosclerosis of the tympanic bulla, inflammatory polyps, erosion of the auditory ossicles, and inflammation/perforation of the tympanic bulla?
Middle ear infections (otitis media)
In cases of otitis interna (labyrinthitis), what is the portal of pathogen entry?
Extension from otitis media, with or without osteomyelitis of petrous temporal bone
If an inner ear infection travels through the internal acoustic meatus along CN VIII, what can result?
Meningitis
What are 3 consequences of otitis interna?
Meningitis
Vestibulitis
Sensory Hair Loss
A condition in which trauma fractures cartilage and lacerates blood vessels in the ear. Common with excessive head shaking.
Auricular hematoma
If a dog comes in with an auricular hematoma, what will you look for as a potential primary factor?
Underlying ear infection
