Otitis-Exam 2 Flashcards
What is the shape of the ear canal in SA?
Vertical and horizontal canals with tympanic membrane at end of horizontal
What does the middle ear consist of?
Tympanic cavity, bulla, auditory ossicles, eustachian tube
What does the tympanic membrane consist of?
Pars flaccida and pars tensa
What is the function of the middle ear?
Air vibrations strike eardrum stimulating auditory receptors in inner ear creating SOUND
What does the inner ear consist of?
Cochlear and vestibular apparatus/nerves and semi-circular canals
What are predisposing factors of otitis externa?
Stenosis Hair in canals Pendulous pinnae Swimmer's ear OVeractive glands Polyps Neoplasms
What are primary factors of otitis externa?
Parasites Microbes Atopy Food Drug reactions Contact hypersensitivity Keratinization disorders Autoimmune disease Solar dermatitis
What are perpetuating factors of otitis externa?
Bacteria, yeast, topical reactions, FB Epidermal hyperplasia Hyperkeratosis Dermal edema or fibrosis Lumen stenosis Cartilage mineralization Tympanic membrane changes Middle ear dz
What is the main cause of otitis externa in dogs vs. cats?
Dogs: allergies
Cats: parasites
What are CS of acute otitis externa?
Head shaking –> hematoma
How is acute otitis externa dx?
Otoscopic exam Coffee grounds color: mites Moist, brown: staph or yeast Cream, yellow: gram negative bacT Oily yellow, tan: glandular disorder, hypersensitivity
T/F: Bacterial cultures are needed to dx acute otitis externa?
FALSE- most of the time bacterial infections are almost always secondary to something else
What does ceruminolytic tx do in the ear?
Dissolves wax
Docusate sodium- emulsify wax and lipids
Propylene glycol- epiotic
What agents should be used after cleaning the ears for a drying agent?
Isopropyl alcohol paired with acetic acid, salicyclic acid or benzoic acid
When should you avoid using cleaning solutions that remove debris such as chlorhexidine with drying agents?
When the TM is not able to be assessed
What is the first line Ab used in ears?
Neomycin-polymixin (doesn’t work in pus)
What is a medication that can be used once weekly that can come in handy for aggressive or painful patients?
Poloxamer otic gel
Contains florfenicol/terbinafine/betamethasome acetate
81% of gram negative bacteria are resistant to which drugs?
aminoglycosides and fluoroquinolones
Susceptible to polymixin B
What time period defines persistent otitis externa?
> /= 2 months
What time period defines recurrent otitis externa?
> /= 6 months
What is a major CS that can be seen with otitis media?
Horner’s syndrome or facial paralysis
What are some surgical techniques that can be used for otitis media?
Lateral wall resection
Vertical ear canal ablation
Total ear canal ablation with bulla osteotomy
What is commonly seen in Cavalier King Charles Spaniels and is referred to as “glue” ear?
Primary secretory otitis media
What is a sign that is seen in PSOM (glue ear) that helps with dx?
Bulging pars flaccida
