Otitis Flashcards
how is the middle ear cavity of the cat different
it is divided by a septum into two distinct regions
which nerve courses near the inner ear and through the middle ear
facial nerve
clinical signs of external ear diseases
head shaking, scratching, otic pain, otic discharge
signs associated with middle ear disease
increased otic pain and head shaking, lethargy, inappetence and pain on opening the mouth
which neurologic signs can be associated with middle ear disease
facial nerve paralysis, horner’s syndrome, problems with parasympathetic nerve to nose and eye
components of horner’s syndrome
enopthalmus, miosis and ptosis
what is seen with damage to the parasympathetic nerve (unilater)
xeromycteria: unilateral dry, hyperkeratotic nasal planum and KCS
what are some peripheral vestibular signs that can be seen with inner ear disease
head tilt, horizontal or rotary nystagmus, circling, falling toward side of lesion
what is the lower translucent part of the tympanic membrane called
pars tensa
what is the dorsal pink, semi-translucent part of the tympanic membrane called (vessels)
pars flaccida
what tests is otic exudate collected for
cytologic exam and bacterial culture
what is otitis externa
an inflammatory condition with or without concurrent infection of the outer ear
define ‘causes’ in regard to otitis externa categorization
factors that incite inflammation directly
primary causes of otitis externa will
create disease in a normal ear
secondary causes of otitis externa will
create disease in an abnormal ear
examples of primary causes of otitis externa
hypersensitivity disorders (atopy, adverse food reactions);
parasites (otodectes);
immune-mediated diseases (pemphigus);
foreign bodies;
endocrine disease;
glandular disorders – sebaceous adenitis, seborrheic disorders
secondary causes of otitis externa
bacteria, yeast, overcleaning, physical trauma
define ‘factors’ in regards to categorization of otitis externa
features of the disease or the pet that contribute to or promote otitis externa
define predisposing factors of otitis externa
factors that increase the risk of development of otitis
present BEFORE development of otitis externa
examples of predisposing factors of otitis externa
conformation, lifestyle (swimming), obstructive lesions, neoplasia and polyps
which breed may have the predisposing factor of large pendulous ears
cocker spaniel or springer spaniel
which breed has the predisposing factor to otitis externa of narrow ear canals
shar pei
which breed has the predisposing factor to otitis externa of excessive hair in the ear canal
poodle
define perpetuating factors of otitis externa
factors cause the disease to continu once established
occur AFTER development of otitis externa
examples of perpetuating factors of otitis externa
otitis media;
progressive pathologic changes to the ear canal
examples of progressive pathologic changes to the ear canal with otitis
edema and erythema;
infiltration of inflammatory cells;
hyperplasia of sebaceous and ceruminous glands;
permanent anatomical changes from calcification of auditory cartilage and fibrosis of dermis and subcutis
steps in assessing a patient with otitis
history; clinical/dermatologic exam; otoscopic exam; ear canal cytologic exam; ear swabs in mineral oil; bacterial C&S; try to identify causes and factors
what are you aiming to assess with an otoscopic exam
patency of tympanic membrane
what do you need to have if doing an ear flush under GA
an inflated endotracheal cuff!
what type of infection is Tris-EDTA useful for
gram-negative infections
what type of infection can Epi-Otic be useful in
bacterial or malassezia
3 types of topical therapy for otitis
glucocorticoids, antibiotics, antifungals
what should be done while a patient is on topical therapy for otitis
monitoring cytologically and adjusting therapy
why must we evaluate the patency of the tympanic membrane
no otic topical treatments are labeled for non-intact tympanic membrane
benefits of using glucocorticoids to treat otitis
antipruritic, anti-inflammatory, antiproliferative and reduce otic secretions
which topical antimicrobial has good activity against pseudomonas
polymixin B
what are systemic glucocorticoids used for with otitis
to decrease stenosis, edema and hyperplasia
when using systemic antimicrobial therapy, what needs to be done for otitis
culture and sensitivity
what is the primary cause of otitis media in cats
infection ascending through the auditory tubes
what 3 clinical signs should be asked about when considering otitis media
sneezing, ocular discharge and nasal discharge
benefits of a myringotomy
both diagnostic (cytology and C&S) and therapeutic (ability to flush)
where is the incision for a myringotomy made
through the caudoventral quadrant of the tympanic membrane
general steps in treating otitis media
access to middle ear (myringotomy);
cytology and bacterial culture of middle ear;
flush tympanic bulla using warmed saline;
reduce inflammation with corticosteroids;
topical antimicrobials +/- systemic;
recheck weekly, may need repeat flushes