Ear disease and surgery Flashcards
What are the two parts of the tympanic membrane
Pars tensa = thin, clear bit we see
Pars flaccida = dorsal part which can bulge downwards if fluid accumulates in middle ear and be mistaken for ear neoplasia
What is erythroceruminous otitis
Most common form of otitis
See redness with yellow/brown ceruminous discharge
Pruritic; not really painful
Staphs on cytology +/- malassezia
What organisms is suppurative otitis assocaited wtih
Pseudomonas, proteus and other gram -ves
What does a cobblestone appearance of ear suggest
Chronic pathological changes due to poorly managed ear disease over month s
= hyperplasia of ceruminous glands, thickebing of dermis and epidermis causing canal stenosis
Chronic fibrosis
When do we do cytology or C/S in ear disease
Always cytology
Culture and sensitivity sometimes; but not that useful because antibiotic ocnentrations very different in ear compared to in vitro prediction s
What is the primary cause in 80% of ear disease
Atopic dermatitis
Which animals get otodectes
What to remember
How to treat
Esp puppies/kittens
Treat with selemectin or canaural
Remember it is zoonotic potentially
What endocrine disease can be implicated as a primary cause of ear disease
Hypothyroidism due to altering
What neoplasia can be a primary cause of ear disease
Ceruminous cystomatosis which is non-neoplastic; can progress to adenocarcinoma
What considerations must we have before applying otic polypharmaceutical
Ask owner to turn head away since these are ototoxic
Tympanic membrane may be ruptured; not meant to use
What medications can be ototoxic
All can be
Esp aminoglycosides, cisplatin, furosemide
What antibiotics have lower ototoxic potential so good to go for
Fluoroquinolones, ceftazidime (cephalosporin)
What cleaning product is good to use in ear due to low ototoxic potential
Triz EDTA
Can be an antibacterial glush and potentiate antibitoic activity
Good against pseudomonas
Neutralising solution e.g between low pH ear cleaner and antibiotics
Options for assessing integrity of tympanic membrane
Visual assessment; not very accurate
Spruells neede; if hit bone = bulla so not bouncing on trampoline of tympanum
Advanced imaging
POsitive contrast canalograpu pst semsotove
None are 100% accurate
WHat is the blood supply to the ear like
Large supply via auricular arteries off the carotid
Pathogenesis of aural haematmooa
Head shaking due to otitis externa or parasitic infection leads to damage to blood vessels, cartilage fracture and fluid leakage ot form haematoma
Treating acute haematoma aural
Needle drain +/- corticosteroid injectino
Must recurrence common
How to treat chronic aural haemotoma
Need an incisional drainage surgery to remove dead space and provide drainage
Involves placing non-absorbable mattress suture full thickness sutures to take the skin down to the cartilage
- Keep in place for 2 weeks
- Can use stents to present sutures being placed too tightly
What is actinic keratosis
Pre-neoplastic change for aural SCC
Treatment options for aural SCC
Surgical excision with 1-2 cm margins
Pinnectomy may be needed to achieve this
What cartilages do the vertical vs horizontal ear canal involve
Vertical = auricular
Horizontal = annular
Difference in bulla between dogs and cats
In dogs, single, small cavity not externally palpable
Cats: larger bulla with incomplete bony septum splitting bulla into small dorsolateral compartment and large ventromedial comparmtnet
Symp nerves more exposed in cat
What structures msut we be aware of during ear surgery
Facial nerve; passes outside bony skull ventral to ear canal
Retroauricular vein
Parotid salivary gland
How commonly are ear canal neoplasias malignant in dogs/cats
Cats; 90% malignant
Dogs; 60%
