Surgical Conditions of The Ear Flashcards
what are the main conditions affecting the pinnae?
trauma - lacerations
aural haematoma
neoplasia
what causes aural haematoma?
head shaking causing bleeding between the skin of the ear and the cartilage
when does aural haematoma arise?
usually secondary to other conditions which are causing the dog to shake it’s head
what are the 2 main types of neoplasia seen on the pinna?
squamous cell carcinoma
melanoma
what animals are more prone to neoplasia of the pinna?
white haired
hairless
unpigmented skin
what can be used to protect at risk skin on the pinna from neoplasia?
high factor childs sun cream
what makes up the external ear canal?
vertical and horizontal canals
what is otitis externa?
dermatological disease affecting the ear
what is the most common infection in dogs?
otitis externa
what are the main causes of otitis externa?
immune mediated (allergic)
parasitic infection
poor aeration due to conformation
seconday to middle ear infection (cats)
what is the name of the ear mite of dogs, cats, rabbits and ferrets?
otodectes cynotis
how can poor aeration of the ears be caused and lead to otitis externa?
floppy ears
mechanical obstruction (hair/FB)
neoplasia
chronic inflammatory changes due to previous otitis externa leading to calcification and thickening
when is otitis externa seen in cats?
secondary to middle ear problems
what is the most common condition of the ears in cats?
middle ear issues
what are the main types of neoplasia which affect the ear canals?
squamous cell carcinoma
melanoma
basal cell carcinoma
ceruminous gland adenoma (benign) or adenocarcinoma (malignant)
what is the survival rate for squamous cell carcinoma of the ear canal?
at least one year after surgery
why is squamous cell carcinoma invasive?
may metastasize
if multi centeric further lesions can appear after removal
where is the ceruminous gland found?
sub-dermal layers of the ear canal
what is the role of the ceruminous gland?
helps produce wax
protects ear
what is the issue with melanoma?
more deadly as spreads quickly
what is the most common skin tumor in dogs and cats?
basal cell carcinoma
how severe is basal cell carcinoma?
normally benign but can grow quickly
what are the main middle ear diseases of dogs?
bacterial otitis media
tympanic membrane trauma allowing bacterial infection
tumors are rare unless an extension of another tumor
what is otitis media?
inflammation in the middle ear
what is bacterial otitis media most often caused by in dogs?
development of chronic otitis externa
what are the most common middle ear diseases in cats?
otitis media without otitis externa
neoplasia (rare)
polyps
what is otitis externa in cats normally due to?
primary middle ear disease
what is the most common mass diagnosed in cats?
polyps
what are the areas in cats affected by polyps?
pharyngeal
external ear canal
what causes polyps in cats?
unknown aetiology
what are the 3 common presentations of polyps?
only in bulla (middle ear)
protruding through tympanic membrane
nasopharyngeal
what is caused by polyps protruding through tympanic membrane?
concurrent otitis externa
where do nasopharyngeal polyps grow from?
eustachian tube