Ears, eyes Flashcards
(44 cards)
Which CN provide innervation to the muscles of the middle ear?
– Trigeminal nerve, cranial nerve 5
– Facial nerve, cranial nerve 7
What structure communicate the middle ear with the pharynx?
auditory tube
What is the hypothesized fxn of the guttoral pouch in horses?
diverticulum of the auditory tube that serves as an extracalvarial cooling system d/t the ICA running though the pouch and it can inflate.
What bone makes up the internal ear?
petrous portion of the temporal bone
Describe the anatomy of the middle and internal ear.
External ear pathology?
auricular hypoplasia
normal breed variation
External ear pathology?
auricular hypoplasia
spontaneous
likely hearing loss
External ear pathology
auricular infarction
frostbite
most common neoplasm in the external acoustic meatus? In cats or dogs is it more likely to be malignant?
sebaceous tumors
cats 85%; dogs 60%
What neoplasms are common on the pinna of the ear in dogs vs. cats?
Type of ear neoplasm
aural SCC
External ear pathology?
How is it transferred?
Is the owner does not like the site of this, will it go away on its own?
equine ear papillomas aka aural plaques
>1yr
transferred by fly bites
no
A 4 yr old cat presents with Auricles – bilaterally swollen, erythematous, painful, pruritic, curled. Likely DDX?
What age do we see this?
auricular chrondritis (immune mediated response that targets the cartilage)
>3yrs
A cat presents with a blue/black grape like appearance in the ear. Likely DDX?
The owner wants to know if it is malignant?
feline ceruminous cystomatosis (cystic proliferation of ceruminous glands)
benign
What is this?
Is it more likely a cat or dog?
What are the age ranges for this to develop?
ceruminous gland carcinoma in the ext. acoustic meatus
CAT
Cat: DSH 7-13yrs
dogs: 5-12yrs
Which breeds of dogs are more likely to get ceruminous gland carcinoma?
English bull terrier, Belgian malinois, shih tzu
Where is a ceruminous gland carcinoma most likely to metastasize to first? Is it likely to go other places?
What is the treatment?
parotid l.n.
no
TECA
A <2 yr old cat presents with the following. The owner is concerned its cancer. What do you tell her?
What are two locations the polyp can go?
aural inflammatory polyp
non-neoplastic
nasophaynx; protrude through tympanic membrane
Are aural polyps an external, middle, or inner ear condition?
middle ear
What are the two common types of infections in the equine guttoral pouch? Which is associated with more complications?
■ Bacterial
– Streptococcus equi -Strangles
■ Fungal - guttural pouch mycosis
– Aspergillus sp.
■ Guttural pouch mycosis tends to cause more complications
A horse presents with epistaxis, dysphagia, Horner’s syndrome, facial paralysis. On endoscopy, the picture was obtained. DDX?
What important structures are affected that can account for the clinical signs?
guttoral pouch mycosis
Important structures:
– Internal and external carotid arteries
– CN VII, IX, X, XI, XII
– Cranial sympathetic trunk
What congenital condition is likely in this animal? Why?
deafness- cochleosaccular degeneration
Pigmented neural crest-derived intermediate cells are important for hearing
– If lack pigment -cochloesaccular degeneration -can result in deafness
Dogs breeds associated with hereditory deafness
Australian cattle dogs, Australian sheepdogs, border collies, bull terriers, Norwegian Dunkers, West Highland white terriers, Great
Danes , Great Pyrenees, Lousiana Catahoula Cattle dogs, Old English Sheepdogs, Maltese, and Dachshunds
Anatomy of the eye
