Unit 2: Feline Otology Flashcards
What are some differences between the feline ear and canine ear?
Feline external canal doesn’t have a deep “trap”, is of a smaller diameter, is less hairy, and has a bony spetum that splits the ventral cavity
When looking at the tympanic membrane of the cat, what structure is not visible that you can normally see in the dog? Why?
Round window - the bony plate is in front of it
How does the feline malleus compare to the dog?
It is straighter in cats
How can you determine if the feline TM is intact?
Look for the malleus
Why are diagnostic procedures more difficult to perform in cats?
They have smaller canals (equiment limitations) and a body septum (can’t get into bulla)
What is the #1 primary factor of otitis in cats?
Parasites (Otodectes)
What are some other primary factors of otitis?
Allergic, infectious/inflammatory, idiopathic, neoplastic
What are secondary/perpetuating factors of otitis?
Malassezia, bacteria (G+ > G-), proliferative changes, otitis media
What diagnostics are done in cats for otitis?
Same as dogs:
History, PE, otoscopy, cytology, C&S, biopsy, imaging
What type of restraint is best for otoscopy in cats?
Minimal (but consider chemical restraint if there is work to be done);
Lay arms down along both sides of the cat, hold up the jaws with your forefingers, place thumbs on the back of the head by the occipital crest, can massage the throat a bit
What are 3 therapies used to treat Otodectes?
Clean ears
Topicals (Ivermectin, milbemycin, pyrethrins, fluralaner)
Systemic (selamectin, moxidectin, Ivermectin)
What organism usually contributes to feline otodemodicosis?
Demodex cati
T/F: Feline otodemodicosis is associated with generalized demodicosis.
False
How is otodemodicosis treated?
There is no single drug to treat; but any drug that treats Otodectes should work for this
What topical meds can be used to treat otodemodicosis?
Pyrethrins, thiabendazole, ivermectin, milbemycin
What ppour-on insecticides can be used to treat otodemodicosis?
Selamectin, moxidectin, fluralaner
How does allergic otitis in cats compare to dogs?
Cats don’t get clinical otitis as often as dogs;
Incidence is unclear but one study found that only 16% of atopic cats had allergic otitis
What is allergic otitis in cats associated with?
Atopic dermatitis and adverse food reactions
What are the clinical manifestations of allergic otitis in cats?
Pruritus (rubbing, scratching), ceruminous otitis
Malassezia otitis in cats is secondary to _____.
allergy
What things can contribute to bacterial otitis in cats? What is the prevalence?
Prevalence of bacterial otitis is very low;
Seen with inflammatory polyps and neoplasia
Other than Malassezia and bacteria, what things can cause infectious otitis in cats?
Mycoplasma otitis media, idiopathic feline proliferative otitis
What condition would we be worried about if we saw Horner’s Syndrome in a cat?
otitis media
What diagnostic is recommended when we see vestibular signs due to middle ear involvement?
CT
What is bacterial otitis most often associated with?
Aural polyps, otitis media, neoplasia
When do we see ceruminous cystomatosis?
In cats with low grade, chronic otitis externa
What do you see with ceruminous cystomatosis?
Dilated ceruminous glands, hyperplasia, cysts with blue-black watery fluid and debris
What are ways to treat ceruminous cystomatosis?
Control infections and inflammation, ID primary factor (difficult), cautery of lesions, surgical removal/laser ablation of cysts
What does post ablation therapy of ceruminous cystomatosis consist of?
Appropriate topical and systemic antimicrobials, topical GCs or pred/methylpred
When do we recheck ceruminous cystomatosis after treatment?
7 days
Where do inflammatory polyps originate?
Middle ear epithelium, possibly from auditory tube epithelium;
Rarely from the external ear canal
Inflammatory polyps are often associated with _____ cats, often post _____.
young, upper respiratory infections
What are the chief complaints of Inflammatory polyps?
Ear discharge, head shaking, scratching ears, stridor, gagging, nasal discharge
How are Inflammatory polyps diagnosed?
May be difficult to see due to exudation, but is usually unilateral and have a characteristic visual appearance.
Can use rads or CT
What types of polyps are easiest to pull?
Older ones - they are more fibrosed;
Early polyps are friable and more likely to fragment
How are polyps managed?
Control infection and remove the polyp
What are the options for polyp removal?
Traction avulsion, traction avulsion with surgical exposure, through the video-otoscope, ventral bulla osteotomy
What is traction avulsion?
Physically grasping and pulling the polyp
What is the correct technique for traction avulsion?
Twist and pull (“bend and snap”)
What is the appropriate therapy post-removal for polyps?
Topical antimicrobial at time of avulsion, systemic antimicrobial for 30 days, systemic GC, topical therapy
What is the key to preventing relapse of polyps?
systemic GC administration
What are complications associated with traction avulsion?
Persistent infection, Horner’s syndrome, recurrence
What cats usually have neoplasia of the ear?
Older cats
What clinical signs are associated with neoplasia of the ear?
Head shaking, pruritus, malodor; may resemble aural polyp with secondary infection and suppurative exudate
What is needed to confirm diagnosis of neoplasia of the ear?
Biopsy
What therapies are available for neoplasia of the ear?
Laser ablation if early;
OR total ear canal ablation
What are DDx for neoplasia of the ear?
Infectious (not related to polyps), or neoplasia
What types of neoplasias are common in the ear?
Ceruminous adenoma, ceruminous adenocarcinoma, SCC
What neoplasia of the ear is easier to differentiate from the others?
SCC
What is the prevalence of feline proliferative and necrotizing otitis?
It is rare
What cats get proliferative and necrotizing otitis?
Kittens or adults
What is the pathogenesis of proliferative and necrotizing otitis?
T cell mediated apoptosis of KCs (etiology unknown)
What lesions are seen with proliferative and necrotizing otitis?
Dry, tightly adherent crusts at the base of the pinnae (usually bilateral);
May affect skin elsewhere
What drug class is used for treating proliferative and necrotizing otitis?
Calcineurin inhibitors
What is the treatment of choice for proliferative and necrotizing otitis?
Tacrolimus
What are the most common ear problems of the cat that are not like those of the dog?
Otoacariasis, cystomatosis, aural polyps, otitis media
