Special Senses Part 2 Flashcards
describe the differences between trichiasis, distichiasis, and ectopic cilia. which is the most damaging?
trichiasis: hairs in normal position but are misdirected to contact the cornea, causes corneal irritation
distichiasis: abnormally positioned eyelash coming from the opening of the meibomian glands, usually no corneal damage (very mild irritation)
ectopic cilia: abnormally positioned eyelash coming FROM the palpebral conjunctiva, severe corneal damage!
trichiasis is common in which dog breeds?
bracycephalic breeds like pugs and bulldogs
describe the differences between entropion and ectopion
entropion: inward rolling of the eyelid causing corneal irritation (a type of trichiasis)
ectropion: outward rolling of the eyelid margin (think basset hound with droopy lower eyelids) causing chronic keratitis/conjunctivitis
what is shown here in the top photo, and then the bottom photo?
top: entropion, eyelid rolling in
bottom: ectropion, eyelid rolling out
prolapse of the 3rd eyelid has a common name of _______ and it is most common in ______
cherry eye, dogs
what is the most common tumor of the canine eyelid?
meibomian gland tumors
Your client brings you their new resuce dog, Andy. You examine Andy’s eye and you find this. The client is concerned. What do you tell them?
I would tell them that this is most likely a meibomian gland tumor and they are almost always benign so there is nothing to worry about. I would tell him we can surgically remove it or simply leave it alone and Andy will be fine.
what is the second most common eyelid tumor in dogs? What are some of the characteristics of this tumor?
eyelid melanocytomas
usually benign
can look very similar to meibomian gland tumors grossly
how do conjunctival melanomas in dogs usually behave?
they are malignant with frequent metastasis, usually found in the bulbar conjunctiva. these are not very common in dogs
this is a dog eye. What kind of tumor do you suspect?
conjunctival melanoma
squamous cell carcinoma of the eye is common in what animal(s)? Where does this tumor arise from
horses in cattle
arises from the conjunctiva
where is squamous cell carcinoma usually found on a cow or horse? What is this type of tumor associated with?
on the 3rd eyelid
associated with UV light exposure
what are 3 common gross features of squamous cell carcinomas that help with diagnosis?
usually it will be on non pigmented skin, will be ulcerated, and inflammed
what is the common name of squamous cell carcinoma in a cow?
cancer eye
the left is a cow, the right is a horse. what kind of tumor is this? (same for both photo)
s
squamous cell carcinoma
what is the name of the glnds that produce earwax?
ceruminous glands
otitis externa is most common in ____ and is the result of what 3 factors?
dogs
predisposing factors (conformation or breed)
primary causes (skin conditions, ectoparasites)
secondary causes (bacterial or fungal infections)
if a dog has chronic otitis and shakes its head consistently, what can happen?
the dog can develop a hematoma because the shaking of the head causes trauma to the blood vessels in the pinna and causes hemorrhage into the pinna
what kind of dogs are more prone to developing aural hematomas?
large breed dogs with droopy ears
what is the fancy name for a mite infestation? Who commonly gets this?
otoacariasis
kittens
a client brings you a older horse and you see depigmented plaques/warts on the concave surface of the ear. What does this horse have and what is the significane?
these are aural plaques caused by equine papilloma virus. these are distinct from other papilloma warts because they affect older horses. they do not regress but have no clinical significance
this a horse ear. what are you seeing here?
aural plaques caused by equine papilloma virus
what is an “ear tooth” in a horse?
an equine dentigerous cyst, they are congential cysts at the base of the ear often with a fistula connecting to the surface. they are from tooth stem cells being placed in an abnormal location. They cause no pain or problems to the horse
this is a horse ear. what are you seeing here?
a dentigerous cyst
what causes ear tip necrosis?
it is from ischemic injury specifically infarcts. Examples: frost bite, vasculitis, immune mediated, viral, toxicities, etc
this is from a calf. what is this?
ear tip necrosis (you can see sharp lines of demarcation)
the most common external aucostic meatus tumors in dogs and cats are _______. How do these tumors behave?
tumors of the ceruminous glands
these are usualy malignant esp in cats
this is the ear of a cat. Given this mass is locally invasive, what is this tumor most likely?
a creuminous adenocarcinoma, a malignant tumor
otitis media is common in what animal(s)? what are clinical signs?
ruminants and pigs
signs: droopy ears, head tilt, frequently occurs in conjunction with respiratory disease
what classic pathogen is associated with otitis in cattle and what pathogen for pigs?
cattle: mycoplasma bovis
pigs: pasturella multocida
this is the tympanic bullae. what is this?
suppurative otitis media
if an animal has penumonia, where should you also look for disease?
look in the ears, specifically the tympanic bullae
what is this disease? the photo on the left is normal and the one on the right is diseased
otitis media
What is Horner’s syndrome? What are some clinical signs?
result of loss of innervation to the eye which can be secondary to otitis media
clinical signs: constricted pupil, eye pulled back, head tilt, prolapsed 3rd eyelid, anisocoria, dilation of blood vessels on the affected side
what disease is this?
horner’s syndrome ( right side of the cat is affected, left side of this photo)
nasopharyngeal polyps occur in what animal? how do they relate to the ear?
young cats
can also have/cause otitis externa or media with one of these
guttural pouch disease involes which two common etiologies?
streptococcus equi equi (strangles)
aspergillus sp
these are in the guttural pouch of a horse. what is the name for these?
chondroids (pus stones from a chronic strep infection)
what is temporohyoid osteoarthropathy of horses? what are clinical signs
the joint between the proximal hyoid bone and the temporal one can become degernative and undergo bony proliferation and fusion of the joint
clinical signs: abnormal behavior like ear rubbing and problems chewing, severe acute vestibular signs or facial nerve damage if the joint fractures
what are the two types of vestibular disease?
peripheral vestibular disease (involving internal ear sensory receptors)
primary vestibular disease (involving the brainstem and cerebellum)
what causes peripheral vestibular disease in geriatric dogs?
it is often idiopathic, is acute onset, and starts to show improvement 2-3 days without treatment
what are 3 differentials for a rabbit with a head tilt?
otitis media
trauma
encephalitozoon caniculi
rabbits can get this strange gram positive fungi which targets the brain, kidney, and eyes. What is it called?
encephalitozoon caniculi
what are the 3 body systems that encephalitozoon caniculi infects in rabbits?
eye, kidney, and brain
What would you see on histology of a a kidney from a rabbit with a E. caniculi infection?
granulomatous inflammation
what gross lesions will you see with a rabbit with E caniculi?
pitting of the renal cortex and cataracts in the eyes
this is a rabbit kidney. what are you suspicious of?
encephalitozoon caniculi
