Unit 2: 4 - Head & Neck Flashcards
What salivary glands do dogs have?
Parotid, mandibular, sublingual (mono/polystomatic), zygomatic
What salivary glands do cats have?
Parotid, mandibular, sublingual (mono/polystomatic), zygomatic, molar
What are 3 indications for surgery of the salivary glands?
- Mucoceles
- Tumors
- Trauma
What SG tumor is common in dogs?
parotid
What SG tumor is common in cats?
Mandibular
What is a mucocele?
Collection of saliva in tissues surrounded by granulation tissue
What are the 5 types of mucoceles?
Cervical, sublingual (ranula), pharyngeal, complex, zygomatic/parotid/molar
What are mucoceles caused by?
Unknown
What is the most common CS for a mucocele?
Asymptomatic
What diagnostics are done when a mucocele is suspected?
Cytology, imaging, histopath
How are mandibular and sublingual SGs excised?
- Incise capsule
- Dissect
- Ligate and transect duct caudal to lingual nerve
- Drain or marsupialize mucocele
- Histopath - rule out neoplasia
How is the parotid SG excised?
By tedious dissection
How is the zygomatic SG excised?
By transecting the arch
What are 3 things that can happen after a SG excision?
Recurrence, seroma, infection
What is the prognosis for a SG excision?
Good with mucocele but varies with a tumor
What structures make up the external ear?
Pinna, auditory meatus (vertical and horizontal canals)
What structures make up the middle ear?
Tympanic membrane, auditory ossicles, auditory tube (Eustachian)
What structures make up the inner ear?
Semicircular canals, cochlea
What are indications for surgery of the ear?
Aural hematomas, otitis, tumors/masses, trauma
What is the cause for an aural hematoma?
Trauma, irritation
What is the cause for otitis?
Derm-related (allergies, parasites, bacteria, yeast, immune-mediated dz, FB, conformation)
What are CS for aural hematomas?
Swollen fluid filled mass, head shaking, scratching
What are CS for otitis?
Foul odor, pain, rubbing/scratching ears, discharge, canal narrowing/proliferation, hearing loss, neuro signs
What are the components of an otic exam?
+/- sedation, otoscope, swab (cytology, C&S)
What is the preferred imaging for the ear?
CT
What are 6 procedures that can be done surgically to the ear?
- Pinna drainage
- Pinnectomy
- Lateral ear canal resection
- Vertical ear canal resection
- Total ear canal resection (with lateral bulla osteotomy)
- Ventral bulla osteotomy
How is an aural hematoma treated?
Treat cause –> remove clots & fibrin, lavage –> place a teat cannula, active drain, “S” incision, and/or bandage
What are complications that can happen from an aural hematoma?
Can recur, cauliflower
T/F: No bandage is needed for an aural hematoma when a teat cannula is placed
True
Which way are sutures oriented around an “S” incision?
vertically, parallelling major vessels and obliterating dead space
What tumors are common in the ear?
SCC, melanoma, mast cell
What are 3 things that can be done to mitigate trauma?
- Repair (appose epith edges and exclude cartilage)
- Partial pinnectomy (cosmetically contour and appose epith edges)
- Bandage (primary, concurrent)
What are 2 benefits to doing a lateral ear canal resection?
- Improves drainage and ventilation
- Facilitates topical treatment
Lateral ear canal resections should be done before _____ and _____.
proliferation, calcification
What are 3 indications for a total ear canal resection?
Irreversible hyperplasia, stenosis, calcification
What are indications for a ventral bulla osteotomy?
Polyps, otitis media (w/o externa), problems post TECA
What part of a cat’s bulla is the largest?
ventromedial compartment
What is the promontory part of the cat’s bulla?
Plexus of postganglionic sympathetic nerves
What is the purpose of a ventral bulla osteotomy?
Increased exposure and drainage
What are 3 complications associated with the lateral and vertical ear canal resections?
- Inadequate drainage
- Persistent otitis and progression
- Dirty tumor margins
What are 7 complications that can happen after total ear canal resection and ventral bulla osteotomy?
- Hemorrhage
- Infection/abscess
- Facial n. paralysis
- Deafness
- Vestibular dysfunction
- Horner’s syndrome (cats)
- Fistula/otitis media - remnants
What are 3 indications for surgery of the thyroid/parathyroid glands?
Tumors, adenomatous hyperplasia, cysts
What CS are associated with thyroid carcinomas in dogs?
Cervical mass, dysphagia, laryngeal dysfunction, cough, dyspnea, exercise intolerance, hemorrhage
What CS are associated with parathyroid tumors?
PU/PD, vomiting, weakness, constipation, lethargy, inappetance, cystic calculi, bone and joint pain
What CS are associated with adenomatous hyperplasia in cats?
Unthrifty, weakness, muscle tremors, ataxia, incoordination, muscle atrophy, breathless, collapse
Where does the thyroid get its blood supply?
Common carotid and brachiocephalic trunk
Where do the parathyroid glands get their blood supply?
Cranial thyroid artery
What should be done in a thyroidectomy?
It is a bilateral procedure but should preserve one parathyroid
What are 6 complications that can arise from surgery of the thyroid/parathyroid?
- Hypothyroidism
- Hypocalcemia (rare if unilateral)
- Hemorrhage
- Laryngeal paralysis
- Dysphagia
- Recurrence
What is the most common thyroid tumor and what is the prevalence?
Thyroid carcinoma - 90%
How often are thyroid carcinomas metastatic and how often are they functional?
Metastatic = 40-80%
Functional = 10%
What is the risk to taking a thyroid biopsy?
High risk of severe or fatal hemorrhage
What is the prognosis for surgical removal of thyroid adenomas?
Excellent - curative
What is the prognosis for surgical removal of carcinomas?
Depends on mobility, size, and stage
3 years if movable
6-12 months if invasive
3 months if untreated
Bilateral thyroid tumors are ___ times more likely to metastasize.
16
What are adjunct treatments for thyroid tumors?
I131 = cats
Radiation
Chemo
What is primary hyperparathyroidism caused by?
Excess excretion of PTH
What is secondary hyperparathyroidism caused by?
Chronic renal failure, diet imbalance
What does excess PTH result in?
Increased Ca and P release from bone –> Ca resorption and P excretion by kidneys & Ca and P absorption in the intestines
How hoes hypercalcemia cause PU/PD?
Elevated Ca levels interfere with proper functioning of the renal tubule cells that normally respond to ADH –> increased urination –> increased thirst and dehydration
How can hyperparathyroidism be diagnosed?
Measure persistent ionized hypercalcemia, inappropriate or high PTH, no PTHrp
What % of patients have hypocalcemia after parathyroid surgery?
33%
When do we treat for post op hypocalcemia?
- Total Ca <8.0 mg/dL
- iCa <0.8 - 0.9 mmol/L
- CS = face rubbing, muscle tremors, convulsions
How can we treat acute hypocalcemia?
10% Ca gluconate
How can we treat long term hypocalcemia?
Calcitriol, Ca, maintain serum Ca at low/low normal
What are the LNs of the head and neck?
Mandibular, parotid, retropharyngeal, superficial cervical (prescapular)
Branchial and pharyngeal cysts have an _____ lining.
epithelial
Where are branchial cysts?
Lateral or dorsolateral neck
Where are Rathke’s cleft cysts?
Nasopharyngeal obstruction
Where are thymic cysts?
Mediastinal or SQ neck
Where are thyroglossal duct cysts?
Ventral midline
