PATHOLOGY - Oropharyngeal and Cervical Disease Flashcards
What are the seven main differentials for cervical swellings?
Sialocoele
Abscess
Cyst
Granuloma
Neoplasia
Lymphadenopathy
Haematoma
What are the four salivary glands found in small animals?
Parotid
Zygomatic
Mandibular
Sublingual
What is a sialocoele?
A sialocoele is where there is a leakage of a salivary gland or duct resulting in an accumulation of saliva in the submucosal or subcutaneous tissues, with the location of the swelling dependent on the salivary gland or duct affected
What is the main clinical sign of a sialocoele?
Non-painful, fluctuant swelling
Where can sialocoeles be located?
Cervical sialocoeles
Pharyngeal sialocoeles
Zygomatic sialocoeles
Mandibular sialocoeles
Submandibular sialocoeles
Where are sialocoeles most commonly seen and which salivary gland/duct is affected?
Cervical sialocoeles are most common and caused by the sublingual salivary gland/duct
Which sialocoele can be an emergency?
Pharyngeal sialocoeles can be an emergency as they can cause airway obstruction
Which salivary gland/duct causes pharyngeal sialocoeles?
The parotid salivary gland/duct can cause pharyngeal sialocoeles
What is an additional clinical sign of a zygomatic sialocoele?
Exopthalmus is a key clinical sign of a zygomatic sialocoele
Note these are caused by the zygomatic salivary gland/duct
What are some additional clinical signs of a sublingual sialocoele?
Dysphagia
Cervical swelling
What are the potential causes of a sialocoele?
Idiopathic (most common)
Trauma
Sialoliths
Neoplasia
Foreign bodies
What are sialoliths and how can they cause sialocoeles?
Sialoliths are salivary stones which can cause a blockage and rupture, leading to a sialocoele
Which dog breeds are prone to developing idiopathic sialocoeles?
German Shepherds
Poodles
Australian Silkys
Daschunds
How do you diagnose a sialocoele?
Assess the clinical signs (the dog should be non-painful at palpation)
Fine needle aspirate (FNA) the swelling
Sialogram (very challenging)
Contrast CT (expensive and not widely available)
Describe the gross appearance of a fine needle aspirate (FNA) appear if the swelling is a sialocoele
The fine needle aspirate (FNA) should appear viscous and honey-coloured if the swelling is a sialocoele
How should a fine needle aspirate (FNA) of a sialocoele appear on cytology?
A fine needle aspirate (FNA) of a sialocoele should have few inflammatory cells and erythrocytes, with a proteinaeceous background on cytology. You can also stain for mucin using Periodic acid–Schiff (PAS) stain, and this would be diagnostic
What is a sialogram?
A sialogram is contrast radiography of the salivary glands and ducts. This is very challenging as it requires the injection of a contrast medium into the appropriate salivary duct
How should you treat a sialocoele?
Sialoadectomy which is the surgical removal of the affected salivary gland/duct
This is referral surgery
Why is it important to remove the mandibular and sublingual salivary gland together?
The mandibular and sublinguial salivary glands are attached
What is the prognosis for sialoadectomy?
Excellent prognosis with less than 5% change of recurrence
Why is drainage not a recommended treatment for a sialocoele?
Draining is not a recommended treatment for a sialocoele as there is a high rate or recurrence as you are not treating the root of the problem, and there is a risk of introducing infection with repeated drainage
What is the most common cause of cervical swellings in dogs?
Oropharyngeal penetrating injury
What is the most common cause of oropharyngeal penetrating injuries in dogs?
Sticks
So, if dogs present with cervical swellings, make sure to thoroughly quiz the owner on whether their dog plays with sticks
Which signalement is most prone to oropharyngeal penetrating stick injuries?
Medium sized dogs are over-represented for oropharyngeal penetrating stick injuries most likely due to breeds that have innate chewing/retreiving behaviours
How do oropharyngeal penetrating stick injuries cause clinical signs?
Oropharyngeal penetrating stick injuries cause local trauma to the oropharyngeal area and inoculation of foreign material and bacteria which track into the tissues
When is an oropharyngeal penetrating stick injury classified as acute?
An oropharyngeal penetrating stick injury is classed as acute between 1 to 7 days
What are the potential clinical signs of an acute oropharyngeal penetrating stick injury?
Pain
Pyrexia
Dysphagia
Gagging/retching
Bloody saliva
Oropharyngeal haemorrhage
Subcutaneous emphysema
Pyothorax/mediastinitis
What is subcutaneous emphysema?
Subcutaneous emphysema is when air accumulates within the subcutaneous tissues
How can an oropharyngeal penetrating stick injury cause a pyothorax/mediastinitis?
If the penetrating stick injury causes damage to or tracks through the oesophagus, this can introduce debris and bacteria into the thorax and mediastinum which can progress to a pyothorax and mediastinitis
What is the prognosis for dogs that present with pyothorax/mediastinitis following an oropharyngeal penetrating stick injury?
Very poor prognosis
How do you diagnose an acute oropharyngeal penetrating stick injury?
Assess history and clinical signs
Oropharyngeal examination under general anaesthetic (can include oesophagoscopy)
Radiographs of the head, neck and thorax
Which areas within the oropharynx are common sites for oropharyngeal penetrating stick injuries?
Corners of the mouth
Tongue
Under the tongue
Hard palate
Soft palate
Why is it important to do radiographs of the head, neck and thorax when investigating an oropharyngeal penetrating stick injury?
It is important to radiograph the head, neck and thorax to look for evidence of gas within the tissues which suggests the oropharyngeal penetrating stick injury has tracked into the tissues. Gas in the cervical tissues can indicate oesopageal damage so it is very important to endoscope the oesophagus (oesophagoscopy). Radiographs also allow to you assess for pneumothorax which can also occur with a tracking oropharyngeal penetrating stick injury
How do you treat acute oropharyngeal penetrating stick injuries?
If you find a penetrating tract in the oropharynx or evidence of gas in the tissues, carry out exploration of the oropharynx and remove any foreign material through flushing/lavage
A rigid endoscope is very useful if available
When is an oropharyngeal penetrating stick injury classified as chronic?
An oropharyngeal penetrating stick injury is classified as chronic if it has been present for over 7 days or if the initial treatment has been unsuccessful
What is the typical clinical presentation of a chronic oropharyngeal penetrating stick injury?
Painful, firm, enlarged cervical swelling which may have a draining sinus tract, and the dog may or may not be pyrexic
How do you diagnose a chronic oropharyngeal penetrating stick injury?
History
Clinical signs
Fine needle aspirate (FNA) the swelling
Thorough oropharyngeal exam under general anaesthetic
Radiography of the head, neck and thorax (assess for gas in the tissues indicating tracking injuries))
What should you be aware of when carrying out an oropharyngeal exam for a chronic penetrating stick injury?
After a few days, there may not be a penetrating wound present as the mouth heals and closes wounds very quickly
How do you treat chronic oropharyngeal penetrating stick injuries?
If you find a penetrating tract in the oropharynx (you might not) or evidence of gas in the tissues, carry out exploration of the oropharynx and remove any foreign material and infection through flushing/lavage and debridement. Also carry out an enbloc resection of the swelling if possible (i.e if it is an abscess)
A rigid endoscope is very useful if available
(T/F) Cleft palate is congenital and cannot be acquired
FALSE. Cleft palate can be congenital or acquired
What are the two congenital causes of cleft palate?
Inherited
Intrauterine trauma/stress
What should you advise breeders if they bring in a puppy or kitten with cleft palate?
Cleft palate is inherited so you should advise breeders not to breed from that genetic line
What is the typical presentation of neonates with cleft palate?
Failure to thrive
Milk discharging from the nostrils
Dysphagia
Clinical signs of aspiration pneumonia
What is the prognosis for congenital cleft palate?
Congenital cleft palate may require euthanasia or can be surgically corrected within the first 3-4 months of age however this can be challenging
This is referral surgery
What are the aetiologies behind acquired cleft palate?
Trauma
Neoplasia
Chronic infection
What are the most common traumatic causes of cleft palate?
Cats that have fallen from a height
Chewing electrical cords
Foreign bodies
(T/F) Cleft palate is your primary clinical concern if a patient has been chewing electrical cords
FALSE. If a patient has been chewing electrical concerns, your primary concern is neurogenic pulmonary oedema, the cleft palate can be resolved later
How do you treat acquired cleft palate?
Surgical repair of the cleft palate
Which features make a cleft palate sutiable for surgical repair in first opinion practice?
Acute trauma
Midline cleft palate
Acquired via trauma
Unlikely to require flaps
Tension free closure should be achievable
Why is it important to surgically repair a cleft palate as soon as possible?
If you delay surgical repair of a cleft palate, the maxillary bones making up the hard palate will fuse in an open position which would lead to a bone defect dorsal to the soft tissue repair, increasing the risk of wound dehiscence
What are the goals of cleft palate surgery?
- Repair the soft tissue deficit but direct suturing of the mucosa
- Stabilise the maxilla with compression of the hard palate to encourage closure of the palate defect using wires
What is the most appropriate suture material for surgical repair of a cleft palate?
Polyglactin 910
Why is polyglactin 910 the most appropriate suture material for repairing a cleft palate?
Absorbable
Short lasting
Doesn’t cause intra-oral irritation
Which suture pattern can be used to repair the mucosa during cleft palate surgery?
Simple continuous pattern
How can you encourage closure of the hard palate for cleft palate surgery?
Place wires around the carnassial teeth and around the canines in a mattress or cruciate pattern to push the palatine bones together. The wires can be removed after 3 weeks
What factors should you consider for post operative care of cleft palate surgery?
Analgesia
Nutritional support (however will likely eat even with wires)
Will require another short anaesthetic to remove the wires
Keep patient house bound to avoid anything snagging the wire
What are the differential diagnoses for an oronasal fistula?
Severe periodontal disease
Toot extraction
Neoplasia
Trauma
Foreign body
What is the typical clinical presentation of an acute oronasal fistula due to tooth extraction?
Epistaxis
Visualisation of the nasal cavity
What is the typical clinical presentation of a chronic oronasal fistula?
Unilateral food containing nasal discharge
Sneezing
How do you treat an oronasal fistula?
You correct an oronasal fistula with a labial flap. It is important to ensure there is no tension at the flap or the surgery will not be successful
What are the five most common oral neoplasms in dogs?
Ameloblastomas (epulids) (these are benign)
Malignant melanoma
Squamous cell carcinoma
Fibrosarcoma
Periodontal ligament tumour
Which breed of dog is prone to oral ameloblastomas (epulids)?
Boxers
What are the two most common oral neoplasias in cats?
Squamous cell carcinomas
Fibrosarcoma
Where are oral squamous cell carcinomas most commonly located in cats?
Under the tongue
What are the typical clinical signs of oral neoplasia?
Abnormal prehension of food
Blood tinted saliva
Dysphagia
Ulceration
Halitosis
Which surgical procedures are often required to treat oral neoplasia?
Maxillectomy
Mandibulectomy
This is referral surgery
What should you be aware of when counselling owners about treatment for oral neoplasia?
The surgical removal of oral neoplasia requires bony resection to achieve margins through a maxillectomy or mandibulectomy depending on the location of the mass. Owners need to understand that the prognosis for these surgeries is good however they require the removal of a portion of their pets face/jaw
