Lecture Note

1. Affection of salivary gland
Dr. Bikash Puri
Assist. Professor
Nepal Polytechnic Institute, Chitwan
lecture note

2. Mucoceles (Salivary cysts)
• Salivary mucocele (or sialocele) is an accumulation of saliva in the submucosal
or subcutaneous tissues after damage to the salivary duct or gland capsule.
• This is the most common salivary gland disorder of dogs.
• Although any of the salivary glands may be affected, the ducts of the sublingual
and mandibular glands are involved most commonly.
• Saliva often collects in the intermandibular or cranial cervical area (cervical
mucocele).
• It can also collect in the sublingual tissues on the floor of the mouth
(sublingual mucocele or ranula).
• A less common site is in the pharyngeal wall (pharyngeal mucocele) or lower
eyelid (zygomatic mucocele).
lecture note

3. Cervical mucocele
lecture note

4. Ranula
A ranula is a thin walled linear swelling that results from ruptured sublingual or
mandibular salivary ducts below the oral mucosa next to the tongue or rupture of the
polystomatic portion of the sublingual gland.. Rannulas have been reported in cats.
lecture note

5. Causes
• Usually, the exact cause is not determined, but a developmental
predisposition in dogs has been suggested
• Traumatic injury
• Blockage
• Rupture of the duct or capsule (with damage of parenchyma) of the
sublingual, mandibular, parotid, or zygomatic salivary gland.
Note: the leakage of the salia into the surrounding tissue and their reaction
with local tissue may lead to development of salivary cyst or ranula.
lecture note

6. Signs
• A mucocele is detectable as a soft, fluctuant, painless mass
• Pain or fever may be present if the mucocele becomes infected.
• On aspiration of light brown or blood-tinged, viscous saliva can be detected.
• Usually, careful palpation with the animal in dorsal recumbency can determine
the affected side;
• if not, sialography may be helpful.
• .
lecture note

7. • A ranula may not be seen until it is traumatized and
bleeds.
• A pharyngeal mucocele can obstruct the airways and
result in moderate to severe respiratory distress.
• A zygomatic mucocele may result in exophthalmos or
enophthalmos, depending on its size and location
lecture note

8. Treatment
• Ranula
– Incise the cyst to drain out the contents .
– Cyst wall is then touched with Tinct. Iodine to destroy its lining and
prevent further accumulation of fluid.
– Finally, suture the mucous membrane of the ranula to the oral
mucosa. Use a multfilament synthetic absorbable suture of 3-0 size.
lecture note

9. Surgical technique (Cervical
Mucocele)
• Removal of the mandibular and sublingual salivary glands
• First positioning the dog in lateral recumbency with the affected side uppermost.
• The neck and jaw should be positioned slightly obliquely and towels or sand bags
placed under the neck to elevate the surgical site for better visualization of the
bifurcation of the jugular vein.
• The incision is made from the ramus of the mandible cranially to the bifurcation of
the jugular vein caudally ; occlusion of the jugular vein prior to incision will
facilitate visualization of landmarks. Dissection is carried into the capsule of the
mandibular and sublingual salivary glands. An intracapsular dissection commences
and the glands are removed from the capsule.
lecture note

10. lecture note

11. lecture note

12. • The ducts of the mandibular and sublingual salivary glands are followed craniomedially to the
mandible.
• If you are on the correct side, you should encounter saliva from the mucocele oozing into the incision or
a dilation of the duct can be visualized.
• The ducts are followed as far cranially as possible and ligated or stripped out to complete the
resection An incision is made at the most dependant point of the cervical mucocele (when the animal is
standing!) and a penrose drain is placed to facilitate postoperative drainage of saliva Platisma muscle,
subcutaneous tissues and skin are closed in a routine fashion and
• The drain is removed two to three days postoperatively. If the salivary glandular tissue has an unusual
appearance at the time of resection, it should be submitted for histopathologic evaluation.
lecture note

13. Salivary fistula
• Salivary fistula is an uncommon problem that can result from
trauma to the mandibular, zygomatic, or sublingual salivary glands.
• Wounds of the parotid gland are most likely to develop a fistula.
• Parotid duct injury may be the result of a traumatic wound (eg, bite
wound), abscess drainage, or prior surgery in the area with
iatrogenic rupture.
• The constant flow of saliva prevents healing, and a fistula develops.
lecture note

14. Clinical signs
• Saliva dribbles down form the wound causing
excoriation in the area.
• Losses of excessive saliva may lead to
dehydration and ingestion
• Presence of high grade of inflammation
sometime it lead to inflammation to parotid
gland itself.
lecture note

15. Treatment
• After proper controlling and achieving anaesthesia, a
circular incision should be made along the fistular tract.
• Care should be taken not to cut facial artery and vein
• The stenson’s duct is isolated. Due to pressure of
accumulated saliva in duct, diameter becomes many times
larger than normal.
• The blunt needle or catheter is passed inside the duct
toward s the glandular part
• A counter irritant solution is injected inside the duct to
destroy the function of the gland.
• The duct is ligated after withdrawing the catheter or needle
• The wound is debrided and closed in routine manner.
lecture note

16. Excision of the parotid gland
• It is indicated only when there is high grade of infection.
• For this, an oblique incision of 15-20 cm is given bellow the base of the ear
extending along the caudal border of the vertical ramus
• The parotid gland is ligated or clamped
• The skin and parotido-auricularis muscle are reflected to expose the gland.
• The duct along with infected gland should be removed intact to avoid
contamination of the area.
• Provide drainage and the skin wound closed in routine manner.
lecture note