Parotid gland enlargement and hypersialosis in a dog

Parotid Duct Ectasia in a Dog

A 3yr old spayed female Brittany was referred with a cylindrical mass on the right side of her face. Three months earlier, a small stone embedded in the right parotid duct was noted and removed through a ductal incision by the referring veterinarian. At referral, the dog's general physical condition was normal except for a cylindrical mass on the right cheek. Skull radiographs showed a possibly retained sialolith or dystrophic mineralization within the previous surgical site. Aspiration of the mass yielded a thick, yellow/tan, mucopurulent fluid. Cytology of the fluid demonstrated degenerative neutrophils without bacteria. The cylindrical mass was excised with a carbon dioxide laser. The caudal end of the mass was connected to the parotid salivary gland and the rostral one-third of the mass tapered to a point. The caudal end of the mass was ligated with 3-0 polydioxanone and excised immediately rostral to the ligation. Histopathology revealed that the mass was parotid duct ectasia. The dog completely recovered with some mild temporary facial paresis and had no recurrence of parotid duct ectasia at 4 mo follow-up. The case report describes a dog with an unusual parotid salivary duct ectasia caused by parotid duct sialolith removal.

Surgical management of parotid salivary duct rupture secondary to non-iatrogenic trauma in a dog

A 3-year-old French bulldog presented for evaluation of recurrent swelling and a fistula on the right cheek after a dog fight. A large volume of serous fluids was identified on the wound immediately after atropine drops. A diagnosis of parotid salivary duct rupture secondary to trauma was made. On surgical exploration, the thickened proximal segment of the severed duct was identified and circumferentially double ligated with 3–0 silk. No evidence of swelling and normal appearance of the parotid salivary gland were identified 4 months postoperative recheck. No further problems were noted 10 months postoperatively phone-call. To the author’s knowledge, this is the first reported case of successful proximal parotid duct ligation of parotid salivary duct rupture secondary to non-iatrogenic trauma.

Surgical Excision of the Parotid Salivary Gland for Treatment of a Traumatic Mucocele in a Dog

A 3 yr old spayed female mixed-breed German shepherd dog was presented with a right facial swelling that developed after fighting with another dog. A parotid salivary mucocele was diagnosed via physical examination, fine-needle aspirate, and sialography of the parotid and mandibular salivary glands. Surgical excision of the right parotid salivary gland and duct was performed along with drainage of the mucocele. Neither intraoperative nor postoperative complications occurred, and follow-up examination 4 mo later revealed no evidence of recurrence. Case outcome was considered excellent. Sialography was useful for confirming the parotid gland as the source of the mucocele. Surgical excision of the parotid salivary gland is technically challenging, but an effective treatment option for traumatic mucoceles in the dog.

Salivary gland enlargement and sialorrhoea in dogs with spirocercosis: a retrospective and prospective study of 298 cases

This longitudinal cross-sectional clinical study investigated the incidence of sialorrhoea in dogs with spirocercosis and determined whether breed, body weight and the extent of the oesophageal involvement was associated with this presentation. A retrospective analysis was performed on the medical records of 233 dogs and information pertaining to 65 dogs was collected as part of a prospective study. All the animals were client-owned. Patients from the retrospective study underwent thoracic radiography or oesophageal endoscopy to diagnose and characterise the infection and were placed on therapy with a macrocyclic lactone, whereas the patients in the prospective study had both radiography and endoscopy routinely performed and biopsies of the oesophageal nodules collected where possible. Tru-cut biopsies of affected salivary glands were taken in 10 of 13 patients demonstrating clinical signs of sialorrhoea and salivary gland enlargement. The entire salivary gland was sectioned in an additional three dogs with spirocercosis and no sialorrhoea that were presented for post mortem examination. Sialorrhoea was present in 33/298 cases (11%). Fox terrier breeds were over-represented in the patients with sialorrhoea, comprising 36% of cases, whereas they only comprised 1.5% of the patients without sialorrhoea (p < 0.001, chi squared test) and 5% of the combined group. Dogs weighing 12 kg or less were significantly over-represented in the sialorrhoea group, 69% versus 19.5% (p < 0.001, chi square test). Age was not significantly different between the two groups (p < 0.08, Mann-Whitney test). The number of oesophageal nodules per case was significantly higher in the non-sialorrhoea cases (p = 0.048, Mann-Whitney test). The prevalence of distal oesophageal and lower oesophageal sphincter involvement, and neoplastic transformation of the nodules were not statistically different between the two groups. None of the fox terriers in either group showed neoplastic transformation of the parasitic nodules even though they were over-represented as a breed. Mandibular salivary glands were affected in 86% of cases showing sialorrhoea. Histopathology revealed acinar hyperplasia in all cases with concurrent necrosis detected in only two cases.Sialorrhoea and salivary gland enlargement has an incidence of 11% (33/298 cases) in canine spirocercosis. Small breeds (≤ 12 kg) and particularly fox terrier breeds are over-represented in the group demonstrating sialorrhoea and this appeared to be the only risk factor.The conclusion was that sialorrhoea secondary to canine spirocercosis occurs frequently and its presence should prompt further investigation for oesophageal and gastro-intestinal disease. Severely affected patients can be managed with phenobarbitone to control the dysphagia in addition to the routine macrocyclic lactones treatment.

Parotid Duct Sialolithiasis in a Dog

Computed tomography was used to evaluate a 7-year-old English bulldog with a history of facial swelling and to aid in the diagnosis of parotid duct sialolithiasis. Removal of the sialolith with repair of the duct was not possible because of ductal fibrosis. Histological evaluation revealed glandular atrophy and fibrosis with lymphoplasmacytic inflammation. The parotid duct was ulcerated and fibrotic, with a mixed inflammatory infiltrate. Surgical excision of the parotid duct and salivary gland was curative.

Parotid duct dilation in two dogs

Two cases of parotid duct dilation are described; the clinical signs on initial examination were a tubular swelling over the lateral aspect of the face with an associated intraoral submucosal distension. Surgical exploration confirmed that the distended structure was the dilated parotid duct and intraoral marsupialisation resulted in no recurrence postsurgery.

Idiopathic phenobarbital-responsive hypersialosis in the dog: an unusual form of limbic epilepsy?

Three unusual cases of salivary gland enlargement and hypersialosis in the dog that responded to anticonvulsant therapy are reported. Presenting complaints included weight loss, hypersalivation, retching and vomiting of several weeks' duration. Two dogs were presented with enlarged painful mandibular salivary glands. The third dog exhibited bizarre behaviour (including jaw chattering) and developed enlarged painful mandibular salivary glands during hospitalisation. Fine needle aspirate cytology and biopsies from the enlarged salivary glands revealed no significant pathological changes. In one dog, an electroencephalogram revealed changes consistent with epilepsy. Hypersialism and salivary gland enlargement resolved completely during phenobarbital administration in all cases. Two dogs were successfully weaned off treatment six months after diagnosis. The remaining dog relapsed after eight months, but normalised with the addition of oral potassium bromide. It is hypothesised that the syndrome idiopathic hypersialosis may in fact be an unusual form of limbic epilepsy.

Idiopathic salivary gland enlargement (sialadenosis) in dogs: a microscopic study

A histological, histochemical and morphometric study was performed on submandibular salivary glands from 13 dogs which had presented with a submandibular mass or swelling that proved to be a portion of non-inflammatory and non-neoplastic submandibular salivary gland. There were no consistent changes in lectin-binding histochemistry or immunohistochemical expression of various cell markers, and, in most cases, there was no measurable difference in acinar size in the affected gland. The possible explanation for the clinical salivary gland enlargement is therefore unclear.