A retrospective study of salivary gland diseases in 179 dogs (2010-2018)

The comparative morphology of the oral cavity glands in captive South African painted dogs (Lycaon pictus pictus) and captive fennec foxes (Vulpes zerda) (Carnivora: Canidae)

BACKGROUND

The African painted dog is classified as a relic canid lineage, inhabiting areas south of the Sahara. The fennec fox is the smallest member of the Canidae family, found in the Arabian Peninsula and northern Sahara.

METHODS

The gross anatomy and light microscopic examination of the oral cavity glands were studied in five adult captive South African painted dogs and five adult captive fennec foxes from the Wroclaw Zoological Garden, Poland. In this research, the zygomatic gland, monostomatic sublingual gland, polystomatic sublingual gland, mandibular gland, and parotid gland were examined for their topography, morphometry, histology, and histochemistry using hematoxylin and eosin, azan trichrome, mucicarmine, PAS, AB pH 1.0, AB pH 2.5, AB pH 2.5 PAS, and HID.

RESULTS

We found that the parotid glands were consistently the largest, followed by the mandibular and sublingual glands (both monostomatic and polystomatic). The zygomatic gland was the smallest in both South African painted dogs and fennec foxes. Interestingly, there were noticeable differences in the size, shape, and even composition of the secretory products between the two species. The zygomatic and polystomatic sublingual glands in the South African painted dog and the fennec fox were complex branched tubular. In the South African painted dog, the monostomatic gland was a branched tubular compound gland, while in the fennec fox, it was a branched tubuloalveolar compound gland. The mandibular gland in hunting dogs was a branched tubular compound gland, while in the fennec fox a branched tubuloalveolar compound gland. The parotid gland in the fennec fox was a branched acinar compound gland, whereas in the painted dog was a branched tubuloacinar.

CONCLUSIONS

The basic structure of their glands is similar to that of other terrestrial carnivores, indicating a shared evolutionary origin and function. However, differences in the composition of their secretory products can reflect adaptations to their specific diets. This research provides valuable insights for veterinary medicine and underscores the importance of further studies. By analyzing wild canid populations and including a broader range of species with diverse diets, we could gain a deeper understanding of how diet influences salivary gland morphology within the Canidae.

Severe Bilateral Sialadenitis of the Mandibular and Parotid Salivary Glands with Severe Panniculitis in a 2-Year-old Standard Poodle

A 2-year-old male neutered Standard Poodle weighing 17.9 kg was presented to their primary care veterinarian for enlarged bilateral submandibular swellings following an interdog altercation sustained in the previous weeks. Cytology performed following fine-needle aspirates of the regions of swelling was inconclusive, and the patient was treated empirically with Clavaseptin. Despite treatment, the submandibular swellings continued to enlarge, and right-sided intermittent epistaxis was reported. On biochemical profile, there was mild hypercalcemia and mild hyperglobulinemia. The computed tomography (CT) findings were indicative of severe multifocal sialadenitis with severe regional cellulitis and inflammatory lymphadenopathy. Histopathology and cytology results described mixed inflammation of the salivary gland. Methenamine silver staining and Fite's acid-fast staining were negative. Aerobic and anaerobic cultures were negative. Targeted, next-generation DNA sequencing detected no known fungi or bacterial pathogens. These findings were consistent with the diagnosis of severe bilateral mandibular sialadenitis, panniculitis, and lymphadenopathy. The patient was prescribed enrofloxacin, clindamycin, phenobarbital, and prednisolone for 1 month. One week after initiating treatment, the patient had a significant reduction in size of the salivary glands. CT imaging was helpful in the diagnosis of this patient and allowed the clinician to identify which submandibular anatomical structures were abnormal, guiding subsequent diagnostic decisions to provide medical management to resolve the condition.

Clinical findings, surgical treatment and outcome in dogs with parotid duct ectasia: 14 cases (2010-2023)

OBJECTIVES

To describe the clinical presentation, diagnostic findings, surgical treatment and outcome of dogs diagnosed with parotid duct ectasia.

MATERIALS AND METHODS

Medical records of dogs diagnosed with parotid duct ectasia between 2010 and 2023 at six small animal referral hospitals were retrospectively reviewed. Outcome was assessed by contacting the owners or referring veterinarians.

RESULTS

Fourteen dogs were included. Lateral facial swelling was the most common clinical presentation. CT revealed a tortuous cavitary tubular fluid-filled structure consistent with a dilated parotid duct in all dogs. Surgical treatment included marsupialisation of the parotid duct papilla, surgical exploration of the duct alone, parotid duct marsupialisation with surgical exploration of the duct, parotidectomy or en-bloc parotid duct resection. The aetiology of parotid duct ectasia was not established in 13 of 14 dogs. In one case, a foreign body was retrieved from the duct. No recurrence of clinical signs was noted during the follow-up period (range 21 to 2900 days).

CLINICAL SIGNIFICANCE

Parotid duct ectasia should be considered for dogs with a lateralised fluctuant non-painful tubular facial swelling. Surgical management was associated with a favourable prognosis without evidence of recurrence in all cases reported in the case series.

Computed tomographic characteristics of normal salivary glands in dogs

Background

Various salivary gland diseases diagnosed on computed tomography (CT) in dogs have been reported. However, no study described the size and CT attenuation value of normal salivary glands in dogs.

Aim

This retrospective analytical study aimed to evaluate the size and attenuation value of the mandibular and zygomatic salivary glands on CT in dogs without cervical or head lesions.

Methods

The maximum cross-sectional area (MCSA) was measured in 96 dogs and attenuation value on non-contrast and postcontrast images were measured in 90 dogs. Dogs were divided into three groups based on body weight: group 1, ≤ 5.0 kg; group 2, 5.1-10.0 kg; and group 3, 10.1-15.0 kg.

Results

There were significant differences in MCSA for both glands among the three groups. There was no difference in MCSA between the left and right sides in both salivary glands. The MCSA for both salivary glands positively correlated with body weight (p < 0.001). There was a significant difference in the MCSA of the zygomatic gland between males and females (p = 0.02), but there was no significant difference in the mandibular gland. There was a significant difference in the attenuation value between the mandibular and zygomatic glands in non-contrast studies (p < 0.001), but there was no significant difference in postcontrast studies.

Conclusion

This study established the reference for the size and attenuation value of the mandibular and zygomatic glands in dogs and provided background data for future CT evaluation of dogs with salivary gland diseases.

Canine salivary gland carcinoma treated with stereotactic body radiation therapy: a retrospective case series

Objective

The aim of this study was to describe the therapeutic outcomes of dogs with locally advanced salivary gland carcinomas (SGC) following stereotactic body radiation therapy (SBRT).

Methods

A single institution retrospective study was conducted of client-owned dogs with macroscopic SGC treated with SBRT. Patient signalment, clinical characteristics, and treatment parameters were recorded. Clinical benefit was determined based on follow-up physical examination and medical history. Progression-free interval (PFI), median survival time (MST), and disease-specific survival (DSS) were calculated using Kaplan-Meier analysis. Acute and late toxicity were recorded according to Veterinary Radiation Therapy Oncology Group (VRTOG) criteria.

Results

Six patients were included in the study. Tumor origins were mandibular (n = 3), parotid (n = 2), and zygomatic (n = 1) salivary glands. The SBRT prescription was 10 Gy × 3 daily or every other day. All patients (100%) experienced clinical benefit from treatment at a median time of 34 days (range 28-214). No local or regional nodal failure was reported following SBRT. Progressive pulmonary metastatic disease was documented in three dogs (50%). The median PFI was 260 days (range 43-1,014) and the MST was 397 days (range 185-1,014). Median DSS was 636 days (range 185-1,014). Four dogs (66.6%) died of confirmed or suspected metastatic SGC. The reported acute side effects included grade 2 mucositis (n = 1) and vision loss (n = 1). No late side effects were recorded.

Conclusion

This study suggests that SBRT may provide durable local control for invasive SGC in dogs. Further investigation in a larger cohort of patients is warranted. The incidence of reported acute and late toxicity was low.

Diagnostic Findings and Surgical Management of Three Dogs Affected by Osseous Metaplasia Secondary to a Salivary Mucocele

Saliva is an irritant of the subcutaneous tissue, thus causing the development of a non-epithelial reactive pseudocapsule. Metaplastic ossification of the pseudocapsule is a condition rarely described in the veterinary literature. The main causes of calcification are trauma, tumours, various chronic inflammatory conditions and fibrodysplasia ossificans progressiva. The aim of the present case series was to describe three dogs affected by a calcified salivary mucocele. The medical records of dogs affected by a cervical sialocele were retrospectively evaluated, and three cases met the inclusion criteria. All the dogs in this study were referred to the Veterinary Teaching Hospital (VTH) of the Department of Veterinary Sciences of the University of Turin (Turin, Italy) for a large solid mass in the intermandibular region. The diagnosis of a mucocele was confirmed clinically by centesis and by radiography or CT. Complete excision of both the pseudocyst and the ipsilateral mandibular/monostomatic sublingual salivary gland was performed in all cases. The histological report showed large areas of bone metaplasia within the pseudocapsule and chronic sialadenitis. Based on this limited case series, complete excision of the pseudocyst and a concurrent sialoadenectomy provided an effective treatment for this rare salivary mucocele disorder.

Intraoral approach for zygomatic sialoadenectomy in dogs: An anatomical study and three clinical cases

OBJECTIVE

To describe an intraoral approach (IOA) for zygomatic sialadenectomy in dogs and to compare this surgical approach to a modified lateral orbitotomy approach (LOA).

STUDY DESIGN

Cadaveric study and short case series.

SAMPLE POPULATION

Ten canine cadavers and three dogs with clinical disease.

METHODS

Bilateral zygomatic sialoadenectomies were performed in six mesocephalic, two brachycephalic and two dolichocephalic cadavers, randomly assigned to IOA on one side and LOA on the contralateral side. Duration of surgery, ease of surgical stage scores (rated on 5-point Likert scale) and completeness of gland removal were recorded. Additionally, IOA was performed in three dogs with zygomatic salivary gland (ZSG) disease.

RESULTS

Removal of the ZSG was complete in 8/10 and 10/10 dogs using the IOA and LOA, respectively. Surgery was faster with IOA (42.0 min; 33.5-49.6 min) than LOA (65.7 min; 54.9-76.4 min, p = .005). Ease of removal did not differ between approaches (p = .091). Diseased ZSGs were successfully removed in three dogs without intra- or short-term postoperative complications.

CONCLUSIONS

The intraoral approach described here was technically equally challenging but faster than the LOA. Its clinical use led to an uneventful surgery with excellent short-term outcome in three dogs.

CLINICAL RELEVANCE

The IOA provides an alternative approach for zygomatic sialoadenectomy in dogs with ZSG disease.

High-grade mucoepidermoid carcinoma of the salivary gland in a bull

Salivary gland neoplasia is uncommon in veterinary species and has rarely been reported in cattle. Adenocarcinoma, squamous cell carcinoma, and pleomorphic carcinoma have been described in the parotid gland of dairy cows. Here we describe a case of high-grade mucoepidermoid carcinoma in a bull. The bull had a chronic history of caudal mandibular soft tissue swelling. Postmortem examination revealed a 30 × 30-cm mass with a caseonecrotic center, hemorrhage and necrosis of the ipsilateral cervical musculature, osteolysis of the right paracondylar process of the skull and right horn base, pulmonary nodules, and enlarged tracheobronchial lymph nodes. Histology of the mass, lungs, and lymph nodes revealed an invasive neoplasm composed of epithelial cells arranged in nests and ductular structures supported by a spindle cell stroma, with frequent central necrosis. Immunohistochemistry revealed that epithelial cells were diffusely positive for pancytokeratin and p63 with multifocal vimentin positivity; stromal cells were diffusely positive for vimentin and α-SMA. A salivary gland mucoepidermoid carcinoma was diagnosed based on these findings. Although rare, salivary gland neoplasia should be considered a differential diagnosis for mandibular masses in cattle.

Lesions of the oral cavity of dogs: 720 cases

ABSTRACT: Seven hundred twenty cases of oral cavity lesions in dogs were diagnosed from 2015 to 2020 in Distrito Federal, Brazil. Four hundred thirty-two (60%) lesions were neoplastic, and 288 (40%) were non-neoplastic. Of the neoplasms, 229 (53%) were considered malignant and 203 (47%) benign, affecting mainly males, of 43 different breeds, with an average age of 9.4 years, mainly the gum and lip. Melanoma was the most (96/432, 22.2%) commonly diagnosed neoplasm, followed by peripheral odontogenic fibroma (68/432, 15.7%), papilloma (63/432, 14.5%) and squamous cell carcinoma (SCC) (56/432, 12.9%). Non-neoplastic lesions also affected males predominantly, from 41 different breeds, with an average age of 8.9 years, mainly in the gums, lip, and tongue. These lesions were diagnosed as inflammatory (230/288, 79.8%), hyperplastic (47/288, 16.3%) and other lesions (11/288, 3.8%).

Clinical outcomes of thyroid tumours with concurrent epithelial and mesenchymal components in 14 dogs (2006-2020)

Background

While rare, multiple individual case reports have described mixed thyroid tumours in dogs containing both epithelial and mesenchymal neoplastic components.

Objectives

In this retrospective case series, we describe the clinical presentation, treatment and outcome of 14 dogs of canine thyroid tumours with concurrent mesenchymal and epithelial neoplastic populations.

Methods

Fourteen cases were retrospectively abstracted from nine institutions. Histopathologic samples and reports were collected from 10/14 dogs and reviewed by a single board‐certified anatomic pathologist.

Results

All 14 dogs had curative‐intent surgery to remove the thyroid neoplasm. The most common surgery performed was a unilateral thyroidectomy (10/14 dogs). Postoperatively, systemic therapy was administered in eight dogs. Six dogs developed local recurrence with a median time to loco‐regional recurrence of 53 days. Ten dogs developed metastatic disease with the most common metastatic site being the lungs (6/10 dogs), with a median time to metastasis of 93 days. Ten dogs were euthanised due to locoregional or distant progression of their mixed thyroid neoplasm. The overall median survival time was 156 days (95%CI: 49–244). The median survival time for dogs treated with adjuvant therapy was 189 days (95%CI: 24–244), whereas dogs without adjuvant therapy had a median survival time of 156 days (95%CI: 35‐upper limit could not be calculated; p = 0.62).

Conclusion

The thyroid tumours with both mesenchymal and epithelial components in this small sample set were associated with a poor prognosis after surgical excision with or without adjunctive therapy.

Zygomatic sialocele secondary to infarction treated with sialoadenectomy in a dog

Zygomatic salivary gland disease is not commonly reported in dogs and there is a paucity of literature reporting salivary gland disease secondary to infarction in dogs. A 9-year-old German wirehaired pointer presented with left eye exophthalmos, 3rd eyelid elevation, negative retropulsion, and pain upon opening of the mouth. Computed tomography revealed a mass extending from the left zygomatic salivary gland, consistent with a sialocele. A left-sided zygomatic sialoadenectomy was performed successfully. Histopathologic diagnosis concluded zygomatic salivary gland infarction. The dog had no signs of recurrence 20 mo after surgery. Key clinical message: To the authors' knowledge, this is the first case report with long-term outcome of a zygomatic sialocele secondary to salivary gland infarction in a dog treated by zygomatic sialoadenectomy via zygomatic osteotomy.