Concurrent sialocoele and necrotising sialadenitis in a dog

Canine bilateral zygomatic sialadenitis: 20 cases (2000-2019)

OBJECTIVES

To describe clinical findings, cross-sectional imaging features, management and outcome of dogs with bilateral zygomatic sialadenitis.

MATERIALS AND METHODS

Clinical databases of three referral institutions were searched for dogs diagnosed with bilateral zygomatic sialadenitis who underwent magnetic resonance imaging or computed tomography of the head. Signalment, history, clinical, laboratory and imaging findings were reviewed.

RESULTS

Twenty dogs with a mean age (±SD) of 7.1 (±2.7) years were included; Labradors were overrepresented (10/20). Common clinical signs included pain on opening the mouth (18/20), conjunctival hyperaemia (16/20), exophthalmos (15/20), periorbital pain (15/20), third eyelid protrusion (11/20) and resistance to retropulsion of the globes (11/20). Fifteen of twenty dogs had at least one concurrent systemic disease: skin allergy (5/15), hypertension (3/15), gastrointestinal (3/15), kidney (3/15), neurological (3/15) and periodontal disease (2/15), pancreatitis (2/15) and neoplasia (2/15). Neutrophilia (9/18) and leukocytosis (7/18) were the most common haematological abnormalities. When performed (11/20), aspiration cytology revealed predominantly degenerate neutrophils (9/11) and only 2/9 culture samples yielded bacterial growth. The zygomatic glands were predominantly hyperintense on both T1 and T2-weighted images (22/24) and symmetrically enlarged (20/24) with marked and heterogeneous contrast enhancement (18/24). In the computed tomography studies, the zygomatic glands were all hyperattenuating and contrast enhancing. Treatment included systemic antimicrobial (18/20), anti-inflammatory (14/20) and supportive treatment (16/20). Clinical signs improved in 16/20 dogs; however, 4/20 dogs were euthanised due to severe systemic disease.

CLINICAL SIGNIFICANCE

Bilateral zygomatic sialadenitis is frequently associated with systemic disease in dogs. Clinical signs generally improve with systemic antimicrobial, anti-inflammatory and supportive treatment.

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.

Multi-institutional study of long-term outcomes of a ventral versus lateral approach for mandibular and sublingual sialoadenectomy in dogs with a unilateral sialocele: 46 cases (1999–2019)

OBJECTIVE

To compare the long-term outcomes of a ventral versus lateral surgical approach for mandibular and sublingual sialoadenectomy in dogs with a unilateral sialocele.

ANIMALS

46 client-owned dogs.

PROCEDURES

Medical records of dogs that underwent unilateral sialoadenectomy between 1999 and 2019 were retrospectively reviewed, and information was collected regarding signalment, clinical signs, historical treatment, swelling location, diagnostic imaging findings, sialoadenectomy approach, adjunctive treatments, intraoperative complications, hospitalization time, postoperative complications, recurrence, and contralateral sialocele development.

RESULTS

There were no significant differences in incidences of intraoperative complications, recurrence, or postoperative complications between dogs in which a lateral versus ventral approach was used. Clinically important intraoperative complications included iatrogenic tears in the oral mucosa, ligature slippage from the duct end, hemorrhage, and possible lingual nerve transection. Surgical experience was associated with the likelihood that intraoperative complications would develop. Suspected recurrence was reported in 2 of 26 (8%) dogs that underwent a lateral approach and 2 of 12 (17%) dogs that underwent a ventral approach. Hospitalization time was significantly shorter with the lateral approach than with the ventral approach. Postoperative complications had a short-term onset and occurred in 4 of 25 (16%) dogs that underwent a lateral approach and 3 of 12 (25%) dogs that underwent a ventral approach. Age and presence of a pharyngeal sialocele were associated with development of postoperative complications.

CLINICAL RELEVANCE

Long-term outcomes for ventral and lateral approaches to sialoadenectomy were favorable and appeared to be comparable. Further prospective study into potential associations of sialoadenectomy approach, age, and pharyngeal sialoceles on outcome is needed.

An Atypical Presentation of a Zygomatic Sialocele in a dog

A sialocele is an accumulation of salivary fluid due to leakage into the interstitial space surrounding the affected salivary gland and/or its corresponding duct. Reported causes of salivary leakage include trauma, foreign bodies, sialoliths, and neoplasia, but in many cases the etiology is not identified. Clinical signs of sialoceles associated with the zygomatic salivary gland or corresponding duct usually include exophthalmos due to periorbital salivary accumulation, whereas sialoceles associated with the mandibular or sublingual glands or ducts usually manifest as cervical, pharyngeal and/or sublingual salivary accumulation. This case report describes an atypical cervical presentation of a zygomatic sialocele in a dog that resolved after zygomatic sialoadenectomy.

Clinical and CT sialography findings in 22 dogs with surgically confirmed sialoceles

Sialoceles are an uncommon canine salivary gland disease, and complete surgical resection is important for a positive outcome. Radiographic sialography has been described as a diagnostic test for presurgical planning; however, superimposition artifacts may limit the diagnosis and detection of all affected glands. Computed tomographic (CT) sialography is a promising technique for delineating the salivary gland apparatus. The aims of this retrospective, observational study were to describe clinical and CT sialographic findings in a group of dogs with confirmed sialoceles, to determine the sensitivity of CT sialography for detecting affected salivary glands using surgery as the reference standard and to determine interobserver agreement for CT sialographic assessments. Dogs were included if they underwent a CT sialography study followed by surgical resection of the diseased gland(s) and histopathological analysis. Computed tomography sialography studies of dogs with surgically confirmed sialoceles (n = 22) were reviewed by a European College of Veterinary Diagnostic Imaging (ECVDI)-certified radiologist and an ECVDI resident. Interobserver agreement was calculated using Cohen's kappa statistics. CT sialography results were compared to surgical findings to determine sensitivity. Contrast leakage was detected in 12 of 22 dogs (54.5%), with intrasialocele leakage being most frequently observed (7/12, 58.3%). There was substantial agreement (κ = 0.70) between reviewers identifying diseased glands, substantial agreement (κ = 0.62) on the diagnostic quality, and no to slight agreement (к = 0.13) in the detection of contrast leakage. The overall sensitivity of CT sialography to detect surgically confirmed diseased glands was 66.7% (95% confidence interval: 48.8-80.8). In conclusion, these findings support the use of CT sialography as an adjunct diagnostic test for treatment planning in dogs with sialoceles.

Intracanalicular injection of N-acetylcysteine as adjunctive treatment for sialoceles in dogs: 25 cases (2000-2017)

OBJECTIVE

To describe intracanalicular injection of 10% N-acetylcysteine (IINAC) as adjunctive treatment for sialoceles in dogs.

ANIMALS

25 client-owned dogs.

PROCEDURES

Hard copy medical records at 2 veterinary ophthalmology practices were searched to identify dogs that underwent IINAC for treatment of sialoceles from January 2000 to December 2017. Signalment, affected salivary gland, clinical signs, duration of signs, other treatments administered, diagnostic tests performed, anesthetic approach, N-acetylcysteine volume administered, complications, follow-up time, and recurrence of sialoceles were recorded. Descriptive statistics were reported.

RESULTS

Boxers and mixed-breed dogs were most commonly represented. Subjectively decreased globe retropulsion and conjunctival or periorbital swelling (23/25 [92%] dogs each) were the most common clinical signs, with no vision deficits in any patient. The zygomatic gland was mainly affected (23/25 [92%] dogs), followed by parotid and mandibular glands (1 [4%] dog each). The condition was unilateral in 22 (88%) dogs. Ultrasonography (19/25 [76%] dogs), MRI (14 [56%]), fine-needle aspiration (20 [80%]), and biopsy (4 [16%]) were performed; however, the condition was deemed idiopathic in 22 (88%) dogs. Most IINACs were performed with local anesthesia (median volume, 5 mL/gland; range, 1.5 to 9 mL). No complications were identified. Other treatments included antimicrobials and anti-inflammatories. Mean follow-up time was 18.8 months. All recurrences (5/23 [22%] dogs) were controlled with medical management.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested noninvasive IINAC may be a useful adjunctive treatment for sialoceles in dogs. The procedure was easily and safely performed with local anesthesia (or general anesthesia with concurrent diagnostic imaging) in these dogs.

Comparison of three surgical approaches for zygomatic sialoadenectomy in canine cadavers

Objective

To compare three surgical approaches for excision of the zygomatic gland in dogs.

Study design

Cadaveric study.

Animals

Cadavers of mesocephalic dogs (n = 20).

Methods

Each skull was assigned to a lateral approach with zygomatic arch ostectomy on the left (n = 20) and one approach without ostectomy on the right, ventral (n = 10) or dorsal (n = 10) to the zygomatic arch. Approaches were evaluated for surgical exposure (rated on a scale of 1‐5 with one optimal exposure), tissue trauma, and completeness of gland removal. Glands from each side were weighed to compare as internal control.

Results

The ostectomy‐based approach offered excellent surgical view and good exposure of the zygomatic gland but caused more tissue trauma. The dorsal nonostectomy approach did not allow complete zygomatic gland extraction in nine of the 10 dogs, whereas the ventral nonostectomy approach enabled complete extraction in all 10 dogs.

Conclusion

The ventral zygomatic approach allowed complete removal of the zygomatic gland, with good surgical overview, while reducing tissue trauma and preserving the zygomatic arch.

Clinical significance

The ventral nonostectomy approach should be considered as an alternative to excise the zygomatic gland in dogs.

A Novel Technique for Partial V-shaped Zygomatic Arch Ostectomy for Excision of Zygomatic Salivary Glands in Dogs

The present study described a novel technique for a partial V-shaped ostectomy of the zygomatic arch (ZA) for surgical excision of the zygomatic salivary glands (ZSG) in dogs and addressed advantages and disadvantages related to this procedure. The study was conducted on 6 clinically healthy mongrel dogs. A 3-4 cm curvilinear transcutaneous incision was performed parallel to the dorsal margin of the ZA. An additional 2 cm vertical incision was performed perpendicular to the former one forming a T-shaped incision over the ZA. The skin, subcutaneous tissue, and periosteum over the ZA were dissected and reflected laterally. At 0.5 cm from the orbital ligament, a V-shaped segment from the ZA was resected using an electrical saw. The base of the V-shaped segment was 1.5 cm wide and its apex was 0.5 cm from the ventral margin of the ZA. A combination of sharp and blunt dissection was used to dissect and excise the ZSG from the surrounding tissues. The periosteal flaps were coaptated in a simple continuous pattern. The subcutaneous tissue and skin were closed as usual. The new approach was a feasible technique for the excision of the ZSGs without considerable postoperative complications in dogs. The novel V-shaped partial ostectomy of the ZA technique is reliable, satisfactory, and relatively less invasive for surgical excision of ZSGs in dogs. Further work should be conducted on clinical cases.

Sjögren's-like syndrome in a dog

A neutered male Golden Retriever was referred with a 2-week history of dry mouth. Multiple and bilateral enlargement of the lacrimal and salivary glands showing heterogeneous internal enhancement was identified on contrast-enhanced computed tomography (CT). Ultrasonographic examination detected multifocal hypoechoic areas within the swollen submandibular salivary glands, which were histopathologically diagnosed as lymphoplasmacytic sialoadenitis. As both imaging and histopathological findings were in accordance with those in human Sjögren's syndrome, a provisional diagnosis of Sjögren's-like syndrome was made. Immunosuppressive drugs promptly improved clinical signs concurrently with the abnormal sonographic findings, indicating the feasibility of ultrasonography in monitoring therapeutic outcomes. Herein, we discuss a proposed criteria set for diagnosis of Sjögren's-like syndrome in veterinary medicine.

Exophthalmos associated to orbital zygomatic mucocele and complex maxillary malformation in a puppy

A case of exophthalmos due to zygomatic mucocele in a puppy with ipsilateral segmental maxillary atrophy is reported. A 7-month-old, mixed breed, male dog suffered the sudden-onset of unilateral painful exophthalmos and a gradual swelling of the right temporal region. A compressing, right retrobulbar mass was observed by ultrasound. Computed tomography revealed a large multiloculated cyst-like lesion of the right zygomatic gland projecting into the orbital space, thus displacing the eyeball. The ipsilateral molar part of the maxillary bone was underdeveloped, besides showing crowded, abnormal, multiple, unerupted maxillary molar teeth in the caudal maxillary region. Modified lateral orbitotomy and a selective caudal maxillary bone access were performed. The cyst-like lesion was removed and the zygomatic gland and the wall was collected for histology, which confirmed the mucocele. Clinical and imaging examinations six months after surgery showed neither recurrence of the mucocele nor ocular abnormalities. A possible common pathogenic mechanism involving these two conditions could be hypothesized.

Clinical, computed tomographic, magnetic resonance imaging, and histologic findings associated with myxomatous neoplasia of the temporomandibular joint in two dogs

CASE DESCRIPTION A 15-year-old neutered female mixed-breed dog (dog 1) and an 11-year-old neutered female Labrador Retriever (dog 2) were examined because of unilateral exophthalmus, third eyelid protrusion, and periorbital swelling that failed to respond to antimicrobial treatment. CLINICAL FINDINGS Both dogs underwent ultrasonographic, CT, and MRI examination of the head. In both dogs, advanced imaging revealed a poorly defined, peripherally contrast-enhancing, mucous-filled cystic mass that radiated from the temporomandibular joint and infiltrated the periorbital tissues and retrobulbar space. Both dogs underwent surgical biopsy of the periorbital mass. A viscous, straw-colored fluid was aspirated from the retrobulbar region in both dogs. The initial histologic diagnosis for dog 1 was zygomatic sialadenitis and sialocele. However, the clinical signs recurred, and histologic examination of specimens obtained during a second surgical biopsy resulted in a diagnosis of myxoma. The histologic diagnosis was myxosarcoma for dog 2. TREATMENT AND OUTCOME In both dogs, clinical signs recurred within 2 weeks after surgery and persisted for the duration of their lives. Dog 1 received no further treatment after the second surgery and was euthanized 34 months after initial examination because of multicentric lymphoma. Dog 2 was treated with various chemotherapy agents and was euthanized 11 months after initial examination because of a dramatic increase in periocular swelling and respiratory stertor. CLINICAL RELEVANCE Temporomandibular myxomatous neoplasia can be confused with zygomatic sialocele on the basis of clinical signs but has characteristic MRI features. Representative biopsy specimens should be obtained from areas close to the temporomandibular joint to avoid misdiagnosis.

[Magnetic resonance imaging anatomy of the feline salivary glands]

OBJECTIVE

The aim of the study was to define anatomical characteristics of feline salivary glands using magnetic resonance imaging (MRI) and to describe landmarks for their reliable identification.

MATERIAL AND METHODS

Heads of 37 adult cats without signs of diseased salivary glands on clinical examination or history were examined. In cats included in the prospective part of the study, the MRI study was completed within one hour after euthanasia (n = 16). In the retrospective part, previously performed MRI studies were evaluated (n = 21). The prospective part of the study included the following standardized sequences: T2-weighted (T2W) turbo spin echo (TSE), T2W fat-suppressed TSE and proton density weighted (PDW) TSE images in a transverse plane as well as T1-weighted (T1W) fast field echo (FFE) in the transverse, sagittal and dorsal planes. In the retrospective part, T2W TSE and T1W TSE transverse images pre- and post-contrast were analyzed. Initially, identification and delineation of the salivary glands from surrounding tissue was assessed. Anatomical structures of the head were then identified and defined as landmarks. The dimensions of the glands were measured on T2W TSE images and the signal intensity in relation to that of fat and muscle was described using all sequences.

RESULTS

In total, 95.9% of the parotid glands and 100% of the mandibular glands could be visualized on T1W TSE and FFE images and on T2W TSE images. Additionally, 93.3% of the zygomatic glands were identified on T2W TSE sequences and 82.5% on T1W TSE and FFE images. The ventral buccal glands could be demarcated in some sequences (T2W TSE: 51.4%, T1W TSE and FFE: 18.9%). Anatomical landmarks facilitated gland identification. Comparing the size of the salivary glands of both groups revealed differences of up to 2 mm.

CONCLUSION

Both the large salivary glands (Glandula [Gl.]. parotis and Gl. mandibularis) and the small salivary glands (Gl. zygomatica and Gl. buccalis ventralis) of the cat can be reliably identified on MRI images.

Computed tomography and magnetic resonance diagnosis of variations in the anatomical location of the major salivary glands in 1680 dogs and 187 cats

During assessment of routine clinical magnetic resonance imaging (MRI) of the heads of dogs, variations in the location of mandibular and zygomatic salivary glands (SGs) were observed incidentally. The aims of this retrospective study were to describe anatomical variations of the major SGs found on MRI and computed tomography (CT) studies of the head in dogs and cats and to investigate possible clinical relevancy. No anatomical variation of the SGs was seen in cats, but in dogs, although variation of the parotid SG was not identified, that of the mandibular SG was found in 33/1680 animals (2%), either unilaterally (6/33 right-sided, 13/33 left-sided) or bilaterally (14/33). The Border terrier breed (19/33, 58%) was over-represented. Each atypically located mandibular SG was positioned medial to the digastric muscle and rostral to the retropharyngeal lymph node. The sublingual glands were difficult to delineate from the mandibular glands. Anatomical variation of one zygomatic gland (3/4 left-sided) was identified in four small-breed dogs (0.2%). Each atypically located zygomatic gland was tilted at the ventrorostral aspect of the masseter muscle underneath the skin surface. MRI and CT characteristics were not different between typically and atypically located SGs. None of the dogs had clinical signs related with SG disease. It was concluded that, with suspected breed predispositions, incidental unilateral or bilateral anatomical variations of mandibular and zygomatic SGs can be encountered in dogs and an awareness of these possible variations may be important in pre-surgical planning.

Phenobarbital-responsive sialadenosis in dogs: case series

Phenobarbital-responsive sialadenosis (PRS) is a rare idiopathic disease in dogs. Vomiting, retching, and gulping with bilateral enlargement of the submandibular salivary glands are the more frequent clinical signs. A thorough diagnostic examination must be performed to rule out the most important systemic etiologies involved with chronic vomiting, as there is no specific test to diagnose PRS. Diagnosis is confirmed clinically by a rapid and dramatic improvement of clinical signs after instauration of phenobarbital treatment. The aim of this article is to describe the clinical presentation, diagnostic findings, and outcome of a case series of 4 dogs with presumptive PRS.

Mucocele in a spectacled owl (Pusilatrix perspicillata)

A 6-year-old breeding female spectacled owl (Pusilatrix perspicillata) was presented for a soft, fluid-filled, spherical mass under the neck that had been increasing in size over the previous 3 days. Results of a fine-needle aspirate of the mass showed clear, pale-yellow fluid with a total protein of 12.6 g/L. Cytologic examination revealed erythrocytes, moderate numbers of heterophils, and numerous foamy mononuclear cells against a mucoid background. Macroscopically, the mass appeared to be attached firmly to the esophagus. The mass was excised surgically and submitted for histopathologic examination. The lesion comprised a circumscribed, fibrous-encapsulated multilocular cyst, lined by plump, goblet-type, cuboidal epithelial cells lying in abundant mucinous matrix. Findings were consistent with a mucocele of the esophageal mucosal gland. Excision was considered curative based on follow-up 6 months after initial presentation. To our knowledge, this is the first report of this condition in Strigiformes and indicates that mucocele should be included in the differential diagnosis of cervical masses in birds.

Zygomatic salivary gland diseases in the dog: three cases diagnosed by MRI

This article describes three original cases of zygomatic gland disease in the dog diagnosed by low-field MRI and treated by a modified lateral orbitotomy with zygomatic osteotomy. Presenting complaints included exophthalmia, protrusion of the third eyelid, and periorbital swelling without any history of trauma. Low-field MRI allowed for adequate diagnosis of zygomatic gland disease in all cases and provided detailed information about both the specific tissue characteristics of each lesion and extension into surrounding structures. MRI findings were also helpful for surgical planning and dictated the choice of a modified lateral orbitotomy without removal of the orbital ligament. Histopathologic diagnosis for each of the three dogs was a mucocele, a malignant mixed salivary tumor, and sialadenitis.

Clinical and ultrasonographic characteristics of salivary mucoceles in 13 dogs

Salivary mucocele is one of the causes of submandibular swelling in dogs and is due to a collection of mucoid saliva that has leaked from a damaged salivary gland. The purpose of this case series report was to describe the clinical and ultrasonographic characteristics of confirmed salivary mucoceles in 13 dogs admitted to the Faculty of Veterinary Medicine at Cairo University. The final diagnosis of salivary mucocele was based on aspirate cytology for all dogs and additional surgical excision for seven dogs. For dogs admitted from 2 weeks to 1 month from the onset of clinical signs, the cervical mucocele appeared as a round echogenic structure with a large volume of central anechoic content. The wall was a clearly identified hyperechoic structure surrounding the gland. For dogs admitted between 1 to 2 months from the onset of clinical signs, the volume of anechoic material appeared less than that seen in the acute cases. The overall appearance of the salivary mucocele was heterogenous. For dogs admitted after 2 months from the onset of clinical signs, the salivary mucocele appeared grainy or mottled, with a heterogenous appearance and a further decrease in anechoic content. For one dog that presented after 3 months from the onset of clinical signs, the salivary mucocele was hard on palpation and appeared hyperechoic with distal acoustic shadowing. Findings from this study indicated that ultrasonographic characteristics of salivary mucoceles in dogs vary depending on the chronological stage of the disease.

Clinical and diagnostic imaging findings in dogs with zygomatic sialadenitis: 11 cases (1990-2009)

OBJECTIVE

To describe clinical and diagnostic imaging features of zygomatic sialadenitis in dogs.

DESIGN

Retrospective case series.

ANIMALS

11 dogs with zygomatic sialadenitis and 20 control dogs without evidence of retrobulbar disease.

PROCEDURES

Medical records were searched for dogs with zygomatic sialadenitis that underwent some combination of magnetic resonance imaging (MRI), computed tomography (CT), and ultrasonography. Signalment, clinical signs, results of clinicopathologic tests, cytologic and histologic diagnosis, treatment, qualitative disease features, and disease course were recorded. Images obtained via MRI or CT were analyzed for pre- and postcontrast signal intensity or density, respectively; zygomatic salivary gland area was determined. Results were compared with those of control dogs that underwent the same imaging procedures (n = 10/method). Ultrasonographic images of affected dogs were assessed qualitatively.

RESULTS

Most (9/11) affected dogs were medium- or large-breed males (mean age, 8 years) with unilateral disease. Affected dogs had clinical signs of retrobulbar disease and cytologic or histologic evidence of zygomatic sialadenitis. Sialoceles were detected in 7 affected glands. Compared with values for control dogs, MRI findings in affected dogs (n = 7) included gland enlargement, T1-weighted hypointensity, T2-weighted hyperintensity, and increased contrast enhancement; CT features in affected dogs (2) included gland enlargement and hypodensity on unenhanced images. Retrobulbar masses were identified via ultrasonography in 9 of 10 orbits examined, and zygomatic salivary gland origin was detected in 4.

CONCLUSIONS AND CLINICAL RELEVANCE

Visualization of anatomic structures for diagnosis of zygomatic sialadenitis and evaluation of adjacent structures was excellent via MRI and CT Ultrasonography was less definitive but useful for sample collection.

Zygomatic salivary mucocoele as a postoperative complication following caudal hemimaxillectomy in a dog

Zygomatic mucocoele is reported as a postoperative complication occurring secondary to a caudal hemimaxillectomy in a two-year-old Labrador retriever. The dog was presented with a history of a rapidly growing oral mass, identified as a soft tissue sarcoma. A caudal hemimaxillectomy via an intraoral approach was performed as treatment for local control of the oral mass. Fifteen days postoperatively, periorbital swelling and exophthalmos developed on the ipsilateral side. The degree of swelling progressed and was identified by computed tomography, ultrasound and cytology as a salivary mucocoele. Zygomatic sialoadenectomy was performed via a modified lateral approach with zygomatic osteotomy. A small amount of discharge persisted from the surgical site but gradually resolved. Recurrence of the periorbital swelling and exophthalmos was noted 25 days later and further surgery was performed to excise residual salivary tissue. Adjuvant radiotherapy was performed, however local recurrence of the oral mass was identified 5 months postoperatively and the patient subsequently euthanased. Salivary mucocoele has been cited as a possible postoperative complication following maxillectomy and mandibulectomy procedures; however to the authors' knowledge, only one previous case report exists in the literature. The current case documents a zygomatic salivary mucocoele occurring subsequent to caudal hemimaxillectomy.