Phenobarbital-responsive ptyalism, dysphagia, and apparent esophageal spasm in a German shepherd puppy

A 10-week-old, male German shepherd dog was presented with a primary complaint of episodic ptyalism, dysphagia, vomiting, and mandibular salivary gland enlargement. An esophagram with fluoroscopy showed normal pharyngeal and esophageal function; however, upper gastrointestinal endoscopy and cervical ultrasonography revealed a focal circumferential thickening of the midcervical esophageal muscular wall, consistent with esophageal spasm. The puppy responded dramatically and completely to phenobarbital treatment. An unusual syndrome of phenobarbital-responsive hypersialosis was consistent with this dog's clinical presentation and the finding of apparent esophageal spasm. The pathogenesis of this syndrome is unclear, but it may represent a form of limbic epilepsy or peripheral autonomic dysfunction.     

Esophageal obstruction by antibiotic boluses in a thoroughbred filly: A case report

A case of equine midcervical esophageal obstruction by medicinal boluses is described. A discussion of the physical and endoscopic examination is included. Attempts at medical and manipulative therapy including massage, intraesophageal probing and endoscopically assisted efforts to snare the obstruction were nonrewarding. A standing midcervical esophagotomy was performed to facilitate the removal of the entrapped boluses. A positive contrast esophagram obtained five days after surgery indicated an absence of leakage of contrast media from the lumen of the esophagus. The filly was returned to athletic competition at seven days following surgery. No evidence of dysphagia or esophageal obstruction was reported six months following surgery. In this particular case, a standing midcervical esophagotomy afforded a successful alternative when manipulative and medical therapy proved inadequate.     

Abnormal changes in both mandibular salivary glands in a dog: Non-mineral radiopaque sialoliths

A 10-year-old Maltese dog was presented with a firm mass on the left side of his neck. Physical examination confirmed a firm mass in the left and a submandibular swelling in the right cervical region. Sialolithiasis and associated sialocele in both mandibular salivary glands were suspected and bilateral sialoadenectomy was performed. The stones were identified as non-mineral sialoliths.     

Malignant fibrous histiocytoma (giant cell type) associated with a malignant mixed tumor in the salivary gland of a dog

A 12-year-old male Boxer dog presented with a 5 x 5 x 7-cm partially encapsulated mass in the right mandibular salivary gland. Histologically, the mass was composed of neoplastic epithelial and mesenchymal cells. The mesenchymal component consisted of two cell populations arranged in different patterns: coalescing nodules of neoplastic mononuclear cells with rare osteoid and numerous osteoclastlike giant cells; and sheets of neoplastic spindle cells intermingled with neoplastic epithelial cells and containing osteoid and well-formed bone trabeculae lined by osteoblasts and few osteoclastlike giant cells. On the basis of these histological features, two malignant salivary tumors were diagnosed: a malignant fibrous histiocytoma (giant cell type) and a malignant mixed tumor. Immunohistochemical studies demonstrated keratin 5 and 8 expression by the neoplastic epithelial cells, indicating a probable salivary ductal origin, and vimentin expression by all mesenchymal elements, suggesting a fibroblastic line of differentiation.     

Standing transcutaneous surgical excision of a sialolith in an 11-year-old Thoroughbred mare

An 11-year-old Thoroughbred mare was diagnosed with sialolithiasis of the right parotid salivary duct. A firm nonpainful subcutaneous mass was palpable in the right maxillary region adjacent to premolar 4 (tooth 108). Radiographic and ultrasonographic examinations identified a discrete mineralised ovoid mass that was hyperechoic and produced an acoustic shadow. Surgical excision of the mass was performed under standing sedation using a transcutaneous approach and the excised sialolith submitted for histopathological and mineral composition analyses. Histological examination found no evidence of a nidus at the sialolith's core. Mineral analysis of the sialolith revealed its composition to be 40% calcium phosphate (apatite) and 60% calcium carbonate. The mare recovered with no post-operative complications and was clinically unremarkable 2 years later.     

Infiltrative angiolipoma of the parotid salivary gland in a dog

Solitary benign angiolipoma and infiltrative angiolipoma are rare tumours in dogs. Angiolipomata can be distinguished histologically from lipomata by the large number of tightly packed blood vessels seen between the adipocytes with multiple fibrin thrombi occupying some of the vessels' lumens. The dog presented with a solitary slow-growing mass in the cervical region. Histopathology revealed multifocal to coalescing single or clusters of blood-filled vessels lined by flattened endothelial cells with narrow, elongated, basophilic nuclei. These regions were embedded in adipose tissue with multifocal areas of intervascular remnants of differentiated serous salivary glandular tissue with multifocal small ducts. Fibrin thrombi occupied a few of the vessel lumens. A histological diagnosis of infiltrative angiolipoma was made. On computed tomography, the mass was bilobed with a suspected primary component involving the right parotid gland which was grossly enlarged. The mass had a slightly hypoattenuating mottled to lobulated appearance with a few hyperattenuating mineralised specks throughout. Hounsfield units of the mass ranged between 40 and 45, which was less than the 60-65 of the contralateral salivary glands and cranial musculature. Post contrast images showed no contrast enhancement of 90% of the mass with only a band of peripheral contrast uptake of the affected lateral lobe.     

Dynamic tracheal collapse as a cause of exercise intolerance in a thoroughbred

A 2-year-old Thoroughbred filly was admitted to the hospital for evaluation of exercise intolerance. Resting videoendoscopic evaluation (i.e., while the horse was standing) of the nasopharynx and trachea revealed right arytenoid paresis and a tracheal defect that was 100 cm distal to the external nares. Surgery, consisting of a right prosthetic laryngoplasty, was performed. However, postoperative videoendoscopic evaluation revealed minimal abduction of the affected arytenoid cartilage. Dynamic videoendoscopic evaluation (i.e., while the horse was exercising) revealed the right arytenoid to be fixed in a submaximal position with no evidence of collapse into the airway. When the endoscope was positioned in the midcervical tracheal region, marked tracheal collapse was identified during exercise. Tracheal collapse can critically limit athletic function. Treatment of tracheal collapse depends on causative factors, the length of the trachea involved, and accessibility of the affected tracheal segment. The use of dynamic tracheal videoendoscopy should be considered in athletic horses with exercise intolerance in which the cause cannot be determined from resting or dynamic videoendoscopic evaluations of the nasopharynx.     

Acinic cell carcinoma in an African pygmy hedgehog (Atelerix albiventris)

Abstract: A male African pygmy hedgehog ( Atelerix albiventris ), estimated to be 3 years old, presented with exophthalmos and fixed abduction of the right eye. Radiographic examination revealed a retrobulbar tumor in the right orbital cavity. The mass was surgically resected but recurred 3 months later and the hedgehog died. There was no gross or microscopic evidence of salivary or lacrimal gland involvement of the tumor at surgery or at necropsy. The histopathologic, immunohistochemical, and ultrastructural findings were those of acinic cell carcinoma, the origin of which was unknown. This is the first known case of acinic cell carcinoma in an African hedgehog.     

Spontaneous Mammary Adenocarcinoma in a Twelve-week-old Female Sprague-Dawley Rat

Spontaneous mammary adenocarcinoma was observed in a 12-week-old female SD rat. A movable mass in the right cervical region was found at 11 weeks of age, and the rat was sacrificed the following week. The mass was located in the vicinity of the right salivary gland and measured 38 mm × 26 mm × 16 mm in gross size. It was a firm whitish mass, with a cut surface that was also whitish in appearance. Histopathologically, neoplastic cells formed glandular structures that contained secreted eosinophilic material. Ultrastructurally, similar secreted material and lipid droplets were in the cytoplasm of the neoplastic cells. Immunohistochemically, the neoplastic cells were positive for cytokeratin 8, cytokeratin 18 and estrogen receptor α. Based on these findings, the tumor was diagnosed as a mammary gland adenocarcinoma, and we therefore conclude that this tumor type can occur spontaneously in female SD rats as young as 12 weeks of age.     

Malignant mixed tumor in the salivary gland of a cat

The presence of a malignant mixed tumor, also known as a carcinosarcoma, in the salivary gland is very rare. Such tumors, which are typically aggressive, are characterized by the presence of carcinomatous and sarcomatous components. A 9-year-old neutered female domestic short-haired cat presented with swelling in the right mandibular lesion that had rapidly enlarged over the previous 3 weeks. Physical examination revealed a large, fluctuated and painless subcutaneous swelling that was associated with a firm mass. Radiographs of the head revealed a soft-tissue density that involved faint circular calcific opacity. Contrast-enhanced computed tomography revealed that the peripheral capsulated cystic area had a contrast enhanced region without bone lysis. The cat received a total excision of the mass and postoperative radiotherapy. Histopathological analysis of the mass revealed that it was a malignant mixed tumor. Metastasis to the lung was discovered 7 weeks later, at which time treatment was stopped.     

Parotid salivary gland adenocarcinoma with bilateral ocular and osseous metastases in a dog

A case of primary parotid salivary gland adenocarcinoma is described in a three-year-old entire female great dane. The presenting complaint was sudden onset blindness concomitant with the development of bilateral hyphaema and anterior uveitis. A soft-tissue swelling of the left subaural region and right forelimb lameness were also present. A definitive diagnosis of primary parotid salivary gland adenocarcinoma with bilateral ocular metastases was made on post mortem examination. Metastases were also present in the right proximal humerus, left and right prescapular lymph nodes, left axillary lymph node, left retropharyngeal lymph node, bronchial lymph nodes and all lung lobes.     

Experimental rabies in skunks: mechanisms of infection of the salivary glands.

Striped skunks (Mephitis mephitis) were inoculated into the right submandibular salivary gland with street rabies virus. They were killed at various times after inoculation and several tissues were examined by immunofluorescence and light microscopy. Right and left superior cervical, nodose and trigeminal ganglia, medulla oblongata and at least three regions of right and left submandibular salivary glands were examined by the fluorescent antibody technique. Intracerebral titrations of salivary gland suspensions were made in weanling white Swiss mice. Immunofluorescent material (inoculum) was detected in septa and connective tissue surrounding secretory units of the right submandibular gland immediately after inoculation, but otherwise antigen was not detected in either right or left submandibular glands without coincident antigen in the medulla oblongata. This occurred first on day 12 in areas of the gland remote from the inoculation site. Titers of virus were low at this time. Serum neutralizing antibodies occurred by day 7 in a few skunks. The time of development and distribution of antigen strongly suggest that, even after direct inoculation, neural networks are necessary for development of widespread infection of the salivary gland. The early occurrence of serum neutralizing antibodies in some of the skunks suggests that the immune response was activated by virus in the inoculum since immunofluorescence was not detected in any tissue at this time.     

Zygomatic salivary cyst with mucocele formation in a cat

An eight-year-old neutered male domestic shorthalr cat had a zygomatlc salivary cyst with associated mucocele formation. A fluctuating swelling developed ventral to the right eye, causing bulging of the lower eyelid, and a corresponding swelling was present in the caudal vestibule of the oral cavity. Cytological examination of the fluid obtained from asplratlon of the swelling was consistent with the appearance of saliva. A tentative dlagnosls of zygomatlc salivary mucocele was made. Surgical exploration and resectlon of the swelling demonstrated the presence of a multliobular cystic zygomatlc salivary gland. The histopathological appearance of the resected tissue was Interpreted as an Inflammatory reaction to mucus derived from a muitllocular salivary cyst.     

Resection of a cervical tracheal bronchus in a foal

A 3-day-old Thoroughbred foal developed a large, air-distended, midcervical swelling that was diagnosed as a congenital tracheal bronchus with associated ectopic lung tissue. Clinical signs consisted of a compressible air-filled sac that enveloped the trachea. The nature and extent of the defect were evaluated endoscopically and radiographically. Surgical resection of the bronchus and associated air-filled sac resulted in a functionally and cosmetically acceptable outcome.     

Modified lateral orbitotomy for vision-sparing excision of a zygomatic mucocele in a dog

A 1-year-old Shar Pei presented for recent-onset exophthalmos and right peri-ocular facial swelling. Physical examination revealed the facial mass was of soft-tissue consistency and nonpainful to the dog. Due to inability to retropulse the globe during ophthalmologic examination, it was suspected the mass had impinged into the orbit, resulting in rostral displacement of the globe. Anatomic location suggested the lesion was probably associated with the zygomatic salivary gland. Fine-needle aspiration and subsequent cytological evaluation of fluid extracted from the facial mass was consistent with a diagnosis of zygomatic mucocele. Computed tomography imaging confirmed a single fluid-filled mass was resulting in both the facial distention and the exophthalmos. A modified, lateral orbitotomy surgical approach was selected for excision of the lesion to provide ventral exposure to the orbit, while minimizing trauma to the globe and supporting structures. Histopathology of the excised lesion confirmed a diagnosis of zygomatic mucocele. This case demonstrates utilization of a modified lateral orbitotomy for effective surgical management of a zygomatic mucocele in a dog, with preservation of vision and absence of any significant postoperative complications.     

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.     

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.     

Oncocytoma in the mandibular salivary gland of a cat

A cat was referred for investigation of a soft tissue mass caudal to the left mandible. Initial investigations suggested a malignant salivary gland tumour, and the mass was removed by extracapsular resection of the mandibular gland. Histopathology showed an oncocytoma within the salivary gland. An oncocytoma is a neoplastic transformation of oncocytes. Oncocytes are cells with a small nucleus and intense eosinophilic granular cytoplasm due to numerous mitochondria, which proliferate during ageing in exocrine and endocrine glandular tissues. Physiological proliferation occurs next to oncocytosis, oncocytoma, and oncocytic carcinoma. This is the first report of an oncocytoma in a feline mandibular salivary gland, and the first report of long-term survival after surgical removal.     

Cervical teratoma in a dog

A young adult boxer dog was examined for a painless swelling in the left cranial cervical area that was refractory to antibiotic therapy. Ultrasound examination revealed a hypoechoic mass abutting the rostrolateral aspect of the left mandibular salivary gland. The cystic mass was excised and was found to extend through the capsule of the salivary gland and appeared to be confluent with the glandular tissue at this point. Histopathological examination of the excised tissue demonstrated tissue from all 3 germinal layers. There was no indication of malignancy and the mass was diagnosed as a benign cervical teratoma. Hypotheses regarding the origin of teratomas in general are discussed and the origin of the teratoma in this case is suggested.     

Adenocarcinoma of the parotid salivary gland in a cow

A 6‐year‐old Girolando dairy cow was presented for evaluation of a large subcutaneous facial mass. Fine‐needle aspirates of the mass contained many neoplastic cells with high nuclear:cytoplasmic ratios arranged in sheets and loosely cohesive clusters with streaming erythrocytes and neutrophils in the background. Neoplastic cells were 13–25 μm in diameter and were round to cuboidal with variably distinct borders. Based on the signalment, anatomic location, and cytologic findings, differential diagnoses included salivary adenocarcinoma, squamous cell carcinoma, and mucoepidermoid carcinoma. The cow was euthanized and a necropsy was performed. The primary neoplasm arose from the left parotid salivary gland and meastatic tumor was found in the regional lymph nodes and lung. Histologically, the tumor was composed of anastomosing and irregular solid islets surrounded by scant stroma. Cells were negative for periodic acid‐Schiff (PAS), PAS‐diastase, and Alcian blue pH 2.5 stains, used to detect mucin. On immunohistochemical analysis, neoplastic luminal salivary gland cells expressed cytokeratin, but not S100, α‐smooth muscle actin, or vimentin. Peripheral cells of neoplastic islets were immunoreactive for p63. The final diagnosis was nonsecretory adenocarcinoma of the parotid salivary gland.