Enucleation or exenteration in two dogs with previous parotid duct transposition: parotid duct ligation versus reverse parotid duct transposition

Two dogs with previous parotid duct transpositions presented with unrelated ocular disease. In both cases, ophthalmic examination revealed the need for enucleation or exenteration. In case 1, systemic coccidioidomycosis was diagnosed with panuveitis and secondary glaucoma of the left eye. In this case, the parotid duct was ligated at the time of enucleation to stop salivary secretions. This dog encountered morbidity in the form of a sialocele that did not resolve for 11 months. In case 2, ultrasound and computed tomography revealed a discrete mass within the left medial orbit that was suspected to arise from the nictitating membrane. A combination of exenteration and parotid duct transposition reversal was performed to avoid morbidity associated with ligation of the parotid duct. The dog encountered no complications from this novel procedure. This case report represents the first report of re‐routing a transposed parotid duct from the ventral conjunctival sac back to the mouth at the time of enucleation or exenteration in the dog.     

Parotid salivary duct sialocele associated with glandular duct stenosis in a cat

Feline parotid salivary duct sialocele is an uncommon disorder that has been previously reported in association with traumatic rupture of the duct in only two cats. Both cases were successfully treated by proximal duct ligation. We describe the successful surgical treatment of a parotid duct sialocele, secondary to spontaneous salivary duct stenosis, in an adult domestic shorthair cat. The cat was referred for assessment of a recurrent fluid-filled swelling on the left side of the face. Cytology of the aspirated fluid was consistent with serous saliva. The anatomical localisation of the lesion and the nature of the fluid were indicative of parotid gland/duct involvement. Retrograde sialography by parotid duct cannulation was unsuccessful because the left parotid duct opening was stenosed and obstructed by scar tissue. Surgical exploration revealed a parotid salivary duct sialocele, which was completely removed along with the parotid gland without complications.     

Sialography of sheep parotid and mandibular salivary glands

The anatomy of ovine salivary glands was studied on cadaver heads. The mandibular duct enters the oral cavity on the ventral surface of sublingual caruncles, which are located medial to the orifice of the ventral sublingual gland duct. The parotid gland duct enters the oral cavity on the cheek opposite the upper 2nd molar. Prior to applying sialography to live animals, the procedure was carried out on cadaver heads then the live animals were sedated, the mandibular and parotid ducts catheterized and contrast medium was injected into each gland. Lateral radiographs were made immediately after the injection. The normal sheep mandibular and parotid salivary glands have a multilobular appearance in cadaver heads, but in live animal only the ducts and their smaller branches could be identified. The mean diameter of mandibular and parotid duct were 1.4+/-0.3 mm and 3. 1+/-1.0 mm respectively. The monostomatic sublingular gland had a slender shape in the sialogram. In conclusion sialography of mandibular, parotid and sublingual salivary glands in sheep is practical and can be helpful in diagnosis of pathological conditions of these glands.     

Parotid salivary duct rupture and fistula in the dog and cat

Three dogs and one cat were diagnosed at the University of Pennsylvania Veterinary Hospital as having parotid salivary duct rupture and fistula as a result of previous surgery. Sialography confirmed the diagnosis. Two animals were treated by ligation, and two by anastomosis of the parotid duct. All four animals returned to normal after treatment.     

Traumatic injury to the parotid salivary gland or duct and the subsequent development of ipsilateral severe peripheral dental caries in two horses

This report describes two cases of unilateral traumatic injury to the parotid salivary gland or duct and the subsequent development of severe ipsilateral peripheral dental caries. Ultrasonographic examination of the parotid salivary gland and duct was indicative of parotid glandular atrophy in one case and demonstrated parotid duct obstruction in the second case. To the authors’ knowledge, the effects of the loss of function of the parotid salivary gland on the horse's dentition has not been documented and should be considered as a potential side effect of surgical ablation of the parotid salivary gland.     

Postenucleation orbital sialocele in a dog associated with prior parotid duct transposition

An orbital sialocele developed in a dog following enucleation for protracted glaucoma. This eye had historically been treated for keratoconjunctivitis sicca by parotid duct transposition approximately 5 years previously, and the duct was ligated distally at the time of enucleation. One month following enucleation, the dog presented with a fluctuant conical-shaped swelling ventrolateral to the orbital socket. Surgical exploration revealed a dilated, fibrotic distal portion of the previously transposed parotid duct, and saliva, within the enucleated orbit. The distal portion of the duct and saliva-containing tissues from within the orbit were excised. The remaining proximal normal portion of the parotid duct was re-routed into the oral cavity. Clinicopathologic and histologic examination of the excised orbital contents and dilated portion of duct revealed a sterile sample of saliva and moderate chronic periductal fibrosis. At a 6-month re-evaluation there was no evidence of recurrence of the sialocele, and the parotid duct was functional.     

Bilateral parotid duct transposition for keratoconjunctivitis sicca in a Connemara stallion

A 7‐year‐old Connemara stallion was presented with a 4 month history of blepharospasm, recurrent corneal ulcerations, mucopurulent ocular discharge, and keratoconjunctivitis sicca (KCS) in both eyes unresponsive to medical therapy. Ophthalmic examination revealed lackluster corneas, axial corneal scarring and pigmentation with associated neovascularization, and absolute KCS in both eyes. Computed tomography scan and endoscopic evaluation of the upper airway and guttural pouches revealed no structural abnormalities to indicate neurogenic KCS. The stallion was diagnosed with immune‐mediated dacryoadenitis as all other causes of KCS were excluded. Parotid duct transposition (PDT) was performed in the right eye followed by PDT in the left eye 4 weeks later. The right PDT was functional 2 years post‐operatively with significant improvement in ocular comfort and reduced corneal fibrosis and neovascularization. The left PDT developed a salivary‐cutaneous fistula over the left masseter muscle post‐operatively due to avascular necrosis of the distal parotid duct (PD). Surgical reconstruction of the PDT using an expanded‐polytetrafluoroethylene (e‐PTFE) tube graft, an e‐PTFE tube graft to autogenous caudal auricular vein graft, and an autogenous saphenous vein graft were all unsuccessful. Tear production in the left eye improved at 1 year post‐surgery as a result of long term lacrostimulant therapy, and a permanent PD‐cutaneous fistula was performed on the left PD at the level of the ventral mandible. Bilateral PDT in the horse is effective in resolving clinical signs associated with KCS; however, morbidity associated with avascular necrosis of the transposed PD may be significant and can result in surgical failure.     

Determination of parotid sulfate secretion in sheep by means of ultrasonic flow probes

The bilateral output of sulfate in parotid saliva, the relationship with its plasma level and with parotid flow, and its variation according to feeding behavior were determined in ad libitum, normal-sulfate (0.28% DM)-fed sheep (n = 6) using a transit time ultrasonic flow meter system to measure salivary flow. Ultrasonic flow meter probes were bilaterally implanted, under general anesthesia, around parotid ducts previously fitted through their oral ends with nonobstructive sampling catheters. Salivary flows were continuously recorded during 24 h, and saliva and blood samples for sulfate determinations were obtained hourly. Jaw movements were monitored with the submandibular balloon technique. The sulfate concentration in parotid saliva (mean of the group = 4.9 +/- 3.7 microg/mL) showed high variability between sheep (individual means from 0.4 +/- 0.3 to 9.3 +/- 5.9 microg/mL) and averaged 12.3% of the more stable plasma level (41.2 +/- 8.1 microg/mL). Pronounced intraindividual variations were also evident (0.1 to 26.3 microg of sulphate/mL of parotid saliva), in strong association with the fluctuations of salivary output. In 4 sheep, a decreasing exponential relationship was observed between parotid sulfate concentration and salivary secretion rate (r2 = 0.36, P < 0.01). This fact and the absence of a relationship between sulfate levels in plasma and in saliva suggest a sulfate secretory process during the passage of primary saliva through the ductal tree of the gland. The greatest rates of bilateral salivary sulfate output were observed during feeding (14.1 +/- 14.0 microg/min) and rumination (12.7 +/- 11.0 microg/min). Nevertheless, 49% of the sulfate output in parotid saliva was present during rest, as a result of the length of the resting times. The contribution of parotid sulfate to the ruminal S pool was highly variable and averaged 13.2 mg/d, representing less than 1% of the S intake. In conclusion, the accurate, reliable, nonobstructive, and bilateral salivary flow monitoring, using a previously characterized ultrasonic flow meter technique, allowed a detailed determination of the secretory dynamics of sulfate in parotid saliva, without disturbing the animal's routine or altering the physiological regulation of salivary output. The results indicated that, in the absence of S deficiency, the recycling of sulfate via saliva seems not to be a major factor in sheep nutrition.     

A new surgical method for the control of the epiphora in dogs: modified parotid duct transposition

A five-year-old, female, spayed beagle with a history of unilateral epiphora of several months' duration as a result of inadequacy of the lacrimal drainage system was treated successfully with a new surgical method of parotid duct transposition. Data from complete preoperative ophthalmological examination, surgical technique, postoperative treatment, contrast radiography and histological examination were recorded. Absence of complications and complete patency of the stoma at 30 days after surgery confirmed the validity of this new technique. The use of an anatomic duct may be advantageous compared with the current techniques of conjunctivorhinostomy, conjuntivobuccostomy and conjunctival maxillary sinusostomy for the treatment of epiphora in the dogs caused by inadequacy of the lacrimal drainage system.     

Congenital atresia of the parotid salivary duct in a 7-month-old quarter horse colt

A 7-month-old Quarter Horse colt was examined because it had had a tortuous, distended vessel on the side of its head since birth. An abnormality of the parotid salivary duct was suspected on the basis of location and course of the vessel. Atresia of the duct near the parotid papilla was diagnosed by use of contrast sialography. Surgical transpositioning was attempted, but failed because of stricture formation. Chemical ablation of the salivary gland has been used to treat traumatic rupture of the duct. It proved to be an effective and practical method of resolving the problem in this case. Cosmetic outcome was excellent, and functional problems associated with loss of the gland were not observed.     

Determination of parotid urea secretion in sheep by means of ultrasonic flow probes and a multifactorial regression analysis

For determination of the dynamics of parotid urea secretion in conscious sheep, a previously standardized transit time ultrasonic flow metering system was used to measure bilateral parotid flow. Six ewes fed for ad libitum consumption were prepared under halothane anesthesia with ultrasonic probes around both parotid ducts; these ducts were also cannulated orally. After probe encapsulation (8 d), parotid flows were recorded during 24 h, and samples of saliva and blood for urea determination were obtained hourly. Jaw movements were recorded by means of a submandibular balloon to monitor feeding behavior. Urea concentration in parotid saliva was 60 to 74% of that in plasma (a positive linear correlation existed) and was poorly influenced by the parotid flow. The amount of urea secreted with parotid saliva was directly related to the salivation rate. To calculate the urea secretion in parotid saliva, a multiple linear regression model was developed from computer-calculated parotid flows over 1-min periods and plasma urea concentration. The model was accurate because the plot of calculated vs measured values was not significantly different from the line of identity. The daily parotid urea N varied from .35 to 1.02 g among ewes. The higher urea secretion rate found during rumination and eating (1.32+/-.42 and .98 +/-.33 mg/min, respectively) vs. during rest (.60+/-.39 mg/ min, P<.05) was due to higher salivation rates (5.17 +/-1.46, 3.56+/-.90, and 2.04+/-.52 mL/min, respectively, P<.05) rather than to changes in saliva urea concentrations (saliva:plasma urea ratio = .65+/-.04, .67+/-.04, and .68+/-.03, respectively). Of the daily parotid urea output, 40.8% was secreted during rest. The contribution of parotid urea N to the ruminal N pool was relatively small (1.2 to 3.7% of the N intake, which was 23.0 to 33.6 g/d). These techniques allowed direct and precise measurements of parotid urea secretion without disturbing the animal or altering the physiological regulation of salivary secretion.     

Comparative pharmacokinetics of sulfamethazine in plasma and parotid saliva of sheep

Salivary output in sheep is large enough to be considered a physiologic body fluid compartment. The hypothesis for this work was that pharmacokinetics of sulfamethazine in saliva was similar to that in plasma. A reliable technique was developed to measure parotid salivary output. Mean output of saliva was 3.18 ± 1.04 L from a single parotid gland per day with a mean flow of 2.21 ± 0.43 mL/min. Using concentrations of sulfamethazine in parotid saliva made it possible to calculate the total passage of sulfamethazine to parotid saliva, which was calculated to be 3.5% of the total dose. Pharmacokinetic variables obtained for sulfamethazine in plasma and in saliva were closely related ( AUC 1408 μg.h/mL and AUC 1484 μg.h/mL; V d_area 0.434 L/kg and V d _area 0.374 L/kg; t _½β 4.30 h and 3.46 h, respectively) and no substantial differences were observed. The convenience of using salivary concentrations of sulfamethazine for drug monitoring is discussed.     

Severe, unilateral, unresponsive keratoconjunctivitis sicca in 16 juvenile Yorkshire Terriers

OBJECTIVE: To present ophthalmic findings, clinical data, and treatment outcomes of 16 juvenile Yorkshire Terriers with severe unilateral keratoconjunctivitis sicca. RESULTS: Each of the 16 dogs exhibited extreme unilateral dryness associated with blepharospasm, mucoid discharge, and corneal vascularization. Ages of affected dogs at presentation ranged from 5 months to 4 years. Mean Schirmer tear test (STT) result for affected eyes was 1 mm/min. Topical application of 0.2% cyclosporine to the affected eye was not associated with improvement in STT values in any dog. Clinical signs subjectively improved with topical application of 20% chondroitin sulfate ophthalmic solution in some dogs, and transposition of the parotid duct was performed in three dogs. Histopathologic examination in one dog failed to show evidence of orbital lacrimal gland tissue. Clinical signs, age of presentation, disease severity, and lack of response to treatment are consistent with breed-related unilateral aplasia or hypoplasia of the lacrimal gland. CONCLUSION: Lacrimal gland aplasia or hypoplasia should be considered in young dogs with severe unilateral ocular dryness, especially female Yorkshire Terriers.     

Polarized light biomicroscopic observations on the pre-corneal tear film. 2. Keratoconjunctivitis sicca in the dog

Polarized light biomicroscopy was used to examine the pre-corneal tear film in 16 dogs which were suspected of, or confirmed to be, suffering from keratoconjunctivitis sicca. One animal displayed a normal tear film, while the other 15 showed variable degrees of abnormality. The abnormal features included: contamination of the ocular surface with particulate debris and plaques of mucus, discontinuity and excessive granularity of the surface lipid film, pronounced thinning of the aqueous phase, and breakup of the tear film. After parotid duct transposition, the tear film of some animals was almost indistinguishable from normal. However, in others the surface lipid layer was thinned, discontinuous, or virtual absent. Discontinuity of surface lipid was most obvious in animals with marked salivary epiphora, and was associated with a variable amount of crystalline concretion over the ocular surface. The clinical usefulness of polarized light biomicroscopy for the diagnosis, and subsequent monitoring, of keratoconjunctivitis sicca is discussed.     

SIALOGRAPHY IN CATTLE: TECHNIQUE AND NORMAL APPEARANCE

Sialography of the bovine mandibular and parotid salivary glands was performed by injecting iodinated, water soluble contrast medium into the respective ducts. The anatomy of the above mentioned salivary glands was studied on cadaver heads. The mandibular duct enters the oral cavity on the ventral surface of the sublingual caruncles, which are located medial to the orifice of the ventral sublingual gland duct. The parotid gland duct enters the oral cavity on the cheek opposite the upper 2nd molar (Sth cheek tooth). Prior to applying sialography to live animals, the technique of catheterization, injection and radiography had to be developed, which was carried out on cadaver heads. Subsequently the technique was applied to 5 live animals. The animals were sedated, the mandibular and parotid ducts catheterized, and contrast medium was injected into each gland. Latero-lateral radiographs were made immediately after the injection. The normal bovine mandibular and parotid glands, as depicted on sialograms, have a multilobutated appearance in cadaver heads, but in the live animal only the ducts and their smaller branches could be identified. The parotid duct leaves the deep surface of the rostral end of the gland and courses along the border of the masseter muscle before it enters the mouth. The mean diameter of the duct was 4.2 ± 0.3 mm. The mandibular duct is composed of a rostral and a caudal branch. The caudal branch describes a semi circular turn prior to joining the rostral branch. The mean diameter of the main duct was 2.8 ± 0.4 mm.     

Non-immunoglobulin defense factors in canine saliva and effects of a tooth gel containing antibacterial enzymes

Selected innate: non-immunoglobulin defense factors in canine saliva were characterized and quantitated. The samples from dogs showed increased pH, higher lysozyme and salivary peroxidase activities, but lower hypothiocyanite concentration and myeloperoxidase activity when compared with human saliva. Secondly, a 1-month clinical pilot study was performed using a commercial tooth gel to determine acute and long-term changes in salivary host defense proteins. Daily application of the tooth gel did not substantially affect the concentrations of these factors in dogs with normal salivation. Our results suggest that canine saliva may be similar to human saliva, comprised of both immune and non-immune antimicrobial factors. However, as in humans, oral administration of antimicrobial proteins as reported here does not seem to benefit dogs with normal saliva secretion. Products such as the tooth gel evaluated in this study may benefit dogs with xerostomia or other clinical conditions causing decreased saliva production.     

Keratoconjunctivitis sicca: immunological evaluation of 62 canine cases

The etiology of keratoconjunctivitis sicca (KCS) in 62 dogs was evaluated, using immunologic techniques. Using direct fluorescent antibody testing, autoantibodies within the lacrimal, salivary, or pancreatic glands were detected in 5 of 8 dogs tested. Circulating antibodies to the nictitating membrane gland, main lacrimal gland, parotid salivary gland, or mandibular salivary gland were detected using indirect fluorescent antibodies in 9 of 31, 3 of 31, 5 of 31, and 5 of 31 sera, respectively. Using radial immunodiffusion, hyper-gamma-globulinemia was detected in 21 of 30 dogs with KCS. Antinuclear antibodies, primarily in a nucleolar pattern, were demonstrated in 20 of 50 dogs with KCS. Lymphocytic infiltrates were evident in 5 of 9 labial salivary biopsies, 2 of 4 parotid gland specimens, 2 of 4 mandibular gland specimens, and 2 of 3 thyroid gland specimens taken from dogs with KCS. Autoimmune diseases had been previously documented in 4 of 62 dogs. Twenty-five of the 62 dogs (40%) had concurrent problems indicative of an underlying immunologic disorder.     

Histo-ontogenetic study of the parotid salivary gland of Indian buffalo

The present study was aimed at elucidating the histogenesis of parotid gland of buffalo. The study was carried out on buffalo foetuses (n = 36), during different stages of prenatal life. The foetuses were categorised into three groups based on their curved crown rump length (CVRL). The primordial anlage of parotid salivary gland was evident at 40th day of development whereas the primary ducts, in the form of cords, were first observed at 81st day of prenatal life. The capsule formation as well as the lobulation of the gland was initiated at 127th day. At 141st day, the duct system of gland was completed. The terminal tubules attained the structure of acini at 167th day. The myoepithelial cells first appeared as flattened basal cells initially around the developing acinar cells at 167th day. The typical compound tubulo-acinar nature of the gland was first observed at 185th day. Purely serous acinar cells were seen from 185th day onwards. The micrometrical studies revealed that the mean diameter of acinar cells, intercalated ducts, striated ducts and large ducts increased with the advancement of age. The serous acinar cells were devoid of acidic as well as neutral mucopolysaccharides in prenatal age groups; however, large ducts with goblet cells exhibited positive reaction. Combined PAS-AB method revealed mixed reaction in acinar cells as well as in large ducts. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue; however, phospholipids were observed in the cell membrane of secretory cells and ducts.     

Parotid salivary duct mucocoele and sialolithiasis following parotid duct transposition

An 11-year-old, female neutered English springer spaniel presented with recurrent episodes of mucopurulent discharge from the right eye, 17 months after parotid duct transposition, culminating in the development of a swelling over the infraorbital area. A diagnosis of parotid duct obstruction with resulting rupture of the duct and sialocele was made. On exploratory surgery, three sialoliths were removed from various sites within the duct. Surgical repair of the duct restored normal saliva flow.