The course of the nasolacrimal duct in brachycephalic cats

Casts of the nasolacrimal duct system were obtained from 50 euthanised cats including brachy-, meso- and dolichocephalic breeds. The course of the nasolacrimal duct, which was assessed radiographically and gross-anatomically, was strongly related to the shape of the skull. In meso- and dolichocephalic cats the nasolacrimal duct formed a dorsally opened arch with the descending part being directed rostroventrally. The main part of the duct passed the nasal cavity in a rather horizontal course parallel to the hard palate and was located ventrally to the lacrimal foramen. However, foreshortening of the face was associated with a right-angled or even acute-angled alignment of the duct. In higher degrees of brachycephaly the main part of the duct ascended beyond the level of the lacrimal foramen and passed the nasal cavity dorsal to the level of the lacrimal foramen. This specific course of the nasolacrimal duct in brachycephalic cats was consistent with a steeper alignment and attachment of the maxilloturbinate. Accessory orifices of the nasolacrimal duct opening into the nasal cavity had never been observed. The present results strongly suggest that the specific course of the nasolacrimal duct in brachycephalic cats might hinder the drainage of the lacrimal fluid irrespective of the diameter of the lumen of the nasolacrimal duct system.     

Bilateral intraocular glandular choristomas in a Thoroughbred foal

Intraocular choristomas are rare anomalies in domestic animals and are often associated with multiple ocular malformations. A Thoroughbred foal presented for ocular abnormalities and was diagnosed with microphthalmia, corneal dermoids, severe anterior segment dysgenesis (including glandular choristomas), aphakia, retinal dysplasia, and optic nerve hypoplasia. Morphological, histochemical, and immunohistochemical comparisons were made between ocular choristomatous tissues from this foal and lacrimal gland, third eyelid gland, nasopharynx, trachea, and lacrimal sac/nasolacrimal duct from normal horses. Morphologically the choristomatous tissues (glands and epithelium lining the anterior segment) were most similar to the lacrimal sac. Histochemistry of glandular components found the glands associated with the lacrimal sac/nasolacrimal duct to be serous, as was the glandular intraocular choristomas. Our findings suggest that the origin of intraocular glandular choristomas in this case is from the lacrimal sac.     

Acquired canaliculocele with intranasal extension in a dog

To describe a case of a nasolacrimal canaliculocele with intranasal extension in a dog. A 6‐year‐old neutered female Jack Russell Terrier was referred to the Centre Hospitalier Vétérinaire des Cordeliers for a slowly enlarging mass adjacent to the medial canthus of the right eye of 5 months duration. Ophthalmic exam, ultrasound, fine needle aspiration, dacryocystorhinography and computerized tomography examinations were performed. Rhinoendoscopic treatment with marsupialisation of the endonasal canaliculocele was performed. Physical examination revealed a 3 cm diameter, subcutaneous mass beneath the medial canthus of the right eye, with a defect in the maxillary bone below. Dacryocystorhinography demonstrated blockage at the level of the nasolacrimal duct. Fine needle aspiration confirmed the cavitary nature of the lesion. During rhinoendoscopy, a mass containing watery fluid was found. Following marsupialisation with a large mass wall resection, the lacrimal drainage system irrigated freely in the nasal chamber. The communication of the lumen of the diverticulum with the lumen of the superior but not the inferior canaliculus was clearly demonstrated during endoscopy. Given negative immunohistochemical staining for smooth muscle actin and desmin, nasolacrimal dacryocele appears to be the most likely diagnosis. Histological examination confirmed that no goblet cells were present in the wall of the diverticulum, which is consistent with the canaliculus rather than the lacrimal sac. Complete resolution was observed without recurrence one year after surgery. Despite its rarity, a canaliculocele should be considered in adult dogs with nasolacrimal duct obstruction. Marsupialisation seems to be the appropriate therapy.     

Endoscopic examination of the nasolacrimal duct in ten horses

Reasons for performing study: No endoscopic examination of the nasolacrimal duct has been described before. In contrast with other imaging techniques, endoscopy provides a direct inspection of the intralumen and ductal mucosa in standing sedation. Objectives: To provide a reference against which the endoscopic and clinical features of obstructive nasolacrimal disease in the horse may be compared. Methods: Endoscopic examination of the nasolacrimal duct was performed in 10 French Thoroughbred bay mares with a 3 mm shaft diameter flexible fibrescope. The duct was divided into 3 zones (1, 2 and 3) from the nostril to the lacrimal sac. Results: Endoscopic examination of the nasolacrimal duct appeared to be quite easy to perform in Zones 1 and 2, while the ease or difficulty of examining Zone 3 depended on the weight and size of the horse for the position of the endoscope in the lacrimal canal. Conclusions: Endoscopic inspection has provided the possibility of a novel diagnostic approach to conditions of the nasolacrimal duct in horses. Potential relevance: Endoscopic examination of the nasolacrimal duct could help to diagnose and treat nasolacrimal diseases by performing sample withdrawal and duct irrigation.     

Anatomic and radiographic studies of the lacrimal drainage system in sheep (Ovis aries)

The lacrimal drainage system of the sheep (Ovis aries) was studied, using radiographic and anatomic techniques. The straight course of the nasolacrimal duct and the adequate diameter of different parts of the system facilitates radiography and catheterization of the lacrimal drainage system.     

Surgical treatment of recurrent dacryocystitis secondary to cystic dilatation of the nasolacrimal duct in a dog

A 3-year-old, castrated male golden retriever was presented for evaluation of recurrent ocular discharge of 4 months' duration from the left eye. Dacryocystorhinography was performed and demarcated a cystic dilatation of the left nasolacrimal duct with obstruction of the duct distal to the cystic cavity. Surgical exploration of the left maxillary sinus was performed to confirm the diagnosis and reestablish drainage into the nasal cavity. Recovery was uneventful, and the dog has been asymptomatic for >36 months postoperatively. This report documents the third published case of surgical treatment for cystic dilatation of the nasolacrimal duct.     

Epistaxis in two horses with dacryohemorrhea.

Unilateral epistaxis in 2 horses was caused by inflammation of the distal portion of the lacrimal system. The origin of epistaxis was identified during physical examination by observing hemorrhage emanating from the nasal opening of the nasolacrimal duct. Dacryohemorrhea caused by bacterial infection was successfully treated with antibacterial drugs administered systemically and instilled into the lacrimal system.     

Purulent dacryocystitis (nasolacrimal duct drainage) secondary to periapical tooth root infection in a donkey

Periapical tooth disease in the equid has been extensively described. Rostral cheek tooth abscessation usually leads to external facial swelling, and in some cases, nasal drainage. Periapical infection of the caudal cheek teeth usually results in maxillary empyema and sinusitis. This case report describes a donkey with periapical tooth root infection of the left 3rd maxillary premolar (207) diagnosed with computed tomography, which drained exclusively into the adjacent/collateral nasolacrimal duct.     

A method of surgical correction of glaucoma in a dog

A new surgical technique is described for the attempted relief of glaucoma in a dog. To achieve aqueous drainage a Supramid thread was placed in the anterior chamber, threaded subconjunctival^ across the globe and inserted into the nasolacrimal duct via the dorsal lacrimal punctum. It is hoped that the level of success achieved in this one case will prompt others, to investigate the nasolacrimal duct as a possible drainage route for aqueous fluid.     

Orbito-nasal cyst in a young European short-haired cat

Purpose To describe a case of an orbito‐nasal cyst in a cat. Procedure An 18‐month‐old male European short‐haired cat was presented to the Ophthalmology service of the Vetsuisse Faculty, University of Zurich for a subcutaneous swelling in the medial canthal region of the right eye (OD). Ophthalmologic, ultrasound and CT examinations, and fine needle aspiration were performed. After lesion excision, the removed tissue was submitted for histopathology. CT examination was repeated 5 months after removal of the cyst. Results Ophthalmologic examination revealed a large fluctuant swelling inferonasal to OD. Despite patent lacrimal puncta, only the first few mm of the lacrimal canaliculi could be cannulated. A normal globe with moderate enophthalmos was present. Ultrasound examination showed a well‐defined lobulated cyst‐like structure in the right orbit, inferonasal and anterior to the eye. CT examination revealed extension of this lesion through the medial orbital wall into the right nasal cavity. Fine needle aspiration confirmed the cystic nature of the lesion. An orbito‐nasal cyst was diagnosed. The orbital part of the cyst was dissected from the surrounding tissue and excised from the periosteum in the medial orbital wall defect. Part of the maxillary bone was removed to allow removal of the cyst from the nasal cavity. Histologically, the cyst wall consisted of a single to multilayered, mostly cuboidal epithelium and surrounding connective tissue. Follow‐up revealed a good functional result and no recurrence 7 months after cyst removal. Conclusions Similar orbito‐nasal cystic structures were reported in dogs but not in cats.     

Lacrimal bone agenesis in a dog

A 20-month-old neutered male dachshund dog was referred because of a 10-week history of swelling close to the medial canthus of the left eye. Recurrence of the lesion and cytological appearance of the fluid content were suggestive of inflammation. Computed tomography revealed a triangular-shaped bone defect in the skull deep to the lesion. Computed tomography dacryocystography demonstrated contrast medium pooling within the maxillary recess and nasal cavity rather than filling the lacrimal duct. Lacrimal bone agenesis was diagnosed.Key clinical message:Congenital skull including lacrimal bone agenesis may be responsible for swelling of the medial canthus of the eye and computed tomography dacryocystography is helpful in making a diagnosis.     

COMPUTED TOMOGRAPHIC FINDINGS OF FUNGAL RHINITIS AND SINUSITIS IN CATS

The computed tomographic (CT) findings of fungal rhinitis/sinusitis in cats were characterized. The CT images of 10 cats ranging in age from 7 to 13 years were examined. The mean age was 10.8 years and all were neutered males. Nasal aspergillosis was diagnosed in five cats, cryptococcosis in three cats, hyalohyphomycosis in one cat, and trichosporonosis in one cat. Bilateral disease was present in eight cats, seven had abnormal soft tissue attenuation in two-thirds of the nasal cavity, and six had turbinate lysis. Seven cats had also lysis of the hard palate, nasal septum, or frontal bone. One cat had lysis of the cribriform plate. Five of the nine cats whose lymph nodes were imaged had lymph node enlargement. There was contrast medium enhancement in the nasal cavity in all cats, with either a primarily peripheral rim or heterogeneous pattern. There appears to be an overlap of clinical signs, age, and CT features of cats with nasal neoplasia and those with fungal rhinitis/sinusitis.     

Nasolacrimal obstruction caused by root abscess of the upper canine in a cat

A 10‐year‐old, castrated male domestic short hair cat was presented to the Small Animal Clinic at the Western College of Veterinary Medicine with a presenting complaint of chronic, ocular discharge from the left eye. Ocular examination confirmed epiphora and mucopurulent discharge but there were no apparent reasons for the ocular discharge, and nasolacrimal obstruction was suspected. The cat had swelling of the left side of the face, severe periodontal disease and a fractured upper left canine tooth with pulpal exposure. Dacryocystorhinography revealed narrowing of the nasolacrimal duct above the root of the fractured upper left canine and dental radiographs showed a severe periapical lucency at the apex of the upper left canine tooth. The fractured canine tooth was removed. Subsequently, the ocular discharge and facial swelling resolved. After 2 years, the epiphora has never reoccurred. This is a noteworthy case because a suspected root abscess resulted in extralumenal compression of the nasolacrimal duct, which shows the importance of a thorough oral examination when nasolacrimal obstruction is evident.     

Three-dimensional image analysis of a head of the giant panda by the cone-beam type CT

The cone-beam type CT (Computed Tomography) enabled us to collect the three-dimensional (3D) digitalized data directly from the animal carcass. In this study, we applied the techniques of the cone-beam type CT for a carcass head of the giant panda (Ailuropoda melanoleuca) to obtain the 3D images easily without reconstruction process, and could morphologically examine the sections from the 3D data by means of non-destructive observations. The important results of the study represent the two following points. 1) We could show the morphological relationships between the muscles of mastication and the mandible in non-destructive status from the 3D data. The exact position of the coronoid process could be recognized in the rostro-lateral space of the temporal fossa. 2) By the serial sections from the 3D data sets, the morphological characteristics in the nasal cavity were detailed with high resolution in this rare species. The nasal concha was well-developed in the nasal cavity. The ethmoidal labyrinth was encountered immediately caudal to the nasal cavity and close to the region of the olfactory bulb. The ethmoidal labyrinth consisted of the complicated osseous structure in this area. The data will be useful to discuss the olfactory function in the reproduction behavior of this species.     

The nasolacrimal duct of the mule: Anatomy and clinical considerations

This study investigated the location of the nasolacrimal orifice (NLO) and course of the nasolacrimal duct in the mule using visual examination, gross dissection and computed tomography (dacryocystography [CT‐DCG]) and concluded that the location of the NLO is distinct from that described for horses and donkeys and is easily located, by visual examination alone, within the internal cutaneous tissue of the lateral wall of the external nares. The course of the nasolacrimal duct caudal to the nasal vestibule is similar to that of the horse.     

Endoscopic management of a cystic naso-lacrimal obstruction in a dog

A young adult Dachshund was presented with a cystic obstruction of the nasolacrimal duct causing maxillo-turbinate destruction but no epiphora. The lesion was demonstrated by dacryocystorhinography and identified on nasal endoscopy which also permitted the successful creation of a permanent fistula without resort to invasive surgery. Histological examination of the cystic wall of the duct showed normal turbinate structures replaced by chronic inflammatory tissue.     

Computed tomographic-dacryocystography (CT-DCG) of the normal canine nasolacrimal drainage system with three-dimensional reconstruction

The aims of the study were (1) to quantify the influence of selected imaging parameters on the image quality (slice thickness, mAs, and beam orientation) defining optimal conditions for scan protocols and (2) to evaluate the benefits of the 3D reconstruction techniques for visualization of NDS structures in dogs. CT-DCG was performed bilaterally in 32 heads of dogs. CT transverse images were obtained using a combination of two slice thickness values (0.8 mm and 2 mm) and two mAs values (50 mAs and 300 mAs). Two beam projection orientations were also tested: transverse plane (perpendicular to the hard palate) and oblique to the hard palate. Three-dimensional images were obtained using Volume Rendering (VR). Transverse beam projection proved to be superior for the assessment of the inferior and superior lacrimal canaliculi and lacrimal sac. In this study, there was no statistical difference regarding mAs values (50 mAs and 300 mAs) and slice thickness values (0.8 mm and 2 mm). Three-dimensional images were helpful for the assessment of topographic relationship between nasolacrimal structures and cranial landmarks.     

Canine and feline primary ocular bacterial infections.

Bacterial infections are frequently associated with diseases of the eyelids, cornea, and conjunctiva. Animals sustaining KCS commonly have bacterial infections of the external eye owing to a lack of antimicrobial properties present in the normal tearfilm. Infection can occur in the nasolacrimal duct or lacrimal sac, which is referred to as dacryocystitis. Severe corneal ulcers are frequently infected with bacteria, especially Pseudomonas sp. Three new topical ophthalmic antibiotics have recently become commercially available: ciprofloxacin, norfloxacin, and ofloxacin.     

Differential diagnoses,investigation, and management of a periocular swelling close to the nasolacrimal duct in a horse – A case report of Dacryops

To describe the differential diagnoses, investigation, and management of a periocular swelling close to the nasolacrimal duct in a horse that was consistent with a nasolacrimal duct dacryops (lacrimal cyst). A 16‐year‐old gelding, Connemara cross presented with a history of a periocular swelling rostroventral medial to the right eye that had been sampled by the referring veterinary surgeon. A cystic lesion was diagnosed following standing computed tomography. Surgical removal of the cystic lesion was performed, and the tissue was submitted for histopathologic and immunohistochemical examination. Surgical removal of the cyst was curative, and there was no recurrence of clinical signs 7 months later. There was a small amount of mineralized material in the center of the cyst. Histopathologic and immunohistochemical examination confirmed a nasolacrimal duct cyst. Dacryops can form in horses as well as other species and appears to have a favorable outcome if surgically removed.