Anatomy of the nasolacrimal duct in Persian cats determined by computed tomographic dacryocystography.

OBJECTIVE: This study sought to describe the anatomical characteristics of the nasolacrimal duct of Persian cats as observed by computed tomographic dacryocystography. ANIMAL STUDIED: Ten cats weighing 3-6 kg (three live cats and seven cadaveric specimens). PROCEDURES: The animals were submitted to bilateral computed tomographic dacryocystography, totaling 20 nasolacrimal ducts. Dorsal, sagittal, and transverse planes were studied. Two additional skulls were also dissected following latex injection into the nasolacrimal duct. The length and width of the nasolacrimal duct and lacrimal canaliculi, and the distance between the nasolacrimal duct and the root of the upper canine tooth at the point of closest proximity were measured. RESULTS: The nasolacrimal duct followed a convoluted course, particularly in the middle and rostral portions. Duct stenosis (width reduction equal to or >75%) and dilations (width increase equal to or >50%) were also detected, particularly in the rostral portion. Nasolacrimal duct length and width ranged from 1.3 to 1.5 cm and 1.5 to 2.3 mm, respectively. Mean lacrimal canaliculus length and width corresponded to 3.1 mm and 0.4 mm, respectively. Mean distance from the nasolacrimal duct to the canine tooth was 2.4 mm. The root of this tooth interfered with the course of the nasolacrimal duct. CONCLUSION: This study provided anatomical information for clinical assessment of the nasolacrimal drainage system in Persian cats.

Use of 1% polidocanol and pre- and post-computed tomography for treatment of a suspected nasolacrimal duct cyst in a dog.

OBJECTIVE: To describe the efficacy of the sclerosing agent 1% polidocanol in the treatment of a suspected nasolacrimal duct cyst in a dog. ANIMAL STUDIED: A 5-year-old castrated male Golden Retriever with chronic epiphora of the right eye. PROCEDURES: Ocular examination revealed epiphora and a negative Jones test of the right eye and was otherwise normal. Computed tomography with dacryocystography confirmed a cystic structure in the right ventral orbit that extended into the caudal nasal cavity adjacent to the orbit, causing partial physical obstruction of the right nasolacrimal duct. Cytologic analysis of fluid from the lesion was supportive of a diagnosis of a cyst. One percent polidocanol (compounded, People's Custom Rx, Memphis, TN) was injected into the cyst. RESULTS: Epiphora was resolved by two weeks post-injection. Repeated computed tomography with dacryocystography was performed 8 months post-injection, revealing complete resolution of the cyst and demonstrating mild enophthalmos of the right globe. CONCLUSIONS: Intralesional 1% polidocanol therapy was successful in resolving a suspected nasolacrimal duct cyst in a dog.

Dacryocystitis following a nasolacrimal duct obstruction caused by an ectopic intranasal tooth in a dog.

PURPOSE: To describe a nasolacrimal duct (NLD) obstruction secondary to an ectopic tooth in a 5-year-old male Border collie. The dog was presented with a 1-month history of mucopurulent discharge from the left eye (OS) preceded by a lifelong history of epiphora OS. Treatment with neomycin/polymyxin B/dexamethasone ophthalmic solution had not improved the clinical signs, and the NLD was not patent when irrigated by the referring veterinarian. METHODS: A complete ophthalmologic examination was performed followed by dacryocystorhinography and computed tomography (CT). RESULTS: The ophthalmologic examination revealed marked mucopurulent discharge, mild conjunctivitis, slightly elevated STT measurements, and a negative Jones test OS. Both nasolacrimal puncta OS could be cannulated without resistance for approximately 1.5 cm. Upon irrigation, copious amounts of mucopurulent discharge were exited through the corresponding punctum, while no fluid could be detected at the nares. Dacryocystorhinography was performed. Radiographs revealed an ectopic left canine tooth within the left nasal cavity. A cystic dilation of the NLD was observed proximal to the ectopic tooth. Computed tomography was performed to determine the exact position of the tooth and possible involvement of adjacent structures; CT confirmed the previous imaging findings. Treatment with systemic antibiotics, NSAIDs, and ofloxacin ophthalmic solution led to resolution of the clinical signs within several days. Surgery was declined by the owner. CONCLUSION: This is the first case report describing a blocked NLD due to an ectopic tooth in a dog. Ectopic teeth should be included as a differential diagnosis in cases of dacryocystitis and chronic epiphora in dogs.

Iatrogenic nasolacrimal duct obstruction following tooth extraction in a cat.

A 10-year-old DSH cat was referred for a dental evaluation and extraction procedure. Subsequently, the animal developed an acute onset of ocular discharge. Ophthalmologic examination revealed presence of unilateral ocular mucoid discharge leading to a diagnosis of epiphora secondary to nasolacrimal duct obstruction. Dacryocystorhinography was performed and confirmed the presence of a nasolacrimal duct obstruction, presumably acquired after an invasive dental procedure. Additionally, a vinyl cast in situ study of the nasolacrymal apparatus was performed to demonstrate the route of the nasolacrimal duct in the cat and its relationship to oral dental structures. This report documents an unusual case in which excessive inflammation/edema following tooth extraction caused acute epiphora secondary to extraluminal compression of the distal nasolacrimal duct.

Case series: Computed tomography (CT) demonstrates lacrimal canal involvement in koalas (Phascolarctos cinereus) with maxillary incisor dental disease.

Dental disease is common in wild and captive koalas. Effective treatments are limited and dental disease may not be recognised until it is quite severe. We describe the appearance of varying severities of dental disease on computed tomography (CT) images in a case series of six koalas. This case series demonstrates the use of CT to detect both mild and severe dental disease in koalas. The study also documents the normal CT appearance of the nasolacrimal duct in the koala. The only clinical abnormality in koalas with the mildest dental disease was ocular discharge. Computed tomography findings associated with ocular discharge were periapical lysis of first maxillary incisors, lacrimal canal remodelling and subsequent nasolacrimal duct obstruction. Dental disease should be a differential diagnosis for ocular discharge in koalas and CT examination enables visualisation of early stages of dental disease.

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.

Calcification associated with the nasolacrimal system of a horse: case report and mineralogic composition.

A 12-year-old Paso Fino mare was evaluated for a chronic nasal and ocular discharge. A calcification was identified eroding through the nasal mucosa of the middle meatus. Differential considerations for this mass included dacryolith, nasal calculus, or calcified tooth root abscess. Anatomical location and case history and progression supported a dacryolith. Following removal, the calculus was submitted for mineralogic analysis. The calculus was primarily carbonate hydroxylapatite (Ca10(PO4)3(CO3)3(OH)2) with a minor NaCl halite constituent. Dacryoliths, or nasolacrimal calculi, are an uncommon occurrence in animals, and sparsely reported in humans. The etiopathogenesis of dacryolith formation is unknown. The objective of this article was to report the first case report of an equine nasolacrimal system dacryolith and its mineralogic composition.

Miscellaneous conditions of the equine head.

Nutritional secondary hyperparathyroidism is associated with horses that are fed diets with an imbalance of calcium and phosphorus or diets containing oxalates. Clinical signs include a shifting lameness, with tenderness of the joints, reluctance to move, or a stiff, stilted gait. Some horses may have broadening of the nasal bones, enlargement of the maxilla and/or the mandible, or a ridge over the nasal bones. Diagnosis may include physical examination findings; analysis of feed; and clinical pathologic data, which may include normocalcemia, normal to increased serum phosphorus, and increased fractional excretion of phosphorus (normal FxP < 0.5%). The primary objective of therapy is to correct the nutritional calcium to phosphorus imbalance. Sialoliths are calcific concretions that develop in the salivary gland or duct. Therapy generally involves surgical removal, and associated complications are uncommon. Obstruction of the nasolacrimal duct occurs most commonly secondary to intraluminal foreign material, although congenital atresia may occur. Clinical signs include epiphora, conjunctivitis, and mucopurulent discharge. Foreign material is often removed by retrograde saline flush and atresia is resolved by surgery.