Nasal dermoid sinus in an American cocker spaniel

An American cocker spaniel was presented for a subcutaneous mass and draining tract located between its eyes. Contrast radiography and surgical excision showed communication of the tract with the left frontal sinus and rostral cerebral dura, respectively. A dermoid sinus was diagnosed by a combination of gross and histologic findings.     

Nasal dermoid cyst extending through the frontal bone with no sinus tract in a Dalmatian

A Dalmatian was presented with a subcutaneous swelling in the dorsal midline between the eyes. No opening in the skin was identified at the dorsal nasal planum and there was no discharge. Positive contrast sinography showed contrast material filling a cyst that extended to the frontal bone. At surgery, the cyst had a tubular shape and was embedded in a fibrous dermal tissue strand running into the bony nasal septum. The nasal dermoid sinus cyst was surgically removed by limited dorsal rhinotomy, followed by excision of the remaining strand from a bony recess in the lamina perpendicularis ethmoidalis. It is proposed that this nasal dermoid cyst that extends through the frontal bone with no sinus tract is classified as a type V subtype c.     

Nasal rhinosporidiosis in the dog

Rhinosporidiosis was diagnosed in six dogs from the southeastern United States. All six dogs had unilateral nasal polyps with multiple small white sporangia visible beneath the surface. Microscopically, the polyps consisted of organisms and fibrovascular tissue with a surface of columnar or squamous epithelium. Juvenile sporangia were unilamellar, 15-75 microns in diameter, nucleated, and accounted for about 65% of sporangia seen. Approximately 5% of the sporangia were in intermediate stages of maturation, were bilamellar, 100-150 microns in diameter, and contained immature endospores. Mature sporangia comprised about 30% of the total, were usually unilamellar, 100-400 microns in diameter, and contained a mixture of immature and mature endospores. The inner layer of the wall of the intermediate sporangia and the single wall of the mature sporangia were argyrophilic and carminophilic. Ultrastructurally, the earliest stage contained a nucleus and many ribosomes, lipid droplets, and phagolysosomes. Maturing sporangia contained discrete membrane-bound, round clevage products. These structures subsequently matured to spores, each of which had a wall and contained a nucleus and many lipid droplets. The organism from one dog was cultured and grown in vitro for 7 months and is the first successful cultivation of Rhinosporidium seeberi.     

Intracranial dermoid cyst in a dog

A 7-year-old spayed bitch had a 3-year history of episodes of hind-limb weakness and ataxia. Neurologic abnormalities consisted of deficits in postural reactions, spinal reflexes, and conscious proprioception. A right-sided head tilt also was observed. Immediately after cervical radiography, CSF tap, and electroencephalography, the dog was alert, but it was found comatose the next morning and died within an hour. At necropsy, a 1.6- x 0.8- x 1.5-cm, thinly encapsulated mass was found on the left cerebellar peduncle. It had caused dorsal displacement of the left portion of the cerebellum and ventral compression of the fourth ventricle. Histologically, the mass was determined to be a dermoid cyst.     

Inheritance of dermoid sinus in the Rhodesian ridgeback

OBJECTIVES: TO define the mode of inheritance of dermoid sinus. METHODS: A chi-squared analysis was performed on data from 46 litters produced between 1990 and 2001. Data were corrected to avoid bias in the segregation ratio. RESULTS: In data from 57 litters (n=492), 82 dermoid sinus positive offspring were observed. The frequency of affected offspring in the Swedish Rhodesian ridgeback population is estimated to be between 8 and 10 per cent. CLINICAL SIGNIFICANCE: Bias in heredity pattern may be caused by undetected dermoid sinus type V. Improved clinical diagnosis of all dermoid sinus types is therefore crucial.     

A dermoid sinus in a Siberian Husky

The aim of this paper is to report a case of dermoid sinus in a Siberian Husky dog. Skin lesions were characterized by dual fistulae in the dorsal thoracic region. Surgical dissection revealed cysts (full of debris, hair and purulent exudate) connected by a fibrous cord to the first and the second thoracic vertebrae.     

A nasal dermoid sinus in an English bull terrier

A five-year-old, entire female English bull terrier was presented with a six-week history of intermittent facial swelling and nasal pain, following an incident of nasal trauma. A small opening was present at the mucocutaneous junction on the dorsal nasal planum. Examination under general anaesthesia allowed catheterisation of this opening and confirmed the presence of a tract passing caudally. Plain radiographic examination of the region was unremarkable. Positive contrast sinography demonstrated contrast material filling a midline tract that passed caudally and subcutaneously towards the nasal bone. This tract was surgically excised. Histopathological examination of the excised tissue, together with the clinical findings, led to the diagnosis of nasal dermoid sinus.     

Type IV dermoid sinus,intramedullary dermoid cyst and spina bifida in a Cane Corso

A 1-year-old male Cane Corso was presented for progressive hindlimb neurologic deficits, with a history of suspected recurrent meningitis. Physical examination and advanced diagnostic imaging findings were suggestive of a thoracic dermoid sinus extending into the dura mater, and spina bifida. After initial medical treatment, the lesion was surgically excised, and the presence of an intramedullary cyst in continuation with the dermoid sinus was confirmed, requiring partial durectomy and myelotomy for removal. Histopathological examination of the excised tissue confirmed the diagnosis of a dermoid sinus associated with an intramedullary dermoid cyst. After surgery, the dog temporarily declined neurologically but then showed progressive neurological improvement. This report describes presentation and successful surgical treatment of a type IVa dermoid sinus associated with an intramedullary dermoid cyst and spina bifida in a dog.     

Nasal and frontal sinus mucosa of the adult dog contain numerous olfactory sensory neurons and ensheathing glia

Olfactory glial cells have been the focus of much recent research interest because of their possible future use as cellular transplants in repair of spinal cord injury. Although olfactory glial cells can be collected from the olfactory bulb for in vitro culture, alternative sites would be preferable for safer surgical access. This study was designed to investigate the distribution of olfactory sensory neurons and olfactory glial cells within the canine peripheral olfactory system. Using immunohistochemistry and electron microscopy on perfused tissue we demonstrate that olfactory sensory neurons are found in both the caudal nasal and the frontal sinus epithelia. Olfactory ensheathing glia were found in the mucosa at both these sites implying that surgical access for harvesting cells for transplantation would be straightforward.     

Spinal dermoid sinus in a Burmese cat with paraparesis

A 2-year-old, male, Burmese cat was evaluated for chronic progressive hindlimb weakness, ataxia and urinary incontinence. Radiographic examination, myelography and magnetic resonance imaging defined congenital vertebral anomalies and a space-occupying intradural, extramedullary mass. A dermoid sinus was subsequently identified dorsal to the affected spine. Surgical excision of the tract necessitated a dorsal laminectomy and removal of a 1-cm diameter intradural dermoid sinus 'cyst' that contained hair and sebaceous debris. The cat recovered hindlimb function after surgery and remains asymptomatic 50 months after surgery except for a persistent inability to urinate voluntarily.     

Ganglion cysts in a juvenile dog

Ganglion cysts were diagnosed in a 4-month-old male Afghan Hound. Grossly, the subcutaneous ovoid cysts around the caudal right elbow joint and left ischiatic tuberosity had abundant mucinous fluid and internal folding. The lesions recurred twice around the elbow joint after surgical removal. Neither cyst communicated with the joint cavity. Histologically, the cyst wall consisted of inner myxomatous and outer immature connective tissue. Some parts of the cyst wall had various stages of myxoid metaplasia of collagen tissue leading to new cyst formation. Ultrastructural study revealed that cells in the myxoid metaplastic lesion had well-developed cytoplasmic secretory elements, including abundant rough endoplasmic reticulum, Golgi apparatus, and many smooth-walled vesicles. These ganglion cysts apparently resulted from the metaplasia of fibroblasts to secreting cells.     

Attempts to produce salivary cysts in the dog

Attempts were made to create salivary cysts by ligation of the mandibular salivary duct at the angle of the mandible and near the frenulum of the tongue, by rupture of the mandibular duct at the angle of the mandible and near the frenulum of the tongue, and by direct trauma to the mandibular salivary gland. Cysts were not formed as a result of the experimental procedures, but observations are made on the results obtained.     

Thymic branchial cysts in the dog and cat

Branchial cysts of the thymus were diagnosed in 15 dogs and 2 cats. The main clinical sign was dyspnea. Pleural effusion varied in degree from minimal to severe. In all animals, an encapsulated mass in the cranial mediastinal region was found to consist of multiple epithelial cysts embedded in a stroma of fibrous connective tissue, adipose tissue, and vessels. Surgical resection of the cysts was performed in 7 dogs; 3 dogs survived and were clinically normal for 18 to 36 months.     

Some aspects of interdigital cysts in the dog

Some aspects of the incidence, breed distribution, examination and the macroscopic and microscopic pathology of interdigital cysts are described. The aetiology and pathogenesis of this condition are discussed.

• (a). Ninety-five dogs (1.6 per cent) of a total of 5923 dogs were presented for examination with interdigital cysts.
• (b). The Pekingese, West Highland White Terrier and Scotch Terrier are predisposed to interdigital cysts.
• (c). The incidence of interdigital cysts in the Border Collie is very low.
• (d). Interdigital cysts occur most regularly in the 3/4, 4/5 interdigital space of one or both fore-feet.
• (e). Interdigital cysts are essentially granulomatous lesions containing abscesses and sinus tracks.
• (f). Staphylococcus aureus and β haemolytic streptococci are common secondary bacterial invaders.
• (g). Interdigital cysts probably originate from a pedal dermatitis and folliculitis.
• (h). It is suggested that the conformation of the interdigital web plays a part in the susceptibility of a dog to interdigital cyst.

Résumé. Certaines questions concernant la fréquence, la distribution d'après les races des signes cliniques et l'anatomie pathologique macroscopique et microscopique des kystes inter-digitaux sont évoqués. L'étiologie et la pathogénie de cette affection sont discutées.

• (a). 95 chiens (1,6%) sur un total de 5 923 animaux présentés à l'examen étaient atteints de kystes interdigitaux.
• (b). Les Pékinois, West Highland White Terrier et Scotch Terrier sont particulièrement prédisposés à cette affection.
• (c). La fréquence des kystes interdigitaux chez le Border Collie est très basse.
• (d). Les kystes interdigitaux s'observent avec prédilection dans les espaces interdigitaux 3/4 et 4/5 d'une ou des deux pattes antérieures.
• (e). Les kystes interdigitaux présentent essentiellement des lésions granulomateuses contenant des abcès et des trajets fistuleux.
• (f). Le Staphylocoque doré et le streptocoque β-hémolytique sont les germes d'infection secondaire les plus fréquents.
• (g). Les kystes interdigitaux tirent probablement leur origine d'une dermatite et d'une folli-culite du pied.
• (h). On estime que la conformation de la membrane interdigitale joue un rôle dans la sensibilité du chien aux kystes interdigitaux.

Zusammenfassung. Einige Aspeckte der Häufigkeit, der Verteilung auf die Hunderassen, der Untersuchung und der makroskopischen und mikroskopischen Pathologie der Interdigital-cysten werden beschrieben. Die Ätiologie und die Pathogenese dieses Zustands werden be-sprochen.

• (a). 95 Hunde (1,6%) von insgesamt 5923 Hunden wurden mit Interdigitalcysten zur Untersuchung vorgeführt.
• (b). Der Pekinese, der West-Highland-White-Terrier und der Scotch-Terrier sind für Interdigitalcysten prädisponiert.
• (c). Die Häufigkeit von Interdigitalcysten beim Border Collie ist sehr gering.
• (d). Interdigitalcysten treten am regelmässigsten im 3/4– und 4/5-Interdigitalraum einer oder beider Vorderpfoten auf.
• (e). Interdigitalcysten sind im wesentlichen granulomatöse Läsionen, die Abszesse und Fistelgänge enthalten.
• (f). Staphylococcus aureus und β-Hämolyse-Streptokokken sind häufig die Ursachen von Sekun-därinfektionen.
• (g). Interdigitalcysten werden wahrscheinlich durch Fussdermatitis und Folliculitis verursacht.
• (h). Es wird der Vermutung Amdruck gegeben, dass die Art der Ausbildung des Interdigital-gewebes eine Rolle bei der Empfindlichkeit eines Hundes fur die Entstehung von Interdigitalcysten spielt.

     

Nasal and oral masses in a dog

A 5-year-old, intact male, stray dog was presented in poor body condition, with pallor, muzzle deformity, multiple oozing fistulas with grass awns, bilateral sanguinopurulent nasal discharge and a fleshy friable mass occupying part of the hard palate. A friable mass occupying both nasal cavities was found on rhinoscopy. The dog had moderate nonregenerative normochromic-microcytic anemia, thrombocytopenia, hyperglobulinemia, and hypoalbuminemia. Cytologic preparations of the nasal and oral masses contained a neoplastic population of round cells with intracytoplasmic and extracellular vacuoles. Leishmania amastigotes also were observed, in the cytoplasm of macrophages and, occasionally, within neoplastic cells. A diagnosis of transmissible venereal tumor and concurrent leishmaniosis was made. Treatment with vincristine and allopurinol resulted in complete resolution of clinical signs and disappearance of the masses. The presence of amastigotes in neoplastic TVT cells may suggest an alternative mode of transmission of canine leishmaniosis where these diseases co-exist.     

Bilateral sinus cysts in a filly treated by endoscopic sinus surgery

Bilateral cysts in the frontal and caudal maxillary sinuses in a filly treated by endoscopic sinus surgery (sinoscopy) and triangulation technique are described. Sinoscopy has the advantage of being a minimally invasive technique and permits a complete inspection of the frontal and maxillary sinuses, which is not possible through flap sinusotomy.     

Bilateral mandibular dentigerous cysts in a dog

Cysts in the dental cavities of dogs are rare. This report documents the case of a young boxer that was referred after having had treatment for bilateral oral swellings. Dentigerous cysts were tentatively diagnosed. Surgery was performed to aspirate the fluid and remove the first premolars, which were positioned in the cysts. Histopathological examination of tissue collected during the surgical procedure confirmed the diagnosis.