Tag Archives: Siberian Husky

The Cornea

Congenital Abnormalities Comeal Opacities. The cornea of the newborn puppy or kitten is a light blue color; or at least the cornea is less clear than that of the adult. In 2 to 4 weeks, corneal clearing is sufficient to permit ophthalmoscopic examination. It is not unusual to observe multifocal or diffuse faint white opacities in the corneas of young puppies and kittens. The opacities represent superficial foci of edema, and most are self-limiting. The cause of these opacities is unknown. Therapy is not necessary unless the opacities are accompanied by a mucopurulent discharge, in which case topical ophthalmic antimicrobial preparations may be applied. Animals born with their eyelids open often have diffuse corneal edema that clears in 14 to 18 days. Because reflex lacrimation is absent at birth, the exposed cornea is subject to desiccation and infection and can be avoided by frequent application of a broad-spectrum antimicrobial ointment every 3 or 4 hours until the animal is 10 to 12 days old. Cats with lysosomal storage diseases may develop corneal opacities related to the accumulation of polysaccharides within the endothelial cells and fibroblasts of the cornea. Fine granular deposits in the corneal stroma may Read more […]

The Anterior Uvea

The irides of the puppy and kitten are often a different color than those of the adult. The blue-gray iris of puppies and kittens usually changes to the adult coloration within a few weeks. Iris color is ultimately related to the degree of stromal pigmentation and is influenced by coat color. Congenital Abnormalities Persistent Pupillary Membranes. Persistent pupillary membranes are strands of tissue that arise from the anterior iris surface and represent remnants of an embryonic vascular system. The persistent pupillary membranes may be confined to the iris surface or may extend from the iris to the cornea or lens (). Persistent pupillary membranes are inherited in the basenji. Iris Cysts. Iris cysts are floating, fluid-filled vesicles that arise from the posterior iris epithelium and are usually found in the anterior chamber. Iris cysts may be unilateral or bilateral and singular or multiple in number. Pupillary Abnormalities. A notch-like defect (coloboma) is occasionally seen in the ventronasal pupillary border of young dogs and cats, resulting in a keyhole-shaped pupil. An eccentric pupil (corectopia) may accompany multiple ocular defects, as occurs in the Australian shepherd. Eccentric pupils are usually Read more […]

The Lens and Vitreous

The lens develops rapidly in the early stages of embryogenesis, during which time it is nourished by the hyaloid vessel. The fully developed lens is avascular; by the second week of life, no remnants of the hyaloid system should remain. The normal lens often exhibits minor imperfections that can be easily detected with magnification in dogs and cats younger than 1 year. These include prominent anterior and posterior Y sutures and minute granules in its nucleus and cortex. A mosaic of brown pigment spots is occasionally seen on the anterior lens capsule near the center of the pupil, representing remnants of embryonic mesoderm. Disease of the vitreous would be expected to influence the lens or retina because of its attachments at the posterior lens surface and the optic disc. Congenital Abnormalities Congenital lens abnormalities include alterations in size or shape. Congenital absence of the lens (aphakia) is uncommon. In microphakia, the margin of the abnormally small lens along with elongated ciliary processes may be observed after pupillary dilation. Microphakia occurs along with other ocular defects in the Saint Bernard and beagle and in cats. Luxation of the microphakic lens may cause glaucoma. Lenticonus is a Read more […]

The Upper Airway: Nasal Cavity, Paranasal Sinus, Nasopharyngeal, Pharyngeal, and Laryngeal Diseases

Sneezing and nasal discharge are the most common clinical signs of nasal cavity disease. Owners of puppies or kittens that are quickly cleaned by their mother or that are fastidious about licking any appearing discharge may overlook a nasal discharge. Viral disease or environmental irritants usually cause a serous or mucoid discharge; bacterial disease causes a purulent or mucopurulent discharge. Sneezing is usually prominent in acute disease but wanes with chronicity. Acute viral diseases sometimes cause enough destruction of the nasal epithelium to obliterate the sneeze reflex, despite the presence of nasal discharge and other upper respiratory signs. Less common signs of nasal disease include stertorous breathing, pawing or rubbing at the nose or mouth, facial pain, facial deformity, ocular discharge, exophthalmos, or fetid breath. Because clinical signs related to the nose and sinuses can be manifestations of oral, pharyngeal, airway, and pulmonary disease, these areas should be carefully inspected. Evaluation of the nasal cavity should include oral and dental examination, radiographs of the nasal cavity, rhinoscopy, and visual examination of the nasopharynx and internal nares (). Pharyngeal and laryngeal disease Read more […]

Tetraparesis: Inflammatory diseases

Chronic inflammatory demyelinating polyneuropathy Clinical signs: Chronic inflammatory demyelinating polyneuropathy (CIDP) causes slowly progressive LMN tetraparesis in adult dogs and cats with no gender or breed bias (). Signs can relapse intermittently and can progress to tetraplegia. Shifting lameness, a plantigrade stance and ventroflexion of the neck have been described in cats, along with megaoesophagus and regurgitation. Leg tremors and laryngeal and facial paralysis have been noted in dogs. Pathogenesis: This is an apparently immune-mediated disease in which the inflammatory reaction is focused on peripheral nerve myelin sheathes. The aetiology of the disease is unknown but it appears to be similar to chronic inflammatory demyelinating polyneuropathy in humans. Diagnosis: Diagnosis is reached by a combination of electrophysiological studies and nerve biopsy. Typically, motor nerve conduction velocity is reduced. There is multifocal paranodal demyelination in teased nerve fibre preparations, and thinly myelinated fibres are visible on semithin sections. Electron microscopy reveals macrophages stripping myelin, and the presence of demyeiinated and remyelinated fibres. There is also a mononuclear infiltrate. Treatment Read more […]