Chronic superficial keratitis (CSK), also known as pannus or Uberreiter's disease, is an inflammatory condition of the cornea in dogs, particularly seen in the German Shepherd. Both eyes are usually affected. The corneas gradually become pigmented and infiltrated by blood vessels, and the dog may eventually become blind.
CSK is usually a bilateral progressive condition, however the lesions are not symmetrical nor are they painful. Signs include pigmentation and vascularization of the cornea (extension of blood vessels onto the cornea). It is usually first seen at the lateral (temporal) limbus (the junction between the cornea and sclera), although it eventually can extend from any part of the limbus to cover the entire cornea. Severe cases can cause blindness. Although CSK is usually identifiable by the appearance of the eye and the breed of the affected dog, cytology will reveal the presence of lymphocytes and plasma cells. [1]
CSK is immune-mediated in nature, characterized by an infiltration of white blood cells into the superficial stroma of the cornea. These cells are predominantly CD4-expressing T lymphocytes and to a lesser extent CD8-expressing T cells. [2] The CD4-expressing T-cells secrete gamma interferon, which causes expression of the major histocompatibility complex class II molecules in the cells of the cornea. These class II molecules cause further inflammation by interacting with the T cells and triggering an immune response. [3] Ultraviolet light is important in the genesis of the disease which is seen at higher prevalence at elevated altitude [4] and has a seasonal variation with most cases occurring in the summer. There is likely also a genetic component to the cause of CSK due to its predominance in certain breeds.
Treatment of CSK is usually with topical corticosteroids or topical cyclosporine, but any treatment only controls and reduces the inflammation rather than providing a cure. [5] Other investigated treatments include pimecrolimus, a derivative of ascomycin that interferes with T cell activation and inhibits the production of inflammatory cytokines. [6] Strontium-90 radiation therapy is also used to treat CSK. [7] Canine sunglasses have also been used to help protect the eyes of dogs with CSK to prevent further damage from ultraviolet radiation. [8]
Chronic superficial keratitis is most commonly seen in German Shepherds, [9] but it is also found in Belgian Tervurens, Greyhounds, Siberian Huskies, Australian Shepherds, and Border Collies. [10]
Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired eyesight, photophobia, red eye and a 'gritty' sensation. Diagnosis of infectious keratitis is usually made clinically based on the signs and symptoms as well as eye examination, but corneal scrapings may be obtained and evaluated using microbiological culture or other testing to identify the causative pathogen.
Thygeson's superficial punctate keratopathy (TSPK) is a disease of the eyes. The causes of TSPK are not currently known, but details of the disease were first published in the Journal of the American Medical Association in 1950 by American ophthalmologist Phillips Thygeson (1903–2002), after whom it is named.
A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.
A mastocytoma or mast cell tumor is a type of round-cell tumor consisting of mast cells. It is found in humans and many animal species; it also can refer to an accumulation or nodule of mast cells that resembles a tumor.
The health of dogs is a well studied area in veterinary medicine.
Canid alphaherpesvirus 1 (CaHV-1), formerly Canine herpesvirus (CHV), is a virus of the family Herpesviridae which most importantly causes a fatal hemorrhagic disease in puppies less than two to three weeks old. It is known to exist in the United States, Canada, Australia, Japan, England and Germany. CHV was first recognized in the mid-1960s from a fatal disease in puppies.
Pythiosis is a rare and deadly tropical disease caused by the oomycete Pythium insidiosum. Long regarded as being caused by a fungus, the causative agent was not discovered until 1987. It occurs most commonly in horses, dogs, and humans, with isolated cases in other large mammals. The disease is contracted after exposure to stagnant fresh water such as swamps, ponds, lakes, and rice paddies. P. insidiosum is different from other members of the genus in that human and horse hair, skin, and decaying animal and plant tissue are chemoattractants for its zoospores. Additionally, it is the only member in the genus known to infect mammals, while other members are pathogenic to plants and are responsible for some well-known plant diseases.
Granulomatous meningoencephalitis (GME) is an inflammatory disease of the central nervous system (CNS) of dogs and, rarely, cats. It is a form of meningoencephalitis. GME is likely second only to encephalitis caused by canine distemper virus as the most common cause of inflammatory disease of the canine CNS. The disease is more common in female dogs of young and middle age. It has a rapid onset. The lesions of GME exist mainly in the white matter of the cerebrum, brainstem, cerebellum, and spinal cord. The cause is only known to be noninfectious and is considered at this time to be idiopathic. Because lesions resemble those seen in allergic meningoencephalitis, GME is thought to have an immune-mediated cause, but it is also thought that the disease may be based on an abnormal response to an infectious agent. One study searched for viral DNA from canine herpesvirus, canine adenovirus, and canine parvovirus in brain tissue from dogs with GME, necrotizing meningoencephalitis, and necrotizing leukoencephalitis, but failed to find any.
A corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. It is very common in dogs and is sometimes seen in cats. In veterinary medicine, the term corneal ulcer is a generic name for any condition involving the loss of the outer layer of the cornea, and as such is used to describe conditions with both inflammatory and traumatic causes.
Sudden acquired retinal degeneration syndrome (SARDS) is a disease in dogs causing sudden blindness. It can occur in any breed, but female dogs may be predisposed. Approximately 4000 cases are seen in the United States annually.
Discoid lupus erythematosus (DLE) is an uncommon autoimmune disease of the basal cell layer of the skin. It occurs in humans and cats, more frequently occurring in dogs. It was first described in dogs by Griffin and colleagues in 1979. DLE is one form of cutaneous lupus erythematosus (CLE). DLE occurs in dogs in two forms: a classical facial predominant form or generalized with other areas of the body affected. Other non-discoid variants of CLE include vesicular CLE, exfoliative CLE and mucocutaneous CLE. It does not progress to systemic lupus erythematosus (SLE) in dogs. SLE can also have skin symptoms, but it appears that the two are either separate diseases. DLE in dogs differs from SLE in humans in that plasma cells predominate histologically instead of T lymphocytes. Because worsening of symptoms occurs with increased ultraviolet light exposure, sun exposure most likely plays a role in DLE, although certain breeds (see below) are predisposed. After pemphigus foliaceus, DLE is the second most common autoimmune skin disease in dogs.
An anal sac adenocarcinoma is an uncommon and aggressive malignant tumor found in dogs that arises from the apocrine glandular tissue of anal sac. The disease exists in cats as well, but is much less common in that species. They are the second most common cancerous cause of hypercalcaemia in dogs, following T-cell lymphoma.
Vernal keratoconjunctivitis is a recurrent, bilateral, and self-limiting type of conjunctivitis having a periodic seasonal incidence.
Corneal neovascularization (CNV) is the in-growth of new blood vessels from the pericorneal plexus into avascular corneal tissue as a result of oxygen deprivation. Maintaining avascularity of the corneal stroma is an important aspect of healthy corneal physiology as it is required for corneal transparency and optimal vision. A decrease in corneal transparency causes visual acuity deterioration. Corneal tissue is avascular in nature and the presence of vascularization, which can be deep or superficial, is always pathologically related.
Corneal ulcer, also called keratitis, is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury.
Corneal dystrophies are a group of diseases that affect the cornea in dogs.
Herpetic simplex keratitis is a form of keratitis caused by recurrent herpes simplex virus (HSV) infection in the cornea.
Neurotrophic keratitis (NK) is a degenerative disease of the cornea caused by damage of the trigeminal nerve, which results in impairment of corneal sensitivity, spontaneous corneal epithelium breakdown, poor corneal healing and development of corneal ulceration, melting and perforation. This is because, in addition to the primary sensory role, the nerve also plays a role maintaining the integrity of the cornea by supplying it with trophic factors and regulating tissue metabolism.
Feline corneal sequestrum is the development of dark areas of dead tissue in the cornea of domestic cats. This disease is painful to the cat, although it develops slowly over a longer period of time. Cats will usually demonstrate teary eye(s), squinting or closing of the eye(s), and covering of the third eyelid.