Corneal dermoid is one of the many corneal diseases identified in the dog. Dermoids are superficial masses present from birth that contain many of the elements of normal hairy skin. They usually involve the cornea, conjunctiva, nictitating membrane (a membrane involved in winking of the eyelids), sclera and, less commonly, the eyelids. Although these masses are congenital, dogs and cats may not show clinical signs until long, coarse hairs extend from the surface and cause irritation. Congenital corneal dermoids are observed in newborn animals and may involve one or both eyes. The affected cornea appears to be covered over part of its surface with white, sometimes haired and usually pigmented skin. Hair follicles, sebaceous glands, and cysts lined with epithelium and filled with keratin and sweat glands are common. The corneal connective tissue may be thickened and lined with blood vessels but is otherwise unaffected.
Corneal dermoids are known to occur in the St. Bernard, German Shepherd Dog, Basset Hound, Dachshund, Welsh Corgi, and cats. Some puppies may have chronic epiphora and eye discharge. Surgical removal of dermoids is usually performed when the puppy is old enough for routine general anesthesia. After the surgery, the resulting ulcer is treated with broad-spectrum antibiotic and atropine ointment until the ulcer has healed. Surgery may lead to complete remission of signs and minimal scarring of the cornea. Although hair may be removed by manual epilation or electroepilation, it may regrow. If the dermoid is not totally removed, some degree of recurrence can be expected.
Corneal dermoids are known to occur in Welsh corgis
- Thomas Carlyle Jones, Ronald Duncan Hunt, Norville W. King. Veterinary Pathology
- Sheila M. Crispin. Notes on Veterinary Ophthalmology
- Lee JI, Kim MJ, Kim IH, Kim YB, Kim MC. Surgical correction of corneal dermoid in a dog
- Veterinary Surgery: Small Animal. Karen M. Tobias DVM MS DACVS, Spencer A. Johnston VMD DACVS