A pale fatty looking elevation on the sclerotic at the inner side of the cornea is not unknown in the dog, resembling pinquecula of man. It has not been seen to prove harmful and may be safely ignored.
Lipoma has also been observed (Müller) and when troublesome may be removed by excision with scissors.
Melanosis is met with in gray horses in connection with the same disease of the skin of the lids, and usually with generalized pigment tumors. In the latter case surgical interference is useless unless it is to secure a very temporary relief.
Dermoid Tumor of the Conjunctiva. This consists in a cutaneous product, consisting externally of a mass of epidermic cells, beneath which are connective tissue, fat cells, and muscular fibres, glands and growing hairs. It usually extends inward from the outer portion of the sclerotic conjunctiva and may encroach on that of the cornea. It is firmly adherent to the sclera, and sometimes to the cornea by its base and deeper aspect, but the apex is free and more or less projecting. The color is yellow, or more or less blackened by pigment or even reddened by blood. It has been observed, above all, in dogs, Prince reports a case in a calf and Zundel in a sheep. The Cornell Veterinary College clinic has furnished cases in ox and dog. They have, however, nearly always been seen in young animals and are probably congenital.
These are easily removed from the eye anæsthetized by a 4 per cent. solution of chloride of cocaine. The inner projecting end of the tumor is seized by rat-tooth forceps, and carefully snipped off with sharp scissors curved on the flat. Where adherent to the cornea it must be carefully handled, but where attached to the thicker and more resistant sclerotic it can be dealt with more freely. A pencil of silver nitrate may be used to check the bleeding, or that may be effected by cold water freely applied.
Polypus, a small, pale, pediculated tumor of the conjunctiva is described by Lafosse and should be removed by scissors, and bleeding checked by cold, wet applications.
PTERYGIUM.
This name is employed to designate a triangular conjunctival fold broader at its sclerotic end and gradually narrowing to its corneal extremity, with loose, slightly overlapping borders, and firmly fixed to the structures beneath. It is more vascular than the surrounding conjunctiva, and its comparatively large blood-vessels have suggested the veins of an insect’s wing—hence its name. The growth may extend from either canthus toward or partly over, the cornea.
Möller and Leclainche claim its existence in dogs, though rarely to such an extent as to demand surgical interference. Dunewald operated on a case in the cow.
Unless growing, it need not be interfered with. It may be dissected up with scissors the narrow end being dragged on by forceps. Another method is to cauterize the narrow end with the electric cautery which leads to material contraction of the entire mass.