DISEASES OF- THE EYE AND ITS APPENDAGES. 361 



rheumatic inflammation of tlie optic nerve, or from extension of deep 

 inflammation of the eye involving the retina. It sometimes ocelli's as 

 the result of excessive loss of blood or of great debility. 



Symptoms. — In this disease seldom any observation is made until 

 the animal in its gait and by its action indicates blindness. Gener- 

 ally both eyes are affected. The eyeball remains clear, and the pupil 

 permanently dilated. No response to light is manifested. 



Treatment. — If due to debility, loss of blood, or associated with 

 rheumatism, general blood tonics may be given in tlie feed, namely, 

 powdei-ed sulphate of iron, 1 dram; gentian, 2 drams; nux vomica, 

 one-half dram; to be given twice a day. In cases of rheumatism, 

 one-half ounce of saltpeter may be added. 



FILARIA OCTILI (wORM IN THE EYe). 



Filar^la oculi (provisionally taken as the larva of F. eervina). — 

 This is a small white wonn, and is found in the eye, swimming in the 

 aqueous fluid in the anterior chamber. It may be apparently harm- 

 less for a long time, but will eventually induce keratitis with inflam- 

 matory exudations. 



Treatment. — The cornea may be punctured at its upper and outer 

 margin, and the worm squeezed out with the aqueous humor. The 

 latter will be formed again. This operation will result disastrously 

 unless the greatast care and skill are employed. 



CORNEAL DERMATOMA ( HAIRY TUMOR ON THE EYEBALL) . 



In a few instancas this has been seen as a congenital growth. The 

 tumor arises from the cornea or the sclerotic, covered by its respective 

 membrane, with a gi'owth of hair upon its surface. These tumoi"S 

 may be quite prominent or flattened, and are dark in color: the hair 

 may protnide between the eyelids, giving the animal the appearance 

 of having a double eyelid. 



Treatment. — A surgical operation becomes necessary for their re- 

 moval — one requiring a skilled operator. 



STRABISMUS (sQUINTING). 



This is a very rare affection among cattle. Strabismus may be 

 either single or double — affecting one eye or both. It is due to a 

 paralysis, or a weakening of one of the straight muscles of the eye- 

 ball. Generally it is a congenital defect, and the squinting is toward 

 the nose — strabismus convergens. It is best not to attempt to i-emedy 

 the defect, as the risk in an operation is gieater than the chances of 

 success warrant. 



