INFLAMMATION OF THE CONJUNCTIVA. 355 



ing to Frohner, 40 per cent, of all dogs are affected more or less 

 by conjunctivitis follicularis. 



Etiology. Catarrh of the eyes may occur at any period of the 

 animal's life, and, as a rule, affects both eyes ; in very rare in- 

 stances only one. It is generally the result of exposure to cold or 

 the influence of sharp, cold winds. It is, therefore, apparent why 

 it appears at certain seasons of the year more than at others — that 

 is, in the spring and fall. Mechanical and chemical influences 

 also produce a certain effect, such as foreign bodies (dust, hair, 

 etc.), eyelashes turned in, smoke of soft coal, etc. 



Catarrh of the conjunctiva is intimately connected with catarrh 

 of the respiratory organs, especially cold in the head, distemper, 

 and all serious internal diseases which have a prolonged course. 



Purulent Ophthalmia (Purulent Conjunctivitis; Blennor- 

 rhcea). This form of conjunctivitis is marked by considerable 

 swelling of the membrane. This is sometimes spotted red by 

 hemorrhages, sensitiveness to light, and photophobia, the animal 

 constantly winking or convulsively closing the eye. The secretion 

 of the eye is changed into a muco-purulent mass, becoming filled 

 with a thick, yellowish-green fluid with pus, and in this condition 

 complications of the cornea are generally present. The latter be- 

 comes dull in the centre, showing erosions in some cases. This 

 opacity of the cornea gradually increases, becoming darker, more 

 opaque, and then taking a yellowish-gray coloration. We may 

 see in some cases ulceration of the cornea. 



This blennorrhcea of the conjunctiva is a rare and dangerous 

 disease, causing extensive inflammation and ulceration of the cor- 

 nea, the condition being prolonged in some cases from four to eight 

 weeks, and in extremely bad cases the eye is lost. 



Etiology. It is admitted that this disease is due to a specific 

 infectious substance iu the course of some epizootic disease. This 

 may or, may not be present. It is possible to produce the same 

 form of the affection by inoculatiog the conjunctiva of a healthy 

 dog with this purulent material. Guilmot observed that by placing 

 dogs in a kennel which had been previously used by a dog affected 

 with this disease that they soon became similarly affected. In many 

 cases we see no ulceration, simply the development of the conjunc- 

 tivitis. Frohner states that he has observed purulent conjunc- 

 tivitis, which he found to be due to the transmission of gonorrhoeal 



