CONJUNCTIVITIS 515 



the conjunctiva and its submucous tissue. It occurs in all 

 small animals, most frequently in birds. 



Etiology. There are many factors producing parenchy- 

 matous conjunctivitis. Many of them are the same as those 

 causing the catarrhal form. Injuries to the mucous mem- 

 branes and underlying structures can produce it. Chronic 

 agents in the form of irritants, such as irritating collyria, 

 when used too often or in too large quantities; thermic agents 

 in the form of hot water or hot antiseptic solutions. The 

 disease is observed in hunting dogs from exposure, or to 

 foreign bodies getting into the eyes while going through 

 briers and brush. Infection plays an important role in the 

 production of this form of conjunctivitis. The infection is 

 often introduced directly into the conjunctiva! sac where it 

 enters small wounds and produces intense inflammation of 

 the parenchyma. Numerous organisms have been isolated 

 in these cases. It is evident that no one specific organism 

 produces it. The disease may also develop secondarily 

 (hematogenously) to some of the infectious diseases. It is a 

 common sequel to dog distemper or epitheliosis of fowls. 



Symptoms. -The early indications of the disease are 

 swelling and puffiness of the mucous membrane. This is so 

 marked in many cases that the swollen conjunctiva pouches 

 outward over the palpebral borders or the cornea. During 

 this stage the conjunctiva is intensely congested and 

 reddened. There is considerable lacrimation and photo- 

 phobia during the entire period of the disease. In the second 

 stage there is a purulent discharge from the eye, which may 

 be very copious. The general condition of the patient is 

 usually not disturbed unless complications develop, or from 

 the attending infectious diseases. 



Prognosis. The prognosis in most primary cases is favor- 

 able. In the acute form it subsides in a week or ten days. 

 When secondary to infectious diseases, the prognosis is not 

 so favorable. In such instances it may develop into a chronic 

 purulent conjunctivitis. 



Treatment. - -Prompt treatment is important in preventing 

 the spread of the inflammation. Antiseptic and astringent 

 solutions should be employed: Boric acid (2 per cent.); 



