76 OPHTHALMOLOGY FOR VETERINARIANS 



Membranous Conjunctivitis. — This occurs in both 

 man and beast. Fowls are particularly susceptible to it. 

 It not only attacks the eye of the fowl, but also the 

 mucous tract of the nose, mouth, and throat. This 

 condition in the fowl is known by the common name of 

 ''roup," and is allied to diphtheria in the human family. 

 The membrane is grayish- white, and in some cases is of 

 a thick, yellowish, cream color. It is usually thick and 

 tough, strongly adherent, invades the deep structures, 

 and extends to the sinus about the orbit. The fowl is 

 Kstless, often standing with its head drooped and un- 

 conscious of its surroundings. When the general sys- 

 tem becomes invaded with the toxemia, the fowl refuses 

 to eat or drink and much loss of weight takes place. If 

 the eyeball becomes involved, as it often does, the loss 

 of the organ follows. The membrane is so profuse as to 

 protrude between the lids, and in one case the writer 

 saw it perforated the upper lid, producing a large cica- 

 trix after healing. It is said to attack choice varieties 

 of fowls particularly. 



Cats, calves, and sheep are susceptible to diphtheritic 

 infection. There are forms of bacteria resembling so 

 closely the true Klebs-Lofifler bacillus it is with difficulty, 

 and only by certain biologic tests or characteristics, 

 they can be differentiated. In 1884 Lofifler described 

 two special types in animals — the Bacillus diphtheriae 

 columbrarum and the Bacillus diphtheriae vitulorum. 

 The former he obtained from the pseudomembranes 



