112 OPHTHALMOLOGY FOR VETERINARL\NS 



inflammation of the iris, foreign bodies on or in the cor- 

 nea, and certain drugs known as myotics. 



W. B. Coakley^ has noted pin-point contraction of the 

 pupil as a pathognomonic eye-symptom in rabies. 

 ^'The contraction is so strong as to resist the effect of 

 mydriatics." He further says, "A contracted pupil 

 which yields to mydriatics is sufficient to exclude 

 hydrophobia. There is medium dilation immediately 

 before death." In the same article he notes that ''alco- 

 hol, opium, morphin, codein, carbohc acid, eserin, and 

 chloral, all of which contract the human pupil, were 

 given to dogs in lethal doses without producing the 

 myosis noted in rabbits." 



• Iritis, or inflammation of the iris. The iris is practically 

 an extension of the anterior portion of the ciHary body, 

 and we will consider them together. The relation of the 

 blood-vessels and their source must be kept in mind, 

 as those of the chorioid cihary body and iris are inti- 

 mately associated, and a knowledge of their arrangement 

 is necessary when we come to consider inflammation of 

 these structures, as it is rather exceptional for the iris 

 to be inflamed when the ciliary body is not more or less 

 involved. 



An iritis may be mild or severe in type. The iris be- 

 comes hyperemic, the blood-vessels dilated, and a 

 change of color from that of the other iris takes place, 

 according to the amount of inflammation present. 



^ Medical Record, July 6, 1907. 



