IJIHEASES OF DOMESTIC ANIMALS. 63 



formation of a film over the eye. In say twenty-four hours, if the irrita- 

 tion has been removed, this will often be absorbed without anything 

 being done, but there are many remedies recommended for getting 

 rid of this. Bathe with cold water, and stimulate with iodide oi 

 potassium and nitrate of silver, not too strong, but just gently. in 

 case the exudation is broken up to a certain extent, and there is a ten- 

 dency to abrasion of the cornea, stimulate every day or two, and keep 

 this up for some time ; this may come from conjunctivitis in a very 

 mild form. When the film first shows itself, the owner is much alarmed. 

 Iodide of potassium is used, five grains to an ounce of water, and it 

 may be necessary to give diuretic or purgative medicines. Belladonna 

 may be given internally and applied round the eye, but it is generally 

 best to place directly on the eye. Treatment for the dog is tonics, 

 good feed, and, stimulate the eye with the remedies given. One or two 

 applications will generally suffice. If you have a case of conjunctivitis 

 that has come on very slowly, examine such a case very closely. 

 There may be ulcerated spots. The remedies given increase the irrita- 

 tion for some time, but this will soon be relieved. Eyes are sometimes 

 injured by severe caustics, pounded glass, alum, etc. In conjunctivitis 

 you wil^ find benefit from bleeding in the angular vein, and if 

 it does no good, it will do no harm. In an acute attack the animal 

 should be sparingly fed for a few days. There is no better remedy than 

 belladonna. It may be necessary to scarify the eyehd in some cases. If 

 it has received a severe injury, then apply fomentations. 



Periodic Optlialuiia. — So called because it occurs periodically. It is 

 not very uncommon in this country, and it differs from simple ophthal- 

 mia by the internal structure being first effected, coming from something 

 in the constitution. It is a constitutional affection, operating on the 

 organ of vision, first attacking the internal structure, then involving the 

 whole of the anterior part of the eye, and sooner or later terminatirjg in 

 partial or complete loss of vision. Many other definitions might be 

 given. Constitutional ophthalmia, due to something in the system. 

 Hereditary, due to some hereditary influence. Odontalgic, supposed to 

 come from something the matter with the teeth. According to some 

 authorities, wolf teeth affect the eyes. But I think they do not in any 

 way affect the eyes. The fifth pair of the nerves supplies common sensa- 

 tion to the eyes and teeth, and wolf teeth irritating this, affect the eye. 

 But this is not held by veterinarians as a general thing. Another form 

 is gouty ophthalmia, due to something in the system similar to gout, and 

 acting upon the eye. This disease has been long known and great 

 attention paid to it. Other names, moon-blindness, lunatic ophthalmia, 

 supposed to be influenced by the moon. It was supposed that they 

 could see readily at some periods of the moon, while at others they could 

 not. I think it is more common here than in Britain, perhaps owing to 

 the extremes of heat and cold. But there are other causes which operate 

 in causing it, and it receives various names, arising from the various 

 symptoms produced. Pathology is not very well known at present ; 

 perhaps a great many cases are due to hereditary influence. It was once 

 considered the bane of horse flesh. Breeding from sound horses has 

 done more to eradicate it than anything else. '' Like begets like." 



Causes. — Certain excitants, extremes of heat and cold, are prominent 

 causes ; dark and ill-ventilated stables ; working and neglecting the 

 horse, but in most cases there exists an hereditary predisposition. I do 

 not say in all ; there may be exceptions. Lexington, a well-known horse, 

 suffered from periodic ophthalmia, supposed to be the result of hard 

 work, and his progeny is affected to a considerable extent. It may not 



