While diphtheria is an affection which very rarely attacks dogs, the fact that it has been observed among them renders a brief description warrantable.

It is a disease which invades especially the membrane of the air passages, and general infection follows the local expression. The local disease appears as an inflammation of the mucous membrane, especially of the mouth, pharynx, nose, larynx, and deeper air passages, and precedes the formation of a greyish-white membranous exudation.

The constitutional affection has the character of infectious diseases, and is essentially the same as in all dependent upon blood poisoning. The problem is still unsolved whether diphtheria is at first a general disease, and poisoning of the blood and the local affections of the mucous membrane are secondary manifestations, or whether the disease begins by local infection, from which point the poison is taken into the system and the whole organization becomes contaminated.

It is generally accepted that the germ of the disease first fixes itself upon a certain part of the body, more often the mucous membrane, and there at its point of attachment it excites a local affection, then through absorption the poison penetrates the tissues and is soon carried throughout the whole body.

Diphtheria is an epidemic disease, and like all others has an especial cause, a contagious virus or infectious miasm. Certain conditions favor the propagation of the disease; impure air and poisonous exhalations from decomposing filth are important factors in its production. Among the reported cases of the disease among dogs, it is observed that the onset in some was marked by great febrile disturbance; in others the constitutional symptoms were less severe. In the larger proportion the disease attacked the mucous membrane of the throat, and more rarely were the • nasal passages first involved. In the former the throat presented a dark red, swollen, glistening appearance; the glands of the neck being enlarged and tender, and swallowing difficult. In some instances ulcers were seen on the tonsils.

When the disease assumed a concealed or nasal form, it manifested itself by general depression, fever of a low type, and a thin, reddish, offensive discharge from the nose. The glands of the neck were swollen in these aa in the other cases. Where the disease has appeared it has gen-erally proved fatal. When recovery took place, in some loss of sight, in others paralysis and chorea followed.

Cases are on record where diphtheria has been without doubt transmitted from man to dogs; this fact, strongly evincing that the disease is analogous in both, is important in considering treatment.

If the deeper air passages become involved as shown by harsh, croupy, spasmodic breathing, the case may be considered hopeless. If the disease takes on the concealed or nasal typo the nose must be frequently syringed with lime water or carbolic acid solution; two grains to an ounce of water. An application of dry powdered sulphur, blown into the throat through a tube or by means of a small bellows, is advised. This operation should be performed every half hour if possible. For internal treatment referable to the congestion of the mucous membrane, chlorate of potassa should be given. An ounce may be added to a pint of water, and of this solution two or three teaspoonfuls can be given every hour. Beef tea, raw eggs, milk, and brandy should be forced into the animal at frequent intervals, to sustain the vital powers.