On examining dogs that have died of that form of distemper which invades the respiratory mucous membrane in particular, and which usually presents the foregoing symptoms, we find, in the earlier stage, when a convulsion has carried off the patient, the mucous membrane of the nose and of the pharynx in a congested state. When the disease has lasted for a longer period, the membrane lining the frontal and ethmoidal cells, as well as the nose, is found to bear all the appearance of high inflammatory action, and the cells are more or less filled with pus. The nasal membrane is also sometimes found ulcerated, and even the septum eaten through: hence the fetid discharge and haemorrhage sometimes met with. This ulceration may also be found in the pharynx, larynx, and bronchial tubes. The mucous membrane of the air-tubes is fully injected, and the tubes contain abundant muco-puru-lent secretion. When pneumonia has existed, we find circumscribed congestion, and the signs of lobular hepatization, and of suppuration. Pleuritic adhesions and serous effusions are less common.

In some cases, the chief force of the disease falls on the digestive mucous membrane. This complication is most apt to come on in distemper during the second period of teething, or when the dog has been fed too freely, or on improper food. Nothing, however, is so sure to encourage the tendency to diarrhoea and dysentery, and even to excite them, as purgatives, and especially calomel. The derangement may consist simply in the passage of liquid stools, or of imperfecly digested food; but this is very prone to run on to dysentery. The appetite is usually ravenous and vitiated, and there may or may not be vomiting. After inaction of the bowels and some indications of colicky suffering, diarrhoea begins. The dog's back is arched, his abdomen tender to the touch, and he looks round every now and then to the seat of pain. He gives utterance to sharp, short cries. The intestinal discharge is liquid, dark coloured, and chiefly consists of mucus mixed with more or less blood; in some cases pure blood is passed. There is strong straining in the act of passing this discharge. Subsequently, the breath becomes most offensive; ulcerations appear on the gums, palate, tongue, pharynx, and an offensive discharge flows from the mouth. All these symptoms increase in severity, the vital powers become profoundly prostrated, and death from exhaustion or convulsions soon ensues.

These symptoms of intestinal disease are generally preceded by the cessation of the discharges which characterize the primary disease; and they sometimes complicate the termination of the typical form of distemper.

The post-mortem appearances are: Enlargement of the mesenteric glands; entire extent of intestinal mucous membrane more or less injected, contracted in calibre, thickened, and lined by adherent lymph; small ulcers, surrounded by an inflammatory circle, situated near the orifices of the glands of the small intestines.

The disease known as "Yellow Distemper" is by some regarded as a local complication of ordinary distemper; by others, as a distinct disease. The discharge from the nose is usually so scanty as to escape cursory observation. There is a char-acteristic yellow line of the skin, mouth, and eyes; the faeces are yellowish and decidedly offensive; the bowels obstinately confined; the urine high coloured and scanty. The disease makes rapid progress; the animal will neither eat nor move; and in about three days death takes place in the majority of cases, unless the treatment be prompt. On examination after death, the yellow colour is found to pervade all the organs, the liver is congested, and the gall-bladder filled with thickened and dark bile.

In some cases a pustular eruption breaks out on the surface of the chest and belly, inside of the thighs, etc. The pustules break, and scabs form from the pus concreting. Writers differ widely in their views on the nature of this complication; it is a subject that requires further investigation. The breaking out of such an eruption is on the whole favourable. Is not that form of distemper, in which there is a pustular eruption, identical with, or analogous to, smallpox?

The nervous system is severely deranged in a large proportion of distemper cases.

Encephalitis, or inflammation of the brain and its membranes, begins differently in different cases. In some, this complication of distemper sets in by a paroxysm of general convulsions - "a distemper fit" - which may prove fatal at a comparatively early stage of the general disease, or which may be succeeded by other similar attacks that carry off the animal. In other cases, encephalitis is preceded by the discharge from the nose diminishing or ceasing, or by an existing diarrhoea abating; and also by a peculiar bright and sparkling appearance of the eye. In a third class of cases, stupor is the first indication of head disease. It is most prone to come on when distemper attacks dogs whilst teething.

The head is hot; the carotid arteries throb violently; the eyes are injected and brilliant; the pupil contracted; the dog emerges from a spiritless state into one of vivacity; the appetite recently absent is now voracious, and also depraved, for the animal eats immoderately, and even gnaws at wood and other indigestible bodies. Then the jaws are champed, frothy saliva flows from the mouth, twitch-ings appear about the face, eyelids, and other parts; unconsciousness steals over the animal, and he appears to be blind, for he stumbles against every obstacle in his way. Sometimes symptoms of maniacal violence come on; the dog bites himself and every object near him, tears up the ground, etc. These symptoms subside and return after uncertain intervals, and generally terminate in convulsions. Suddenly, the eyes glare and turn in their sockets, and the dog falls down violently convulsed; its body and limbs spasmed, rigid, and variously distorted; consciousness suspended; the secretions passed involuntarily, etc. These movements gradually abate, the senses return, and the animal probably starts off in a fright, as if he were "mad." These fits vary in frequency, duration, and severity. Death may take place under the first attack, or not until after several violent seizures. The appearance of an eruption at the beginning of these attacks is a favourable event. In some cases, the unconscious animal turns his head to one side, and constantly walks round and round in a circle; the pupil of the opposite side is widely dilated, and general paralysis supervenes. Paralysis of the hind legs and chorea are occasional sequelae of this disease of the brain.