This is the name given to a collection of serum in the cavity of the peritonaeum.

Ascites, which is more frequently met with in dogs than in any of the other domestic animals, occurs in two forms - idiopathic or active, and symptomatic or passive.

1. Idiopathic ascites generally attacks young and strong dogs, and is caused by exposure to cold and damp. Sudden changes of the weather, damp kennels, drinking or jumping into cold water when the body is heated by active exercise, exposure to wet and cold after having been confined in a warm place, are amongst the means by which active ascites is induced. In such a case the symptoms come on suddenly, and the effusion is poured forth rapidly; there is no pain of the abdomen, but some febrile excitement; and the effusion is not so much an inflammatory product as the result of a loss of balance between the processes of exhalation and absorption, whereby the fluid of the blood, under the application of cold to the skin, exudes into the peritonseal cavity, instead of being excreted and discharged by the natural channels. Anasarca, or dropsy of the areolar tissue, may co-exist. Another form of ascites, which is of a truly inflammatory character, is that which is the sequel of acute, or of chronic peritonitis.

2. Symptomatic ascites is rather a symptom than a substantive disease. In the dog, chronic disease of the liver, the spleen, the kidneys, etc., not unfre-quentiy leads to ascites. This is especially the case when the liver is either contracted or enlarged, particularly the former. The flow of blood through the vena porte is then retarded; the tributaries of that vein become distended and relieve themselves of a part of their fluid contents, which collects in the peritonaeal cavity. The same effects are produced by the pressure of tumours on the trunk of the vena portae.

Ascites very frequently follows asthma, and the repercussion of mange and eczema.

Symptoms

The most obvious symptom of ascites is of course the enlargement of the abdomen. The precursory symptoms necessarily vary with the cause which has produced the accumulation of serum. There is probably a history of asthma, or chronic cough, or skin disease, or ravenous appetite with progressive wasting. Or the appetite has been observed to be wanting, the dog has lost his usual playfulness, appears dull and languid, passes little water, has confined bowels, and probably the hind legs are somewhat swollen. The enlargement is observed after a variable period; or it may come on in a few hours after a previously healthy dog has been exposed to cold and damp. On directing attention to the abdomen, which may or may not be slightly tender to the touch, important morbid conditions are discovered. The belly may be slightly or enormously enlarged; and as this enlargement may be mistaken for pregnancy, obesity, or tumours, it is necessary to be careful in pronouncing one's diagnosis. The presence of fluid in the abdomen is indicated by fluctuation, that is, when the open flat hand is placed against one side of the belly, and a slight tap is made with the fingers of the other hand on the opposite side, a sensation is felt which is caused by the movement of fluid. This sign of ascites is most marked when the accumulation is considerable; but even a small quantity can be detected by the experienced hand. Again, when the palm or surface of the left hand is placed flat on the abdomen of the dog, and the dorsal surface of one finger struck with the tips of the right hand fingers - when the abdomen is thus percussed - valuable information is obtained. In whatever position the dog may be placed, a clear sound is elicited at the upper part of the abdomen, and a dull sound at the lower part, because the bowels float above the liquid which always gravitates nethermost. As the effusion increases, the breathing becomes quicker and more laboured, and is accelerated on the least exertion. If this be allowed to go on, the lungs have no room to play in, because the swelling encroaches on the capacity of the chest, and the dog dies suffocated. Dropsy of the cellular tissue of the legs and skin of the belly and chest frequently precedes, and almost always accompanies, internal dropsy. In addition to these symptoms, the pulse is weak, the appetite bad, the thirst great, the secretion of urine diminished, the bowels confined, and the strength reduced.

The following account is taken from the "Veterinary Record," vol. v. page 23: - A Newfoundland dog had been costive, dull, and off his appetite for several days. The veterinary surgeon who attended the case found the dog dull-looking, and unable to void faeces from their being hard. He noticed that the body appeared full and tympanic, but he felt no fluctuation, and therefore ascribed the enlargement to distention of the intestines from impacted faeces. Purgatives and enemata were accordingly used, but with only slight benefit. Some days afterwards the symptoms became more severe, and still the same open-the-bowels treatment was resorted to. The dog died. There was half a pailful of serum in the belly, neither food nor excrement in the bowels, and the liver was enlarged and softened. The heart was wasted, and its structure soft and flabby; the cavity of the pericardium contained two quarts (?) of a coffee-coloured fluid, and the serous surface of the pericardium was studded with fibrinous deposits.

Of course, the veterinary surgeon made a mistake in this case, and he was not ashamed to avow it in a public journal. Humanum est errare. The enlargement, which he attributed to a collection of hardened excrement in the bowels, was really due to enlargement of the liver, and copious serous effusion into the abdominal cavitv. Per-cussion over the abdomen would have detected the dulness of the liver exceeding its healthy limits; and holding the palm of the left hand on the left side of the dog's belly, at the same time striking the right side with the tips of the right fingers would have detected fluctuation - the movement of fluid. When the bowels are filled with faeces, the sound on percussion is of course dull, and gives the idea of solidity underneath the fingers; whereas when there is simply effusion, the sound is not of necessity dull, the uppermost part of the belly giving the clearest note.

Although the treatment was based on a wrong diagnosis, still the case was evidently far advanced, and the patient would have died in spite of the best-directed means.

Blaine says, "Dropsy of the belly may be distinguished from fat by the particular tumour that the belly forms, which, in dropsy, hangs pendulous, while, at the same time, the backbone sticks up, and the hips appear prominent through the skin: the hair also stares, and the feel of the coat is peculiarly harsh. It may be distinguished from pregnancy by the state of the teats, which always enlarge as gestation advances; nor has the impregnated belly, however full, that light tense feel, nor the shining appearance, which are observed in dropsy: there may be also foetal inequalities distinguished in it; and when pregnancy is at all advanced, the young may be felt to move. The most unequivocal mode, however, of detecting the presence of water is by the touch. If the right hand be laid on one side of the belly, and the other side is gently struck with the left, an undulating movement will be perceived, exactly similar to what would be felt by placing one hand on a bladder of water, and striking it with the other.

Treatment

Ascites unconnected with organic disease is generally curable; but when dependent on diseases of the liver, spleen, heart, etc., it generally ends fatally.

The medicines most likely to be of service are the following: -

Aconitum,* when the ascites is of the active kind, with some febrile disturbance and tenderness of the abdomen.

* For the doses, etc., refer to the " Introductory Remarks."

The removal of the fluid, by the operation of tapping, is imperatively called for when the breathing is much obstructed. The trocar should be pushed through the abdominal wall, in the middle line, midway between the navel and the pubis; and all the fluid allowed to escape through the canula. The belly should be bandaged for several days to give mechanical support to the weakened part, and so far to lessen the chances of re-collection. There is always some amount of danger in connexion with tapping. When the serum is thick, brown, and foetid, an unfavourable result may be apprehended. Tapping is of least service when the dropsy depends on organic visceral disease; and of most service when the mere pressure of the fluid prevents the due absorbent action by which the accumulation might be otherwise removed. In all cases it must be looked upon rather as a temporary expedient than as a curative means. It may be necessary to tap more than once; and in some instances it will be observed that with each tapping the fluid accumulates again more and more rapidly.