Dropsy is an accumulation of watery fluid or serum, in one or more of the serous cavities of the body, or in the inter-spaces of the areolar tissue, or in both.

When the serum is effused into the areolar tissue of a part, that part is said to be (edematous, and the disorder is called oedema.

When the serum is collected in the serous cavity of the pleura, there is hydrothorax, or dropsy of the chest - a serious result of thoracic inflammation, and spoken of in its proper place.

Ascites, or dropsy of the belly, consists of an accumulation of serum in the peritonseal sac. This form of dropsy is also mentioned under its proper head.

* See Appendix.

† For the dose, etc., consult the "Introductory Remarks."

There are other local dropsies, bearing names indicative of the local lesion, such as dropsy of the head; of the ovary, etc. Anasarca is the term used in speaking of a collection of serum, more or less considerable, in the areolar tissue of the body generally.

Dr Tanner says, "To explain the mode in which dropsy may originate, it must be remembered that from all the surfaces of the healthy body, a kind of excretion or oozing forth of fluid is constantly taking place, accompanied at the same time by absorption; so that when the two processes of exhalation and absorption are properly balanced, the surfaces will merely be kept moist. But suppose that the balance from some cause is disturbed, imagine exhalation to take place more rapidly from the surfaces of one of the shut sacs, or absorption more slowly, than in health. Under such circumstances, it is clear that dropsy must result. It is probable that absorption takes place by the lymphatics, by the lacteals, and by the veins; the first removing the worn out particles of the body; the second taking up the chyle from the alimentary canal; while the third imbibe the fluid exhaled from serous membranes. In dropsy, the veins are generally in fault, and it often happens that from congestion these vessels are unable to take up more fluid. Hence, if the process of exhalation remains even as in health, an accumulation of fluid must take place."

In Anasarca, the areolar tissue under the skin is infiltrated with serum, and the body presents a swollen appearance without any redness of the skin itself. The swollen part, when pressed upon with the finger, yields, and this "pitting" continues for a short time and gradually disappears. The effusion varies in extent, and is generally confined to the legs and belly, - to the areolar tissue of these parts. The fluid, of course, gravitates towards the most depending parts. There is usually a certain amount of anasarca in ascites and hydrothorax; when the causes of these two last diseases continue long, general dropsy is the consequence. (Edema of the legs is met with in anaemia - a disease in which the blood is poor and watery - from mere passive transudation of the serum of the blood.

The immediate cause of dropsy is, as has been stated, a loss of balance between the exhalation and the absorption of serum; whilst the remote causes are improper food either in quality or quantity, and whatever tends to debilitate the general system.

Dropsy is accompanied by certain symptoms which vary considerably with its causes and complications. The symptoms of local dropsies correspond with the disturbance which local organs undergo in consequence of the accumulation, and of long-standing or recent disease. Old and worn out dogs are liable to dropsy from disease of the liver, when there axe, of course, indications of hepatic disturbance. Disease of the kidneys, by which the excretion of fluid is diminished, may give rise to dropsy. A quick, feeble pulse, loss of appetite, thirst, mange, piles, weakness, are some of the most marked symptoms which are present in dropsy.

For the treatment of dropsy, refer to the directions for the treatment of ascites, etc.