Causes—­Very numerous.  In weakly dogs exposure alone will produce it.  The weather, too, has no doubt much to do with the production of diarrhoea.  In most kennels it is more common in the months of July and August, although it often comes on in the very dead of winter.  Puppies, if overfed, will often be seized with this troublesome complaint.  A healthy puppy hardly ever knows when it has had enough, and it will, moreover, stuff itself with all sorts of garbage; acidity of the stomach follows, with vomiting of the ingesta, and diarrhoea succeeds, brought on by the acrid condition of the chyme, which finds its way into the duodenum.  This stuff would in itself act as a purgative, but it does more, it abnormally excites the secretions of the whole alimentary canal, and a sort of sub-acute mucous inflammation is set up.  The liver; too, becomes mixed up with the mischief, throws out a superabundance of bile, and thus aids in keeping up the diarrhoea.

Among other causes, we find the eating of indigestible food, drinking foul or tainted water, too much green food, raw paunches, foul kennels, and damp, draughty kennels.

Symptoms—­The purging is, of course, the principal symptom, and the stools are either quite liquid or semi-fluid, bilious-looking, dirty-brown or clay-coloured, or mixed with slimy mucus.  In some cases they resemble dirty water.  Sometimes, as already said, a little blood will be found in the dejection, owing to congestion of the mucous membrane from liver obstruction.  In case there be blood in the stools, a careful examination is always necessary in order to ascertain the real state of the patient.  Blood, it must be remembered, might come from piles or polypi, or it might be dysenteric, and proceed from ulceration of the rectum and colon.  In the simplest form of diarrhoea, unless the disease continues for a long time, there will not be much wasting, and the appetite will generally remain good but capricious.

In bilious diarrhoea, with large brown fluid stools and complete loss of appetite, there is much thirst, and in a few days the dog gets rather thin, although nothing like so rapidly as in the emaciation of distemper.

The Treatment will, it need hardly be said, depend upon the cause, but as it is generally caused by the presence in the intestine of some irritating matter, we can hardly err by administering a small dose of castor oil, combining with it, if there be much pain—­which you can tell by the animal’s countenance—­from 5 to 20 or 30 drops of laudanum, or of the solution of the muriate of morphia.  This in itself will often suffice to cut short an attack.  The oil is preferable to rhubarb, but the latter may be tried—­the simple, not the compound powder—­dose from 10 grains to 2 drachms in bolus.

It the diarrhoea should continue next day, proceed cautiously—­remember there is no great hurry, and a sudden check to diarrhoea is at times dangerous—­to administer dog doses of the aromatic chalk and opium powder, or give the following medicine three times a day:  Compound powdered catechu, 1 grain to 10; powdered chalk with opium, 3 grains to 30.  Mix.  If the diarrhoea still continues, good may accrue from a trial of the following mixture:  Laudanum, 5 to 30 drops; dilute sulphuric acid, 2 to 15 drops; in camphor water.