A weakness of the nervous system attendant on old age, or debility, or chronic lead poisoning often tells with force on the alimentary canal, and the loss of nervous power through disease of the great nerve centers (ganglionic system, brain, spinal cord) impairs the vermicular motion. This is notoriously the case in paraplegia, chronic hydrocephalus, and vertigo.
Finally among the causes of constipation must be noted the matting of the hairs around the anus (in dogs), and painful affections of the anus, or the abdominal walls, which render efforts at defecation painful and deter the animal from attempting them.
Lesions. These are as varied as the diseases which give rise to constipation, or result from it. Permanent dilatation or sacculation of the intestine, and the structural changes attendant on intestinal catarrh are the most common local lesions. But proctitis, hemorrhoids and ulcers of the anal follicles are met with in canine patients and ulcers of the colon in the seat of impaction are common.
Symptoms. In Solipeds the fæces are passed, at long intervals, in small quantity, usually only a very few balls at a time, firm, dry, moulded smooth and black on the surface, often covered with mucus, or with streaks of blood. They are passed with unusual effort and straining, and even with groaning, and one or more balls that may be exposed in the act are often drawn back and retained by the inversion of the rectum and closure of the sphincter. It is liable to be complicated by impaired appetite, tympanies, slight recurrent colics, and dryness, scurfiness and unthriftiness of the skin. Not unfrequently the pressure of the impacted colon (pelvic flexure) irritates the bladder causing stretching as if to urinate, and the passage of urine often in small quantity. There may be the symptoms of any one of the different nervous affections that lead to impaired peristaltic action, or of the local diseases which tend to obstruction of the bowels.
In dogs there are violent and painful efforts to defecate, which may be fruitless, or may lead to the expulsion of small masses of dry, earthy looking fæces, smoothly moulded on the surface, coated with mucus, streaked it may be with blood and highly offensive in odor. The anus may be puffy and swollen with mucopurulent secretion from the anal glands, which soils the hair of the hips and tail. If the abdomen is flaccid, manipulation with both hands on opposite sides usually detects a solid mass representing the impacted rectum and colon, and extending from the pelvis forward, often to the sternum. The same mass will be reached by the oiled finger introduced into the rectum. Both methods of exploration are painful and may call forth cries from the patient. The abdomen is usually distended, largely from the impacted fæces, in which case it gives a flat sound on percussion, or from gaseous emanation, in which case it is tense, resilient and resonant. Colicy pains are liable to appear, and vomiting at first of food only, then more or less yellow and bilious, and finally of distinctly feculent matters. For a time appetite may be retained, but this is gradually lost. There may supervene diarrhœa, which in favorable cases may lead to expulsion of the impacted mass, but in others it fails to completely dislodge it. The patient is dull and spiritless, inclined to lie curled up in dark corners, and when raised walks slowly and stiffly, with the tail carried straight or slightly to one side. The male urinates like a bitch without lifting the leg. The nose is dry, the tongue furred, the teeth usually covered with tartar, and the breath fœtid. There is at first no hyperthermia, but some rise of temperature attends on the advance of the disease, and the auto-poisoning by absorbed products of the putrefaction of retained fæces.
The disease may last a few days only or it may continue for weeks or months. In the last case intestinal catarrh, ulceration, and circumscribed necrosis are likely to supervene and the animal may die of auto intoxication, acute peritonitis or enteritis. Yet the majority of cases in the dog reach a favorable termination, or recover with remaining cicatrices, strictures or dilatations.
Treatment. In solipeds accustomed to an idle or pampered life, plenty of daily exercise will often correct the torpor. A run at pasture will often effectually counteract the tendency. If the patient must be kept in the stable a full drink of cold water every morning before feeding will often succeed. Regularity in feeding and watering is of the utmost importance, and the addition of a little wheat bran or flaxseed to the grain is often of material advantage. Next may be added a moderate allowance of carrots, turnips, or ensilage to furnish the needed succulence and organic acids. If in addition medicinal measures are wanted, a small handful of common salt, or of Glauber salts, in the morning drink to be taken ten or fifteen minutes before the first feed, will usually operate well. This may be continued for a length of time if necessary, without the ill effects of purgatives given at other times. It may be rendered slightly more effectual by the addition of 10 grains nux vomica on each occasion. A morning injection of a quart or two of cold water with one or two ounces of glycerine may be tried. Another resort is 2 or 3 grains of barium chloride in the morning drink or hypodermically repeated daily for some time.
In the more severe cases with already existing impaction of the colon, purgatives and copious injections will be demanded as advised under that disease.
In dogs the first object is the unloading of the rectum and colon and this usually demands direct mechanical intervention. (See Intestinal Indigestion with Constipation.) In case of hypertrophied prostate this may be rendered somewhat difficult, yet with a free use of oily, soapy or mucilaginous injections it can usually be accomplished.
The further treatment is on the same line as for the soliped. An abundance of exercise in the open air is a prime essential, together with a free access to fresh water. House dogs must be taken out for urination and defecation at regular times that are not too far apart. The food must be of a laxative nature. At first fresh whey or buttermilk only may be allowed, but as some action of the bowels is obtained well salted beef tea, pulped or scraped red muscle seasoned with salt, or milk treated in the same way is permissible. If the bowels fail to respond when the dog is taken out at the regular times an injection of cold water may be given. Sulphate of eserine (⅕ gr.) may be given daily by the mouth or hypodermically, or castor oil (½ to 1 oz.) may be administered at one dose to be followed by careful dietary and hygienic measures. Or sweet oil, calomel and jalap, podophyllin, or colocynth may be substituted. When the bowels have been freely opened a daily morning dose of a drop of the fluid extract of belladonna and ½ gr. of nux vomica will often materially improve the peristalsis. Active manipulation of the abdomen may be employed, or, if available, a current of electricity through the torpid bowels for 10 or 15 minutes daily.