Part 57

The phosphates of lime, magnesia, and of ammonia and magnesia usually constitute the main part of the calculus. Fürstenberg found specimens in which the ammonio-magnesian phosphate amounted to 72 to 94 per cent.

The calculi containing an excess of ammonio-magnesian phosphate tend to assume a crystalline or coralline form which causes them to be specially irritating to the mucosa. When broken they show a radiated structure from the centre to the circumference in addition to the concentric rings. These are usually of a yellowish brown or a gray color and have a specific gravity of 1694 to 1706.

Calculi in which the common phosphate of lime abounds are likely to be smooth on the surface and on section show the concentric rings more distinctly and the radiating lines less so. The brownish calculi of this variety are much more compact, and harder than the crystalline or mulberry calculi, and have a higher specific gravity—(1823).

Bluish calculi with a smooth glistening surface and lower specific gravity—1681—, have been found of small size and in great numbers in the colon (1000 in the colon, Gurlt).

In some calculi there is a large admixture of alimentary matters, and a low specific gravity (1605 to 1674). These were designated as pseudo calculi, by Fürstenberg.

In still other cases a calculous looking mass, when broken into, is found to be composed of a mass of dried alimentary matter enclosed in a thin layer of lime salts. These have a low specific gravity (1446 to 1566) and have been named concretions by Fürstenberg.

Causes. As a large proportion of the calculus is phosphate of lime or ammonio-magnesian phosphate, we must look for the source of these in the food and then at the conditions which determine their precipitation.

The percentage of ash and of phosphoric acid in the common foods of horses may be seen in the following table:

PO{5} in the PO{5} in the Ash. Ash. entire food. Per cent. Per cent. Per cent. Wheat bran 7.3 50 3.65 Wheat grain 3.0 46.38 1.3914 Oats grain 2.50 26.5 0.6625 Barley grain 3.10 39.9 1.2276 Bean grain 3.10 31.6 0.9864 Pea grain 2.75 34.8 0.957 Tare grain 3.00 36.2 1.086 Indian corn grain 1.5 Rye grain 1.6 39.9 1.0384

The source of the magnesia may be found to a large extent in the grains represented in the following table:

Ash. Mg. in Ash. Per cent. Per cent. Oat, grain 2.50 7.3 Barley, grain 3.10 8.5 Rye, grain 1.6 2.4 Wheat, grain 2.12 9.98 Wheat, bran 7.3 11.2 Bean 3.1 6.6 Pea 2.7 5.6

The amount of magnesia in each of these grains is amply sufficient to furnish the material for the constant growth of a calculus. Wheat bran is preëminent in the amount of its magnesia and therefore wheat bran has been charged with predisposing to calculi. In the perisperm as a whole, Fürstenberg found 1 per cent. of phosphate of magnesia, and in coarse bran not less than 2.5 per cent.

The ammonia which is essential to the precipitation of the phosphate of magnesia in the form of the compound salt (ammonio-magnesian) can be found wherever proteids are in process of septic fermentation. The slightest failure to peptonize every particle of such proteids, implies septic change and the evolution of ammonia, which on coming in contact with magnesia phosphate instantly precipitates the insoluble salt.

This fully agrees with the doctrine of the formation of urinary calculi through the agency of bacteria, since the ammonia is essentially a fermentation or bacterial product.

It may also be noted that the experiments of Rainey and Ord showed that in the presence of colloids (mucus, epithelium, pus, blood) the earthy salts are precipitated as minute globular bodies which by further accretions become calculi. In the absence of colloids the salts tend to precipitate in angular crystalline forms, so that the mulberry and coralline calculi may possibly have been precipitated in the absence of such bodies. From the solvent quality of ammonia, however, the contents may easily pass from a fermenting liquid containing colloids to a non-fermenting and noncolloid mixture.

The presence of a solid body which may act as a nucleus is an essential element, and the condition of the food or drink will often supply this. It has been noticed that army horses in the field, feeding from the ground and taking in sand and pebbles, are unusually liable to intestinal calculus. Horses which lick earth in connection with acidity of the stomach or other dyspepsia are specially subject to it. Horses watered from shallow streams with sandy bottoms, where they take in sand with the water, have been similarly affected. Millers’ horses, in the days of old process milling, suffered not alone because of the abundance of oat hairs in the feed but also on account of the grit from the millstones. Hay and other fodders that have lain on the ground and which contain earth and sand furnish other sources of such nuclei. Shingle nails and other small nails, pins, needles, coins, etc., which have mixed with the feed are common causes of trouble, and indeed any foreign body may become the centre and starting point of a calculus.

Catarrhal affections and other lesions of the mucosa, which furnish excess of mucus, beside pus, lymph and even blood as nuclei, are invoked as starting points of the calculi, but however true this may be in particular cases, irritation and catarrh appear to be much more frequently the result than the cause of the calculus.

Attempts have been made to estimate the time taken in the formation of a calculus by allowing a ring for each feed and successive deposit therefrom (Fürstenberg, Colin). Thus a calculus of 14 pounds with 720 layers, it was estimated could be formed in one year at two feeds per day. More definite evidence was found in the case of Pastore in which a coin with the mint mark of 1847 was found as the nucleus of a calculus the size of the fist in 1848.

Lesions. Formed in the most spacious parts of the colon and cæcum, calculi usually rest there for a length of time without visible injury, and it is only when they are moved onward and get arrested at a narrow part of the gut (pelvic flexure, floating colon, rectum) that they cause appreciable trouble. Yet it is claimed that by their weight they drag upon the yielding walls of the bowel, causing dilatation and attenuation, weakening the peristalsis and predisposing to rupture. The compression of the vessels also tends to anæmia and atrophy. In the case of rough crystalline calculi the mucosa is subjected to attrition, irritation, and inflammation. The more serious and urgent trouble is that of obstruction of the narrower portions of the colon and rectum, which may be absolute and persistent, leading to rupture and death or a fatal inflammation on the one hand, or may end in recovery on the other, in connection with a displacement onward or backward of the calculus as the result of peristalsis or anti-peristalsis.

Symptoms. These are intermittent colics, each reaching a climax and followed by a sudden recovery as the calculus is displaced into a more spacious part of the colon. A significant feature is the complete obstruction, fæces being passed for a short time at first and then suddenly and absolutely stopped. Coincident with this are tympany, violent colics, straining, rolling, sitting on the haunches, perspirations, anxious countenance, and all the symptoms of obstruction.

Diagnosis is never quite certain unless the practitioner with his oiled hand in the rectum can detect a hard stony mass obstructing the pelvic flexure of the double colon with a tense elastic distended bowel immediately in front of it, or a similar hard obstruction of the terminal part of the floating colon with a similar distension in front of it. The pelvic flexure may usually be felt below and to the right at the entrance to the pelvis, and the floating colon above, under the right, or more commonly the left kidney. Calculi in the more spacious parts of the double colon or in the cæcum are inaccessible to manipulation. The feed (bran, ground feed) will be suggestive, as will the occupation of the proprietor (miller, baker).

Treatment. This is rather a hopeless undertaking. No effective solvent of the calculus can be given, and purgatives usually increase the danger by increasing the peristalsis and dangerously distending the bowel above the point of obstruction. It is true that this is sometimes followed by a temporary recovery the calculus being loosened and falling back into the dilated portion of the bowel. Less frequently the increase in the peristalsis forces on a moderately sized calculus to complete expulsion. It is a desperate though sometimes successful resort. A more rational course of treatment is the dilation of the bowel back of the obstruction by copious mucilaginous, soapy or oleaginous enemata. Trasbot suggests CO_{2} produced by injecting sodium bicarbonate and tartaric acid. This may be seconded by the hypodermic injection of barium chloride or of atropia. When the calculus is lodged in the floating colon or rectum it may be possible to reach it with the hand and extract it at once. The last resort, is by laparotomy for the removal of the calculus. One such successful case is on record in which Filizet removed a calculus as large as an infant’s head. In other cases the horses failed to survive. Desperate as the resort may be it is not to be neglected in a case of undoubted calculus, solidly impacted and of such a size that its passage is impossible. A fatal result is imminent, and even if the present attack should pass off it can only be looked on in the light of an intermission, so that there is practically nothing to lose in case the result should prove fatal. Anæsthesia and rigid antiseptic measures should of course be adopted.

FOREIGN BODIES IN THE INTESTINES OF SOLIPEDS.

Sand, pebbles, earth, lime, nails, pins, needles, coins, shot, cloth, leather, rubber, sponge, tooth, bone, wood, twine. Symptoms: as in intestinal indigestion or calculi, or sand or pebbles in fæces; peritonitis, phlegmon. Lesions: congestion, catarrh, ulceration, abscess, needles may travel to other organs. Treatment: laxative, enemata, or as for calculi.

All sorts of foreign bodies are taken in with food and water and find their way to the intestines. Sand from drinking from shallow streams with sandy bottoms, from browsing on sandy pastures where the vegetation is easily torn up, or from feeding grain from sandy earth will sometimes load the intestines to an extraordinary extent so that such horses will pass sand for some weeks after leaving the locality. Small stones and gravel are taken in in the same way or from the habit of eating earth or licking crumbling lime walls. Nails, pins, needles, coins, shot, pieces of cloth, leather, caouchouc, sponge, and even a molar tooth and a piece of a dorsal vertebra have been thus taken. Recently the author saw a small twig of hard wood transfixing the pylorus and duodenum with fatal effect. In another case were balls of binding twine which had been taken in with the fodder on which it had been used.

The symptoms are usually those of intestinal indigestion or calculi. In some cases, however, they are peculiar, thus there may be a constant passage of sand, there may be indications of peritonitis, or there may form a phlegmonous swelling of the abdominal walls in the abscess of which the foreign body is found.

Lesions. Pechoux found 56 lbs. of a brownish earth in the cæcum and colon. Congestion and ulceration of the intestines are common, with occasionally abscess. All the lesions that attend on or follow obstruction may be met with. Boullon saw a remarkable case of the ingestion of needles in which these bodies were found in the small intestine, liver, pancreas, diaphragm, kidney and lung.

Treatment varies with the character of the bodies ingested, sand and gravel may be passed on by a laxative diet and even by the use of mild laxatives. Bernard gave 10 quarts of water and 4 oz. Glauber salts every hour for eight days, and the same amount by enema. For the larger solid bodies which obstruct the intestines the treatment is the same as for calculus. For sharp pointed bodies causing abscess and fistulæ, we must follow the indications, ever aiming at the discovery of the whereabouts of the offending object and its removal.