Part 44

Causes. Predisposing causes embrace such as induce weakness or debility, youth, low condition, cold intemperate weather, extreme heats, musty or spoilt fodders.

The essential cause, the coccidium, appears to be taken in with food or water as sucking calves are largely exempt. The parasite is found in the gastric and intestinal epithelium of the diseased animals, in numbers proportionate to the severity of the attack, being very abundant when the disease is at its height, diminishing during convalescence, and disappearing entirely on recovery. Two species are found in this disease.

=Coccidium Oviforme= is 40 to 50μ long by 22 to 28μ thick, ovoid, with a double outlined limiting membrane enclosing a refrangent protoplasm with a nucleus two or three times as large as that of an epithelial cell, and staining with hæmatoxylon or aniline colors. The young coccidia appear as round granular protoplasmic masses, without a capsule but provided with a nucleus. At first of a diameter of 9 to 10μ they increase to 26μ retaining the spherical form and acquiring the membrane of the mature parasite. As it grows the protoplasm separates from the wall and forms a globular nucleated mass, which after fifteen days divides into two and later into four masses or sporoblasts. Each sporoblast in its turn divides into two falciform corpuscles lying in contact but in an inverse sense to each other. Each of these under favorable conditions becomes a new amœboid individual capable of invading an epithelial cell and passing through the same stages of development as its predecessor.

The coccidium oviforme is found in the epidermis in cutaneous psorospermosis of birds, and in the coccidian hepatitis in rabbits.

=Coccidium Perforans.= In its mature form this is 25μ to 35μ long, by 14μ to 20μ broad. Its different stages of evolution are essentially the same as for the Coccidium Oviforme. It is a cause of intestinal Coccidiosis in both dog and rabbit as well as in cattle, usually killing the rabbit in from eight to ten days.

Lesions. In the first reported cases in calves in 1877 (Proger and Zurn), there was catarrhal inflammation of the upper air passages as well as the bowels. There was thickening, redness and desquamation of the abomasum near the pylorus of the small intestine and colon. In the intestines there were patches of thickening and softening of the mucosa and miliary ulcers with yellowish contents. The mesenteric glands, liver and spleen were enlarged, softened and ecchymosed. In all the lesions coccidia were found. In the cases reported by Hess, Zschokke, Guillebeau and Cadeac the abomasum and large intestine principally suffered. There was a diffuse inflammation of the mucosa and in the rectum and portion of the colon a great degeneration and desquamation of the epithelium. The columnar cells of the mucous glands especially suffered. A single cell would contain five or six psorosperms, in different stages of development. If the parasites have escaped, the cell walls are pressed together. Among the diseased glands others with healthy epithelium were found, their orifices plugged with mucus. Both forms of coccidia above described are found in two conditions, in the epithelial cells with granular nuclei staining in hæmatoxylon, and violet or black with iodine (Lugol’s), and outside the cells with granular nucleus or simple hyaline contents which do not stain. Zschokke considers the latter as in process of degeneration. Other organs are anæmic.

Symptoms. The disease is ushered in by cold extremities, weakness, dullness, suspended rumination, ardent thirst, hyperthermia, 102° to 104° and even 106°, small, weak thready pulse beating 100 to 140 per minute, sunken eyes, grinding of the teeth, and defecation in small quantity only. Toward the fourth day or earlier a fœtid diarrhœa sets in, watery, bloody and fibrinous. The bloody discharges last to the seventh day, the diarrhœa to the end of the second or fourth week. Straining may be violent, exposing or everting the irritated or ulcerated rectum, the hind parts may be stiff, the patient rises with difficulty, he winches if pressed on the back or right side of the abdomen, loses flesh rapidly and becomes a walking skeleton. when the discharges are less profuse cylindroid croupous casts are sometimes expelled.

Course. Duration. In the weak and young a violent attack may prove fatal in 24 hours. In others the malady lasts for two or more weeks and sometimes relapses, and the patient becomes very weak and anæmic. Complications of various kinds may also supervene and cut off the animal, the lesions and debility alike favoring the introduction of the germ. Thus black quarter, bronchitis, pneumonia, convulsions, paralysis, phthiriasis and ring-worm have been noted as sequelæ.

Diagnosis can always be made by microscopic examination of the fresh warm fæces.

Prevention. This will consist in the avoidance of water and of green food from soils where the disease has been found to prevail.

Treatment. Antiseptics given by the mouth have proved of very little avail having as a rule lost their power through dilution in the contents of the stomachs. They may still be given to keep in check the propagation of the coccidia in the fourth stomach. Silver nitrate, iron sulphate, lead acetate, tannic acid, oak bark, carbolic acid, cresol, lysol, salicylic acid, hydrochloric acid, sulphuric acid, hyposulphite of soda have been used in this way. The same agents may be used with better effect as enemata being forced as far as is consistent with safety and frequently repeated. Quinia and iodide of potassium may also be given as parasiticides. Mucilaginous gruels and decoctions should be given at first, followed by mashes as they can be borne, but the food must be moderate and easily digestible until full convalescence has taken place.

The flesh of animals killed while suffering from this affection has been eaten by man with impunity.

COCCIDIAN ENTERITIS IN THE DOG. INTESTINAL COCCIDIOSIS.

Causes. Two parasites have been found in connection with this disease in the dog; the =Coccidium penetrans=, already described, and the =Coccidium bigeminum=.

=Coccidium Bigeminum, var. Canis.= This is elliptical and from 12 to 15 μ long by 7 to 10 μ broad. They are usually found in pairs lying side by side, and sometimes both in the same envelope indicating multiplication by division along the longitudinal axis.

The bigeminum is held to be harmless, but the perforans, as in the cow and rabbit is very injurious and even fatal. The symptoms are those of digestive disturbance, dullness, loss of appetite, retching, vomiting, colic and fœtid and bloody diarrhœa. Irritability, and a morose disposition and loss of control over the hind limbs have been set down as rabiform indications.

Diagnosis depends on the inveteracy and sanguineous nature of the diarrhœa, but especially on the discovery of the amœboid organisms in the recent, warm discharges.

Treatment should be along the same line as in cattle.

COCCIDIAN ENTERITIS IN RABBITS. INTESTINAL COCCIDIOSIS.

Causes. In rabbits the coccidium perforans is the psorosperm which usually attacks the bowels. The coccidium oviforme which produces hepatic coccidiosis is also occasionally found in the intestines. The perforans is smaller than in cattle being 15 to 25 μ long, by 12 to 15 μ broad, approximating to the variety found in man.

Lesions. There is extensive congestion of the intestinal mucosa, with thickening and softening of the epithelium so that it breaks down into a pulp under pressure, also free desquamation with the formation of abrasions, sloughs and ulcers. In some instances extensive croupous casts of the intestine are found. As in the other animals the coccidium is found abundantly in the epithelial cells of the affected parts which swell up and degenerate. When the parasite has escaped from the cells it lives free in the abundant mucopurulent and sanguineous secretions of the bowels.

Symptoms. There are loss of appetite, swelling of the abdomen, profuse diarrhœa, the fæces yellowish in color and containing mucopurulent matters and blood. The disease may prove fatal in a few days without much loss of flesh, but if protracted it leads to extreme anæmia, emaciation and debility and the animal dies in marasmus.

Diagnosis is always to be certified by the profusion of coccidia found in the fresh liquid discharges.

Prevention must be secured if possible by the removal of the healthy rabbits from the infected and from the hutch or warren in which the latter have been. The greatest care must be taken to prevent them from obtaining access to the droppings of the sick, or to streams, ponds or wells, into which the drainage from such manure can have found its way. The safest course is to destroy the sick and burn up them and all their droppings, as the latter ground into powder can blow on the wind.

Therapeutic treatment has proved unsatisfactory but may be attempted along the same lines as for the larger animals.

COCCIDIAN ENTERITIS IN BIRDS. INTESTINAL COCCIDIOSIS.

Two sporozoa are known to be pathogenic in the intestines of birds: the =coccidium tenellum= and the =gregarina avium intestinalis=.

=Coccidium Tenellum.= This has a nearly globular body 21 to 25 mm. long by 17 to 19 mm. broad, a very thin, delicate investing membrane, and has been found in the mucosa of the cæca of birds, producing a fatal typhlitis. The sporoblasts are developed in water outside the animal body and when taken in with the food colonize in the intestinal mucosa.