. - L_ZQ.;W!,Q'Q~JAIWMV _‘\-.f¥"-’ =,~,_ . "awn ~: .. ~ t‘ A » I VAAGIRBXPI‘. STATIIlNIl-"ILEI I I123) TEXAS AGRICULTURAL EXPERIMENT STATION. BULLETIN NO. 18. I OCTOBER, 1891. LIVER ITLUIIESi fl THE COMMON FLUKE (DISTOMUM HEPATIOUM). A NEW SPECIES (DISTOMUM TEXANICUM). AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS. All Bulletins 0f this Station are issued free. Any one interested in any branch of agriculture may have his name placed 0n our permanent mailing list, and secure future numbers, by ap- plication t0 GEO. W. CURTIS, DIRECTOR, College Station, Brazos 00., Tex. In requesting Bulletins, write name and address plainly. BRYAN, TEXAS! COX, “THE NEAT PRINTER.” 1891. ‘ T‘ ‘i (125) TEXAS AGRICULTURAL EXPERIMENT STATION OFFICERS AND STAFF. GOVERNING BOARD. BOARD OF DIRECTORS A. AND M. COLLEGE. MAJ. A. J RosE, President . . . . . . . .; . . . . . . . . . . . . . . . . . . . . . . . Salado. Hon. JNo. E. HOLLINGSWORTH. State Com. Agr . . . . . . . . . . . . . . .Austin. HON. W. R. CAVITT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bryan. DR. J. D. FIELDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Manor. Hon. JNo. ADRIANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Co1umbia. TREASURER. PRESIDENT L. S. Ross, . . . . . . . . . . . . . . . . . . . . . . . . . . ..Oo1lege Station. STATION STAFF. GEo. W. CURTIS, M. S. A . . . . . . . . . . . . . . . . . . . .Agricu1turist_. Director. H. H. IIARRINGTON, M. Sc. . . . ...; . . . . . . . . . . . . . . . . . . . Chemist. M. FRANCIS, D. V. M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Veterinarian. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Horticu1turist. D. ADRIANCE, M. S . . . . . . . . . . . . . . . . .Me1xaoro1ogist, Asst. Chemist. JD. W. CARSON, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assistant to Director. J. M. CARsoN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Assistant Agrioultllrist. P. S. TILSON, B. S. A . . . . . . . .i . . . . . . . . . . . . . . .Assistant in Cheznistry. (127) LIVER FLUKES. (M. FRANCIS, D. v. M.) The following account of liver-flukes and the disorders they pro- uee, is arranged in two parts. Part I gives an account of the com- on fluke (Distomum hepaticum), and part II gives a partial ac- pount of a species, new to Science, that is found, sometimes alone, jut usually associated with the former. I It is not generally known that the Trematoda bear an economic portance of the first magnitude to the live stock interests of Texas, ,1» it was deemed advisable to present the subject to the public through the Experiment Station Bulletins. It is now three years since the investigations here recorded were gun. At first the occurrence of enzootics of “Trematodism” were igarded as local, but on investigation it was found that these para- ptes cause serious damage almost every year, and that they are gore widely distributed than has been supposed. PART I. THE COMMON LIVER-FLUKE (Distmiwttwt H epatlicztrnz.) This well known parasite occurs in the livers of cattle. sheep and Its of Texas, in sufficient numbers to cause great damage. _ The irtion of the State permanently infected consists of the coast counties id the river bottoms. The specific area according to present infor- tion is shown on the map, plate VIII. I have found them also tside of the district indicated, but from the character of the coun- Ii I do not regard such localities permanently infected, or a source infection. he permanently infected district, consists of about two rows of ties along the coast from the Nueces river to the Sabine river, d the river bottoms of the San Antonio, Gaudalupe, Colorado, “razos, Trinity, Neches and Sabine. The condition along the Rio ande has not been determined. Mention should be made of the fed river bottom in the vicinity of Texarkana as infected. The ~ nd is mostly coast prairie, which is flat or slightly rolling. _ {Considerable timber occurs along the rivers. Some portions of e land is hog wallow prairie; other portions have large ponds in Thich grows a pod bearing shrub; these are called “bean-ponds. ” §~The river bottoms contain numerous bayous and over-flowed ces. a iLSDuring the rainy season this district becomes very Wet. The riv- Qj: over-flow their banks and all conditions are favorable for the etribution of parasites. An exception must be made of stock that quent the salt marshes inthe district, as these are comparatively from flukes. I iTEXAS AGRICULTURAL EXPERIMENT STATION. 128 TEXAS AGRICULTURAL EXPERIMENT STATION. nsscnrrrrorr OF rm}: PARASITE. - Body flattened, leaf like, pale brown, irregular, the adult from 1S to 31 mm long, from 4 to 13 mm wide, oblong, oval or lanceolate, larger and rounder in front. Where it is abruptly contracted in such a way as to present a conical neck; attenuate ard obtuse behind. Skin bristling with numerous little points directed backward. Oral sucker terminal, rounded. Ventral sucker large, projecting, with a triangular opening 3 mm behind the first. Intestine with two rami- fied branches visible through the skin and of a deep shade. Penis projecting in front of abdominal sucker, always recurved. Vulva very small, situated at the side of the male orifice or a little behind. Eggs brown or greenish, ovoid; length from 0.130 to 0145mm; width from 0.070 to 0090mm (Neuman). Copied from “Animal Parasites of Sheep,” by Dr. Cooper Curtice. The habitat of the adult fluke is the bile ducts of the liver of cat- tle sheep, goats and other ruminants, and occasionally in other do- mesticated animals. They are also reported by Murray in the lungs of Texas cattle. (Am. Vet. Review). The life history of the Parasite, as determiuedby Leuckart and by i Thomas is exceedingly interesting and wonderful. It is briefly as follows: The fertile eggs leave the adult fluke by the genital pore, in great numbers. They are carried through the bile ducts to the intestines, from which they pass with the excrement. If by good fortune they arrive in fresh water, the eggs hatch in from 3 to 5 weeks. The little lid on one end of the egg suddenly flies open from the struggling of the embryo within, and soon the embryo escapes. This embryo is just visible to the naked eye. It is pro- vided with fine hair-like projections, called cilia, which enables it to swim with great rapidity. In some experiments made in this laboratory some time ago, I was so fortunate as to witness the escape of the embryo as described. The time required for the eggs to hatch was 36 days in the first instance, and 34 days in the second, when kept in a watch glass at ordinary temperature. This embryo immediately seeks a fresh water mollusc, into whose body it bores its way with a beak-like projection with which the anterior portion of its body is provided. The English investigators have found L/ivnnaeustrunculatztrs as the host. If the embryo fails to find a suitable snail it soon dies. Those I had under observation died.in from 8 to 10 hours. Having a suitable mollusc, the embryo bores into the interior of its body by a rotary motion and encysts near the respiratory apparatus. It is now called a sporocg/st in whose interior new forms develope called writes. The rcdiaz produce in their interior other forms called cercrtr/ize which are active crea- tures. The cerccmiez: escape from the snail and encyst on the herbage which is devoured by animals, or they may be taken in the drinking water. They find their way to the liver where they develop into mature flukes and thus the cycle of life is completed. These changes or stages take place mostly during the summer months when molluscs are abundant and other rtonditions are favor- able. LIVER FLUKES. 129 For the details of these processes scientific readers are referred to the literature on the subject. EFFECTS OF THE PARASITE. The invasion of the liver by the oercaria is not manifested by un- favorable symtoms. Some observers assert that there is a marked tendency to fatten for about two months. Probably the first ‘thing to attract attention is the death of a few weak lambs early in the fall. The general havoc makes it appearance later, especially dur- ing the late winter or early spring. If present in limited numbers no marked deviations from health are noticed. So common are these parasites that it is exceptional to find a liver entirely free from them at any time of the year, and especially so during the spring. Even cattle slaughtered for beef, and in good condition, harbor a few dur-i ing the entire year. If the flukes are present in large numbers, serious damage results. Their presence in the bile ducts in sufiicient numbers, obstructs the free passage of that fluid and therefore increases the tension on the liver cells that secrete the bile; this causes a considerable quantity of the bile to enter the blood, and therefore the animals appear jaun- diced. a The walls of the bile ducts become thickened and are often coated with hard grit-like crusts. The bile becomes ropy and of a peculiar slimy appearance. These conditions existing, the circulation of the blood is retarded, the animals become pale (anaemic), weak, poor in flesh and dropsical. The dropsy of the abdomen is considerable and this gives the animal a “pot-lmllied” appearance. Dropsy appears, also, between the lower jaws on account of the position of the head when grazing. This condition is called “water-jaw.” As the dis- ease progresses, sheep lose portions of their wool. Extreme emacia- tion and debility follow, and frequently a profuse watery diarrhoea sets in which is usually fatal. The symptoms just stated are so conspicuous that stockmen call the disease “water-jaw and scours.” In the localities I visited I received the impression that heifers coming two years old suffered more than any other age. Many of these cattle and sheep die, and many of those that recover do not thrive the following summer, but remain poor and weak, and fail to breed. On post rnortem examination an enormous quantity of fluid (dropsy) is found in the abdomen; some of which is partly organ- ized. The liver is literally rotten and in its bile ducts, great num- bers of mature flukes are found. These on exposure extend and retract their bodies like a leech and eject the dark contents of their digestive ‘tract per mouth. They curl and soon die. Their eggs are seen in the gall and gall bladder in great numbers. . Frequently a few adult flukes are found in the small intestine. TREATMENT. Medicinal treatment is of little value. Some improxrement fol- lows the use of tonics, but very‘ little is accomplished. There can be no doubt as to the value oi a liberal use of salt. This is suggested by the fact that stock that have access to salt marshes are compar- atively free from flukes. 130 TEXAS AGRICULEEURAL EXPERIMENT STATION. PREVENTIVE TREATMENT. 4 As the development of the parasite in its various stages depends i on the presence of water and water animals, the disease can only . occur When stock have access t0 such stagnant ponds of Water which contain the cercarim or to grass or herbage that has grown in damp, wet places; it is evident that when these conditions dc not exist, the dsease cannot occur, that is, the parasite will fail to complete the cycle of life.’ The conclusion is obvious. Cattle and sheep must not have access to infected Water holes, but must be furnished pure Water. One large pasture company in San Patricio county has demon- strated that an abundance of suitable Water can be brought to the surface with xvind pumps at a small cost. Norm-The illustrations in this bulletin, with the exception of Plates II and VIII, are from photographs from nature by Dr. H. J. Detmers, Columbus, Ohio. Plates I. III. IV. V. VI. and VII. are each, enlarged one-ltalf. TEXAS AGRICULTURAL} EXPERIMENT STATION. PLF DISTQMUM HEPATICU M. Plate II, With explztriation as below given, is a reproduction from “Animal Parasites of Sheep,” by Dr. Cooper Curtice—by the courtesy of ll. S. Bureau of Animal Industry. l UISTOMIIBI HEPATTCUNI, Linn. PLATE II. Fig. 1. Adult fluke, natural size: 1w, young fluke, natural size. (Raillet) Fig. 2. Eggs: a, egg with developing embryo; b, egg with embryo; c, egg-shell. (Raillet) Fig. 3. Ciliated and free embryo: a, t$erforating apparatus; b, ocular spot. (Leuckart) A Fig. 4. Iilncutrsted embryo found in snails. (A. P. Thomas.) 5 Diagram of digestive apparatus and nervous system: a, mouth sucker; h, pharnyx; c, oesophagus; d, branches ofintestine; e, theirbranchlets: ‘f, nerve ganglia; g, ventral nerve. (Raillet) ITig. (i. Lirnvzzrus ZT’LL7’LClLZ@iZ(-S', the principal snail “ihich is the larval host of the fluke in Europe: a, natural size. (Raillet) Fig. 7. Redia of Di-siolmztm laepai/icztnz: a, mouth; h, pharynx; c, digestive tube: <1, the so-called germinative cells destined to produce cercaria» (Leuckart) Fig. 8. Redia containing cercariae: a, mouth; b, pharnyx; r, (ligestive tube; (l, 1/. cercarize. (Leuckart) 9. (‘ercaria dissected from its (iyst; a, anterior sucker; l», ventral sucker: c, pharnyx; d, d, branches of the ‘intestine terminating in ca-Pra. (Leuclzarh) "- i li‘ig. l0. Grass stalk With three encysterl young flukes, a, (t. (A. P. 'l‘homas.l lilig. l1. iilree-stvimrning tiercttria just before it is about to encyst. (A. l’. ’l‘h