LIBRARY, A & M COLLEGE. CAMPUS. nzxns AGRICULTURAL EXPERIMENT sfiilfiiffimg’ A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 457 SEPTEMBER, 1932 ... a; 4 DIVISION OF VETERINARY SCIENCE . w" )- 1* pg‘, 3 i SOREMOUTH (CONTAGIOUS ECTHYMA) 1N1?» SHEEP AND GOATS E AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. O. WALTON, President STATION STAFF’; Administration: A. B. Conner, M. S., Director R. E. Karper, M. S., Vice-Director Clarice Mixson, B. A., Secretary M. P. Holleman, Jr., Chief Clerk J. K. Francklow, Asst. Chief Clerk Chester Higgs, Executive Assistant Howard Berry, B. S., Technical Asst. Chemistry: G. S. Fraps, Ph. D., Chief; State Chemist . E. Asbury, M. S., Chemist F. Fudge, Ph. D., Chemist . C. Carlyle, M. S., Asst. Chemist L. Ogier, B. S., Asst. Chemist . J. Sterges, M. S., Asst. Chemist Ray Treichler, M. S., Asst. Chemist W. H. Walker, Asst. Chemist Velma Graham, Asst. Chemist Jeanne F. DeMottier, Asst. Chemist R. L. Schwartz, B. S., Asst. Chemist C. M. Founders, B. S., Asst. Chemist Horticulture: S. H. Yarnell, Sc. D., Chief "L. R. Hawthorn, M. S., Horticulturist H. M. Reed, B. S., Horticulturist J. F. Wood, B. S.; Horticulturist L. E. Brooks, B. S., Horticulturist Range Animal Husbandry: J. M. Jones, A. M., Chief _ B. L. Warwick, Ph. D., Breeding Investiga. S. P. Davis, Wool Grader Entomology: F. L. Thomas, Ph. D., Chief; State Entomologist H. J. Reinhard, B. S., Entomologist R. K. Fletcher, Ph. D., Entomologist W. L. Owen, Jr., M. S., Entomologist J. N. Roney, M. S., Entomologist J. C. Gaines, Jr., M. S., Entomologist S. E. Jones, M. S., Entomologist F. F. Bibby, B. S., Entomologist S. W. Clark, B. S., Entomologist "E. W. Dunnam, Ph. D., Entomologist "R. W. Moreland, B. S., Asst. Entomologist C. E. Heard, B. S., Chief Inspector C. Siddall, B. S., Foulbrood Inspector S. E. McGregor, B. S., Foulbrood Inspector wflssw Veterinary Science: *M. Francis, D. V. M., Chief H. Schmidt, D. V. M., Veterinarian I. B. Boughton, D. V. M., Veterinarian **F. P. Mathews, D.V.M., M.S., Veterinarian W. T. Hardy, D. V. M., Veterinarian ———————, Veterinarian Plant Pathology and Physiology: J. J. Taubenhaus, Ph. D., Chief W. N. Ezekiel, Ph. D., Plant Pathologist W. J. Bach, M. S., Plant Pathologist C. H. Rogers, Ph. D., Plant Pathologist Farm and Ranch Economics: L. P. Gabbard, M. S., Chief W. E. Paulson, Ph. D., Marketing C. A. Bonnen, M. S., Farm Management **W. R. Nisbet, B. S., Ranch Management **A. C. Magee, M. S., Farm Management Rural Home Research: Jessie Whitacre, Ph. D., Chief Mary Anna Grimes, M. S., Textiles Elizabeth D. Terrill, M. A., Nutrition Soil Survey: **W. T. Carter, B. S., Chief E H. Templin, B. S., Soil Surveyor A. H. Bean, B. S., Soil Surveyor R. M. Marshall, B. S., Soil Surveyor Botany: V. L. Cory, M. S., Acting Chief S. E. Wolff, M. S., Botanist Swine Husbandry: Fred Hale, M. S., Chief Dairy Husbandry: O. C. Copeland, M. S., Dairy Husbandman Poultry Husbandry: R. M. Sherwood, M. S., Chief J. R. Couch, B. S., Asst. Poultry Hsbdman Agricultural Engineering: H. P. Smith, M. S., Chief Main Station Farm: G. T. McNess, Superintendent Apiculture (San Antonio): H. B. Parks, B. S., Chief A. H. Alex, B. S., Queen Breeder Feed Control Service: F. D. Fuller, M. S., Chief James Sullivan, Asst. Chief . S D. Pearce, Secretary '*%r";:.'"§:,..... D. Chief J. H. Feed R_ E_ Karper ’M_ S_ Agronomist K. L. Kirkland, B. S., Feed Inspector P. C. Mangelsdorf Se. D. Agronomist S- D- Reynelds- Jr" Feed Inspector D. T. Killough S. Agronomist P- A- Moore» Feed Inspect“ H_ E_ Rea B 'S_ Agionomist E. J. Wilson, B. S., Feed Inspector B_ C_ Laughs}, S" Agronomist H. G. Wickes, B. S., Feed Inspector Publications: A. D. Jackson, Chief SUBSTATIONS No. l, Beeville, Bee County: R. A. , B. S., Superintendent No. 2, Lindale, Smith County: P. R. Johnson, M. S., Superintendent “B. H. Hendrickson, B. S., Sci. in Soil Erosion "R. W. Baird, B. S., Assoc. Agr. Engineer No. 3, Angleton, Brazoria County: R. H. Stansel, M. S, Superintendent H. M. Reed, M. S., Horticulturist No. 4, Beaumont, Jefferson County: R. H. Wyche, B. S., Superintendent "H. M. Beachell, B. S., Jr., Agronomist No. 5, Temple, Bell County: Henry Dunlavy, M. S., Superintendent C. H. Rogers, Ph. D., Plant Pathologist H. E. Rea, B. S., Agronomist S. E. Wolff, M. S., Botanist "H. V. Geib, M. S., Sci. in Soil Erosion “H. O. Hill, B. S., Jr. Civil Engineer No. 6, Denton, Denton County: P. B. Dunkle, B. S., Superintendent "I. M. Atkins, B. S., Jr. Agronomist No. 7. Spur, Dickens County: R. E. Dickson, B. S., Superintendent B. C. Langley, M. S., Agronomist No. 8, Lubbock, Lubbock County: D. L. Jones, Superintendent Frank Gaines, Irrig. and Forest Nurs. No. 9, Balmorhea, Reeves County: J. J. Bayles, B. S., Superintendent No. 10, College Station, Brazos County: R. M. Sherwood, M. S., In Charge L. J. McCall, Farm Superintendent No. 11, Nacogdoches, Nacogdoches County: H. F. Morris, M. S., Superintendent **No. 12, Chillicothe, Hardeman County: J. R. Quinby, B. S., Superintendent **J. C. Stephens, M. A., Asst. Agronomist No. l4, Sonora, Sutton-Edwards Counties: . H. Dameron, B. S., Superintendent I. B. Boughton, D. V. M., Veterinarian W. T. Hardy, D. V. M., Veterinarian O. L. Carpenter, Shepherd **O. G. Babcock, B. S., Asst. Entomologist No. 15, Weslaco, Hidalgo County: W. H. Friend, B. S., Superintendent S. W. Clark, B. S., Entomologist W. J. Bach, M. S., Plant Pathologist J. F. Wood, B. S., Horticulturist No. 16, Iowa Park, Wichita County: C. H. McDowell, B. S., Superintendent L. E. Brooks, B. S., Horticulturist No. 19, Winterhaven, Dimmit County: E. Mortensen, B. S., Superintendent “L. R. Hawthorn, M. S., Horticulturist Teachers in the School of Agriculture Carrying Cooperative Projects on the Station: G. W. Adriance, Ph. D., Horticulture S. W. Bilsing, Ph. D., Entomology V. P. Lee, Ph. D., Marketing and Finance D. Scoates, A. E., Agricultural Engineering A. K. Mackey, M. S., Animal Husbandry *Dean School of Veterinary Medicine. “In cooperation with J. S. Mogford, M. S., Agronomy F. R. Brison, B. S., Horticulture W. R. Horlacher, Ph. D., Genetics J. H. Knox, M. S., Animal Husbandry A. L. Darnell, M. A., Dairy Husbandry iAs of April 1, 1932. U. S. Department of Agriculture. Soremouth (Contagious Ecthyma) in sheep and goats is an infectious disease and occurs especially in young animals. It is quite prevalent on the range in the sheep and goat-raising area in western Texas and elsewhere. Sometimes it is also very troublesome among feeder lambs in the feed lot. Older animals may also be infected artificially. The disease manifests itself by a swelling of the lips followed by papules, vesicles, pustules, and scab formation so that the lips in the end become stiff, unpliable, and covered with crusts. The crusts are finally shed and the lesions heal without leaving a scar. The disease itself is not very fatal but losses from screw-worm infestation of the lesions, from reduced thriftiness of the young ani- mals, or from shrinkage in the feed lots may be very heavy. The virus of the disease is not known. It has been reported as filterable. Our results confirm those of others that filtration is difficult to obtain. The lesions remain localized irrespective of the site of inoculation. Our re- sults and those of others indicate that one attack of the disease leaves a well marked immunity and that such an immunity develops irrespective of the location of the lesions on the skin. We propose to utilize this fact and inoculate the young animal on some part of the body other than the lips before screw-worm time arrives. CONTENTS Page Introduction 5 The disease as it occurs naturally 8 The development of the disease following inoculation .............................. -- 9 Transmission of the disease 12 Different strains of virus 13 Susceptibility of animals ' 14 Filtration experiments 15 Immunity tests 18 Treatment 20 Summary 20 BULLETIN NO. 457 SEPTEMBER, 1932 SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS* H. Schmidt and W’. T. Hardy In the sheep-raising area in the western part of the State a condition occurs among sheep and goats that the ranchmen refer to as soremouth. This condition, manifesting itself mainly in a painful swelling of the lips and the appearance thereon of papules, vesicles, and pustules which soon break, after which the affected parts become covered with thick, tightly- adhering grayish-brown crusts, has been known to the ranchmen for a number of years but until recently efforts had not been made to study the disease, mainly because the mortality, as a rule, had remained very low. Other losses, however, resulting from this trouble such as numerous cases of screw-worm infestation, losses due to undernourishment in affected young lambs and kids, and heavy shrinkage in the feed lot, if the disease should break out there, have brought forth requests by ranchmen that something be undertaken to avoid these occurrences. Since, in our y opinion, the cause and nature of the disease were still in doubt, experi- ments were planned and started at the Ranch Experiment Station early in 1928 and later participated in by the Main Station at College Station with the view of studying the nature of the disease and to find some practical remedy for it. In the older literature a similar disease has been described as necro- V bacillosis (10, 11), lip-and-leg ulceration (14), etc., and attributed to the _ Actinmnyces necrophorus. There is no doubt that this organism has been found in the lesions of the disease described but it is not clear whether j? it has been established as the primary cause or whether it was only present as an occasional secondary invader. The photographic illustra- tions accompanying these discussions showed lesions of the mouth of tglisheep and goats strikingly similar to those observed by us, but other ilesions, notably ulcers on the legs as reported by Mohler, were not ob- iiserved by us. i‘ This was the extent of the literature available to us at the time our first experiments were undertaken. As current literature became avail- able it was searched and a number of references found that threw addi- tional light on the subject. Jacotot (1), in 1924, speaks of a contagious 5ecthyma of the fps of goats in Annam, Indo-China, and describes lesions Zhat resemble thore observed by us. He pointed out that the submaxillary gymph glands are severely inflamed and that recovery leaves a durable immunity. In 1928 Theiler (2) published his observations on contagious _ thyma of sheep and goats as observed in South Africa and also reviewed dome literature on the subject. The lesions as observed by Theiler also losely parallel those observed by us. Theiler could verify the findings others that the disease could readily be transmitted from animal _to 'mal by lightly scarifying the skin and applying some of the emulsi- 1' art of the work carried on by E. A. Tunnicliff, resigned December, 1929. } 6 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION fied material from the lesion, an observation which in the meantime had also been made by us. He records that Zeller, Blanc, and Aynaud,* succeeded in filtering the virus, although Zeller did not succeed in all cases when using Berkefeld filters V or Nordtmeyer Berkefeld filters. Aynaud used Chamberland filters L1 and L2 bis, and Blanc used Chamber- land L2 filters. Theiler himself obtained negative results in his filtration ex- periments when using Seitz asbestos filters. In a later publication (15) Jacotot reports that he succeeded in filtering the virus of contagious ecthy- ma of the goat through Chamberland filters F and L2. In 1928 Melanidi and Stylianopoulo (13) published on contagious ecthyma of sheep in Greece and reported that this disease had not hitherto been observed in that country (Blank and co-workers reported it from Greece in 1922) and expressed the belief that the disease was introduced with importations of sheep from Syria and northern Africa. In this outbreak the losses varied from 5% to 60% and were mostly due to inanition and pulmonary or intestinal comlplications. The authors point out that the disease resembled that described from France in every respect; that it was charac- terized by the formation of ulcers and scabs on the lips, nostrils, and buccal cavity; that these eruptions were preceded by a fever; and that the regional lymph glands were affected. These authors speak of vaccinating against this disease with good results. Glover (12) in 1928, reported the results of some of his work with con- tagious pustular dermatitis or stomatitis (Contagious Ecthyma) of the sheep in England and gave a description of the microscopical skin lesions. He found that the virus is filterable with difficulty and that sheep and goats alone are susceptible to it; that it is highly resistant to desiccation and that animals recovered from an attack of the disease remain resistant to further attacks for at least eight months. He could transmit the dis- ease with a few drops of suspension made with dry scab material diluted 1 to 50,000. He could not transmit the disease by intradermal inocu- lation of blood drawn after pustules had formed. Neither could he produce skin lesions of the disease when he inoculated the virus subcu- taneously or intravenously. His attempts to transmit the disease to- the rabbit, guinea pig, mouse, fowl and pigeon were all negative. Glover also reports, that in the experience of Aynaud, if sheep are inoculated on the thigh with suitable material which produces a benign local reaction there need be no apprehension of a generalisation of the disease. Carre (8), in a discussion of some diseases among sheep, states that Ay- naud established that ecthyma and ulcerous stomatitis were manifesta- tions of the same disease, which was caused by a filterable virus. Ac- cording to this author ulcers may develop about the mouth, gums, pharynx, and oesophagus and even inflammatory patches in the intestines and in- volvement of the lungs may be observed. Such lesions were more re- cently reported by Newsom and Cross (6) as complications of soremouth in lambs. According to these authors “there is still some question about the etiology of soremouth but there can seemingly be no doubt that these *The publications of these three authors are not available to us. SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 7 complications are due to invasion of Actinomyces necrophorus.” Accord- ing to Carre (8), opinion is divided as to an immunity. The disease naturally acquired is said to give immunity for 21/2 years, while sheep experimentally infected acquire the affection after one year. Ulcers and similar lesions on the digestive mucosa of sheep and goats had already been reported by Miegeville (9) in 1927, from Morocco. This author states that the disease is known as contagious ecthyma of the lip or ulcerous stomatitis, but is of opinion that two distinct diseases are involved, namely, contagious ecthyma occurring especially in adults and ulcerous stomatitis occuring especially in lambs and kids, which latter form may in- volve the mucosa of the mouth, pharynx, oesophagus, and intestines, and also the lungs. Willems (3), in 1929, speaks of contagious ecthyma of the lips of sheep as occurring in Belgium and suggests the possibility of its transmission to man. In 1930 Hatziolos (4) reported his observations on an epizootic of contagious ecthyma of the lips which he observed during the warm season in 1929 occurring among sheep over a large part of Greece and in which he reports losses ranging from 5% to 60%. In his obser- vations the disease remained confined to sheep and was not transmitted to goats living in contact with affected sheep. He, too, reports the trans- mission‘ of the affection to man and observed the occurrence of stomatitis with vesicles on the gums, tongue, cheeks, and lips of the shepherds and their children. He also speaks of vaccinating the sheep much in the same way as it is practiced in the human subject against smallpox and gives a simple method of preparing the vaccine. Vaccinated animals left in con- tact with sick ones did not contract the disease. In 1930 Seddon (5) describes the disease from Australia. This investi- gator was able to reproduce the disease with filtered material and states that the virus is too small to be seen with the highest powers of the microscope. He also reports that lesions sometimes occur on the inside i of the lips, on the gums, dental pad, or palate. He observed that sheep which have recovered from an attack of the disease are immune from l_ further infection and that sheep may be artificially immunized by vacci- nating them much in the same way as the vaccination is carried out for the human subject against smallpox. Recently Howarth (7) reported an out- break of the disease from California. He could readilytransmit the dis- l; ease to sheep and a goat by applying emulsified scabs or other infective material to the scarified skin. He was unable to find any evidence of the presence of Actinomyces necrophorus either in cultures or animal Q inoculation experiments. On the other hand he succeeded in passing the i’ virus through a Mandler and Chamberland L2 filter but speaks of the l difficulty encountered in obtaining uniform results. Attempts to infect T three guinea pigs, two rabbits, two pigs, a dog, and a cow gave negative f results in all cases. 8 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION THE DISEASE AS IT OCCURS NATURALLY In our investigations we have found that soremouth in the field usually occurs only in young animals, either in the suckling lamb or kid or after the lamb or kid has been weaned or has probably been placed in the feed lot. Only rarely are cases observed in older animals. The first symptoms that the ranchman usually observes are swelling of the lips, which soon become more or less inflamed and are later covered by more or less pro- fuse scab formation. A closer examination will show that the swelling when it first appears is usually confined to the lips and that the skin of these also shows the formation of papules, vesicles, and pustules. These lesions need not remain confined to the lips, but may spread either to the buccal mucous membrane or to the hairy skin farther removed from the lips. In the latter case they, nevertheless, remain confined to the nose or the cheeks. These scabs or crusts will become thicker as time goes on and may reach a thickness of one-half inch or more. They are dry and grayish-brown to dark-brown in color. Their surface may become deeply-fissured and cracked. These cracks are sometimes so deep that the whole mass of crusts may appear as two or more warty protubances. In the course of three or four weeks such scabs will gradually crumble away and finally disappear, the condition healing without leaving a scar. If, however, such scabs are forcibly removed either accidentally by the animal itself or otherwise, a painful, raw, bleeding surface will be left, which in the course of time will become covered with new scabs which, in due time, will drop off, and the lesion will have healed without leaving a scar. The lesions do not always show such a grave character as just de- scribed but rather vary a great deal from season to season, from flock to flock or even within the same flock. Often we see only insignificant scab formation at varying places on the lips, but perhaps most frequently at the commissures. We have observed the development of lesions on the udder, under the tail, and on the ears. Other observers have reported them on the udder, on the under surface of the tail, on the feet, on the thighs, and in the axillae. From these observations it appears that unless the lesions ape- pear on the lips or feet they are frequently found on that part of the skin devoid of wool or hair. The inflammation of, and the marked scab formation on, the lips leaves these in a stiff, leathery, unpliable condition, every movement of which is more or less painful, thus greatly interfering with the suckling of the young or with the prehension of food to the extent that affected animals lose in condition and sometimes even die. Moreover, since soremouth oc- curs in the season of the year when the screw-worm fly is most active, screw-worm infestation of the affected parts is rather common. Indeed, the losses from screw-worm infestation, both in labor involved in caring for such cases and loss of animals as the result of such screw-worm infes- tation, is perhaps greater than that caused by the soremouth condition itself. SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 9 THE DEVELOPMENT OF THE DISEASE FOLLOWING INOCULATION The development of the lesions can best be studied 0n the soft skin devoid of wool or hair as it is found on the under surface of the tail or on the internal aspect of the thigh in the sheep or the goat. If this area be carefully and thoroughly cleaned, then lightly scarified so as to break the superficial epidermis but not deep enough to draw blood and then an emulsion of virulent virus be applied, the development of the different stages of the lesions can be clearly observed. On an area thus inoculated one will see within the first 24 to 48 hours a slight reddening and swell- ing of the skin along the line of scarification, which may increase in in- tensity during the next day or two. Upon careful observation one may at _, this time also see along the line of scarification_, small circumscribed I areas, which are slightly raised above the general level of the skin. These 1 are called papules and represent a marked, sharply circumscribed infiltra- tion of the skin. At the tip of each papule a small vesicle soon appears which at first is filled with a clear, transparent fluid. This fluid, how- i‘ ever, soon becomes turbid thus converting the vesicle into a pustule over which the raised epidermis stretches as a thin, glistening membrane. In awthe degree that the fluid in the pustule increases in amount the pustule ,7 will increase in size both as regards its diameter at the base and its ele- f vation. In places protected from mechanical insults such pustules may become hemispherical in shape and have a base two or three millimeters or more across. In some cases the lines of scarification may develop into ‘la marked cord-like swelling throughout their course reaching a width ,5 of as much as one-half inch at the base and exhibiting a deep livid red f color before pustules may appear thereon. In other cases the swelling is rather difiuse and may reach a thickness of one-half inch. The pus- 3tules develop, not only along the line of scarification, but also appear adjacent thereto or indeed some distance removed therefrom. The location of the development of the primary pustules thus shows that while the entrance of the virus has undoubtedly been aided by a ght rupture in continuity of the epidermis in the form of a scarifi- =cation, yet the development of secondary pustules extends beyond such lrtal of entry to the apparently unbroken skin. It is beyond the scope this publication to discuss the problem whether the virus traveled to y - location of the new lesions through the tissue or whether it has found i portal of entry through the apparently unbroken epidermis, but our ob- lrvations indicate that its entry through the apparently unbroken epi- ifirmis is entirely possible. The gross appearance and the manner of de- llopment of the lesions to this stage resemble those observed in the vac- A‘ -variola group of disease. 3 The pustules do not all develop simultaneously but new vesicles and Istules may appear from day to day for a week or longer so that all f». :ges of development may be seen side by side. During this time not A_ y the tract of _the scarification may become closely studded with pus- . es but they may also develop some distance removed therefrom so that Vthe end we may have a broad band of irregularly placed pustules of L b r 5.- E l0 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION which the original scarification approximately forms the middle line. But long before the last pustules have developed, those formed first will have ruptured either spontaneously or from mechancial interference and have scabbed over. It is most likey that the virus escaping from such ruptured pustules is to a greater or less degree spread to adjoining parts of the skin and contributes largely to the development of additional pustules. Thus, it has been repeatedly observed by us that if the original scarification and inoculation was made on the under surface of the tail in goats after the first pustules had ruptured at the original point of inoculation, new pus- tules would soon thereafter appear on the skin below the anus. or vulva at a point far removed from the original site of inoculation but nevertheless subject to being soiled with the escaping content of the pustules. When the thin glistening layer of epidermis over the pustules breaks and the contents escape, a lesion is formed in which the more vital layer of the skin is exposed and is now subject to secondary infection, particu- larly by pus organisms which are found everywhere in great abundance. As a rule, however, the content of the ruptured pustules, so far as it is not mechanically removed, and the cell debris, augmented by additional purulent material oozing from the exposed dermis, gradually dry up and form a scab. Naturally the injury set by the virus which led to the for- mation of the pustules is not repaired with the rupture of the latter, but rather the reaction in the skin will continue until normal conditions are again restored. During the duration of this reaction we will find that the natural protective forces of the body, the polynuclear leucocytes and kin- dred cells in addition to excessive amounts of serum have been concen- trated at the site of attack of the virus and now force their way to the surface acting as scavengers of the polluted area. As they continue to arrive at the surface of the still viable tissue and beneath the already formed scab, they in turn will also become dry and continue to add to the increasing thickness of the latter. In addition, to these changes the Malphigan layer of the skin will begin to proliferate, thus forming ex- cessively heavy layers of epithelia which dry out and also add continually to the thickness of the scab; the dermis itself becomes thickened, hyper- trophic, and thus raised several millimeters above the general level of the surrounding skin. This becomes particularly apparent when one forcibly removes some of the dry scabs, for one will find under them a raw, bleeding surface ‘markedly elevated over the adjoining healthy skin. The development of the lesions thus have, in the acute stage, all the char- acteristics of a suppurating dermatitis. At times pus may be found to ooze or may be expressed from under the scabs. In many instances the development of individual papules can not be observed along the line of scarification. In such cases the line of scari- fication as a whole or parts thereof shows, on the third or fourth day, in- creased redness and slight swelling. Both of these manifestations in- crease in intensity from day to day so that the scarifications soon stand out prominently as deeply bluish-red ridges along which no indication of pustule formation or suppuration can be detected. As these reddened SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 11 prominent ridges increase in thickness they also increase in width, some- times attaining a width of one-half inch. At the end of a week or ten days the surface of these ridges begins to get dry and hard, thus usher- ing in the scab formation. Scab formation as just detailed is often rather prolific. The scabs or crusts may reach a thickness of one-half inch or more remaining confined, of course, to areas near the site of infection or to which the virus spread by con- tact with the contents from the ruptured pustules. They are dry, hard, brown to dark-brown, tightly adherent to the under- lying tissue and when forcibly removed leave a raw, elevated, bleeding surface. As time goes on they become cracked and fis- sured on the surface, from which they gradually crumble away until, at the end of three or four weeks or more, they have Fig. 1. Scab formation on lips in kid following entnjely dlsappeared Wlthout artificial transmission. leaving a SO31‘. The lesions following artificial transmission as described are those ob- served in a fairly marked reaction. In many instances, however, much milder lesions will be observed following such inoculation and these vary somewhat in their appearance from animal to animal. In many in- stances only papules that did not progress into the vesicle or pustule stage were observed. These papules appear in the skin on the inoculated area as hard knots two to three millimeters in, diameter, project hemi- spherically above the surface of the surrounding skin, and later become covered with a thin, dry, brownish scab. This thin scab finally drops off and the knots gradually disappear in the course of the next few weeks. In another type of lesion we have observed a reddening of the skin at the point of inoculation and more or less pustule-formation, but the scab forming over such pustules remained very thin and had a tendency later to peel off as a whole instead of becoming crumbly, as happens in cases where the scab reaches an appreciable thickness. In a third type of light lesion observed the scabs forming after the appearance of pustules would become one or more millimeters thick, would always be dry with no indication of pus-formation under them, remain gray in color, adhere tightly to the somewhat thickened skin, and have a scaly appearance. These scales gradually drop away from the surface as healing progresses. Lesions on the mucous membrane of the mouth have been less fre- quently observed by us. In the mouth the ulcerous lesions developing at the point of infection are constantly kept moist so that the exudate from them and the proliferating epithelial cells have no opportunity to become 12 BULLETIN NO. 451, TEXAS AGRICULTURAL EXPERIMENT STATION desiccated but instead remain soft and moist and are constantly being more or less completely removed by the necessary movements of the tongue and other mouth parts against one another while the animal is eating or drinking. The lesions, therefore, show no scab formation but on a red- dened mucous membrane there appears a somewhat elevated, creamy, whitish-yellow, spongy, membranous deposit. The tissue underlying such deposits bleeds very readily when it is touched. These lesions can be pro- duced on the mucosa by inoculation similarly as on, the skin. It is significant that in all our transmission experiments where the site of inoculation was either the internal aspect of the thigh or the under surface of the tail, the lesions remained localized to such point of inocu- lation. In no case did-lesions develop on the lips. TRANSMISSION OF THE DISEASE Experiments to determine the nature of the disease were first under- taken by us in September, 1928. It could readily be shown that the dis- ease was infectious. The first attempt to transmit the disease by scari- fication of the lips of lambs and by applying emulsions made from fresh- ly collected scabs were successful in reproducing the disease. Such arti- ficial transmission of the disease has since been repeated on numerous oc- casions. In one instance soremouth was also produced by scarifying the lips of a lamb by pricks with a cactus thorn and vigorously rubbing into it dirt from the floor of a sheep stall in which soremouth cases had been kept. From this, one might infer that the virus might also be found in pastures where the infective material has dropped from the animal and there constitutes a source of infection for other animals as they graze over such areas. How long the virus may remain alive in the soil and litter of sheep sheds has not been established. It is known that out- breaks of soremouth do not appear on the same premises year after year but sometimes a year or more may intervene between outbreaks. Whether in such cases the virus had died out and was later re-introduced from an outside source is not known. However the fact that the disease does not appear in any one year on infected premises does not mean that such premises are permanently free from the disease. In our experiments, as will be seen from Table 1, the area to be inocu- lated was scarified in every instance. That lesions can also develop on unscarified areas has already been pointed out. In view of the latter ob- servation it must be considered doubtful whether sheep or goats in order to become infected must first injure their lips on coarse feed or otherwise before infection can take place. That such injury to the lips might aid infection in establishing itself is quite plausible. Our attempts to transmit the disease to guinea pigs have been unsuc- cessful. That other investigators have failed to transmit the disease to other animals has already been recorded. It may be pointed out in this connection that the disease has neverbeen observed in cattle, although they have frequently come in close contact with infected sheep or goats. References are contained in the literature (3, 4) to the effect that lesions SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 13 resembling soremouth have been observed in persons coming in close con- tact with the disease in sheep. We have observed two similar instances, but as yet have no definite proof that such lesions were due to soremouth virus affecting sheep or goats. Table 1. Experimental transmission of soremouth; point of inoculation scarified. Date Number of Source of Virus Site of Result animal inoculation 9/15/28 Lamb 17 Dirt from sheep shed Lips Soremouth Lamb 18 Scabs Lips Soremouth; raw, bleeding ulcers and false mem- branes also on mucosa. of lips. Lamb 19 Scabs Soremouth; raw, bleeding ulcers and false mem- branes also on mucosa of lips 10/ 1/28 Lamb 26 Scabs from N0. 17 Lips Negative Lamb 27 Scabs from No. 18 Lips Negative Lamb 28 Scabs from No. 19 Lips Negative 11/22/28 Lambs 16, 17, 18, 19, 20, 30, 31 Dirt from sheep shed Lips Negative 12/24/28 Lambs 67, 68, 69 Scabs Lips Soremouth 1/ 3/29 Kid 76 . Lambs 77, 79, 80 Virus No. 68 Lips Soremouth 3/ 2/29 Ewe 294 Scabs Lips Mild soremouth Ewe 295 Scabs Lips Severe soremouth 5/ 2/29 Kid 969 Virus No. 967 Lips Soremouth Nanny 970 Virus No. 967 Lips Soremouth _ Nanny 977 Not inoculated, nurs- Developed soremouth le- ing No. 969 sions on teats 5/ 2/29 Guinea pig 971 Virus No. 967 Lips Negative 5/16/29 Guinea pig 1030 Virus No. 969 Lips Negative Guinea pig 1031 Virus No. 969 Lips Negative Guinea pig 1032 Virus No. 969 Lips Negative 5/20/29 Kid 1057 Virus N0. 969 Lips Soremouth Nanny 1058 Not inoculated, nurs- Lips Developed soremouth le- ing No. 1057 sions on teats 4/25/29 Goat 1 Sheep Lips Light scab formation Goat 2 Sheep Inguinal region Marked scab formation 5/22/29 Goat 3 Goat Inguinal region Marked scab formation 6/15/29 Kid 4 Unknown Inguinal region Marked scab formation Kid 5 Unknown Under tail Doubtful Kid 6 Unknown Under tail Light scab formation Kid 7 Unknown Under tail Doubtful 9/ 13/29 Kid 4 (retest) Unknown Inguinal region Marked scab formation Kid 8 Unknown Inguinal region Marked scab formation DIFFERENT STRAINS OF VIRUS The question whether one strain of virus must be recognized for the sheep and one for the goat has not yet been-decided. We were able to transmit the sheep virus obtained from natural cases of soremouth in the sheep to goats and vice versa but believe to have observed a much milder development of the disease in the sheep" when goat virus was used and l4 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION vice versa. Table 2 shows the reactions obtained in sheep when inoculated with fresh goat virus. Table 2. Susceptibility of sheep to goat virus. Sheep inoculated Nov. 20, 1931 with fresh goat virus in inguinal region after scarification. Animal Reaction number 11/25 l 11/27 \ 11/29 I 12/4 1 Doubtful Many pustules Pustules and scabs Pustules dried up but no brown scabs formed 2 Red Doubtful Doubtful Doubtful 3 Pustules 11 pustules Meager scab forma- Scabs dropping off tion 4 Red Pustules Meager scab forma- Scabs dropping off tion 462 I Pustules 3 pustules Mriager scab forma- Scabs dropping off ion 463 Red Pustules and scabs Meager scab forma- Scabs dropping off tion Although numerous pustules were formed in two of the six sheep inocu- lated, yet in the animal showing the most numerous pustules they dried up without leaving a dry, brown scab; and in the animal showing the next largest number of pustules the thin scabs formed were already dropping off nine days after the appearance of the pustules. When such a marked pustule formation took place in the goats from which_ the virus used to inoculate these sheep was taken a very heavy scab formation always re- sulted, which in all probability would not have cleaned up in less than three or four weeks. Field. observations by us also indicate the existance of two different strains of virus and a similar observation is recorded in the literature (4), although not so interpreted. Jacotot (1), although he does not cite any evidence, is of the opinion that sheep appear more re- sistant to infection than goats. We expect to continue our researches regarding this point. SUSCEPTIBILITY OF ANIMALS On the range where the disease is endemic, outbreaks in flocks are usually limited to the young animals up to a year old. Of these it is estimated that as many as 90% to 95% may develop more or less marked readily recognizable lesions on the lips. In our experiments with young goats we observed a marked variability in the “take” of the disease which could not be explained on the basis of insufficient ex- posure or a variability in the virulence of the virus. We believe that our technic of inoculation, consisting of a scarification of the skin and vig- orously applying an emulsion of relatively fresh triturated soremouth scabs, subjects the animal to as severe an exposure to the infection as it may encounter in the field, and yet we were not able to reproduce the dis- ease in every case. We always inoculated at least two animals at the same time with the same virus and sometimes found only one of the two SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 15 to develop the disease. Moreover we found animals that failed to de- velop the disease even after a number of inoculations. As an example we cite kids Nos. 413, 431, and 450 shown in Table 3. One of these kids, No. 431, resisted infection in three inoculations, and two, Nos. 413 and 450, in two inoculations; while all other animals (five or more) in the same experiment developed the disease. This finding suggests that some animals may possess a natural immunity and would explain why not all young animals in a flock contract the disease. Table 3. Showing resistance of some animals to (artificial) inoculation. _ Date inoculated, 1931. Kld NO- s—s 10-1 l 11-20 — — 11 papules about 2 mm. in diameter 413 431 - _ - 450 Controls I -1- -l- -l— It is only seldom that gross lesions are seen in older animals on the range but on several occasions such were found upon closer examination of apparently clean animals. Information is not available whether these animals had a previous attack of the disease or whether they had been exposed and escaped infection or had never come in contact with the dis- ease. In order to secure some information on the susceptibility of aged animals, experiments were undertaken on aged goats outside of the en- demic area on animals that had been raised on the experimental grounds and were known never to have been exposed to the virus. The results of these tests are shown in Tables 4 and 5. Of the 26 animals inoculated 12 showed a marked positive reaction, 10 a doubtful to mild reaction, and 4 showed no reaction. Since all of these animals were inoculated with freshly collected virus the results clearly indicate that there is a marked variation in the susceptibility of older animals. Table 4. Susceptibility of aged goats to soremouth. Inoculated Oct. 1, 1931 with goat soremouth virus by scarification of skin on under surface of tail. No. of | Dates of examination (1931) and results. animal l 10/5 l 10/7 l 10/8 l 10/9 l 10/10 10/17 l 10/24 418 -— — — — — — -— 434 — — — —- — — — 452 -— —-— — —l— ‘I 3 papules 3 papules Clean 453 —- + + + + + + + + Clean 355 + ? + ++ ++ ++ ++ Clean 455 — — + + + ++ ++ g1%%n31 FILTRATION EXPERIMENTS After we had clearly established the infectiousness of soremouth we began to cast about for the probable cause. Our observations of the na- ture and development of the lesions let it appear likely that the cause of the disease is not an ordinary bacillus and would likely be very diffi- 1 cult to isolate. Indeed the literature appearing in the meantime sub- BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION .2052 wovimfi .25 no 00.3.25 .335 no Ex» mo compwuflmawum an ma? saaofiwnow 3.8M at? 32 .3 .000 000010005 iwnofivaoom o0 $.80 wwws mo aumifianoomflw d. 030m. I503“ + + u mflomwm; was“ IT u Euunsofluw + u oZuwNoZH l u ucwcinomxw 59G wmmwwfl-NHQ 393mm .520 05.520 + + + + + + + + + l w 3v 3x230 .820 Ivm + + + + + H + H + + w mm“ l l l . l l 0.23230 .520 + + + + + + + + + + + I w w? 382mm E86 M5586 + + + + + + + + + + l w S“. c0505 m l l M. + N. + l I l 5x05 3% M l l l 0 + + l l w u: wwmfiiwfi .536 M5520 ++ + + ++ +.I+_| + I M. W “WW ml I I . I I . w Ml l l T. l l l ~. l w m2 Ml l IT N. + l l l w N? ml I + + + + I w o? wowmfiwfl . -536 M5586 + + + + + H + 0w .._.T 0. + N + “aim ww 2w m I I . . I I w? M l l l N. l A. + l l w v3 ml I I + N. + I I w N3 wowaflofi .3505 -536 M5536 + + + + + T41. 0A.. + 0. + N. H zméopw 5v M l l . . l l . $0. M22066 ++ Lm+ ++ T? L? ++ + _.I 22a w a“ mQ: A 3E , ma: _ 0Q: _ HQ: $2 _ t: 3: _ Q: 0mm i 125:0 315mm did A320 Gomudcihwxw we 30G swoon. mo .02 SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 17 stantiated our belief and contained reports of the filterability of the virus. In order to more definitely establish the identity of soremouth as observed by us with the disease described as contagious ecthyma, etc., filtration experiments were undertaken. Six experiments were run, three using the Mandler diatomaceous filter and three using the Seitz asbestos filter. In each case scabs recently collected and preserved dry in the dark were finely ground in a sterile mortar. Physiological salt solution was then added and the grinding continued about 5 minutes longer. This emulsion was then diluted with physiological salt solution to give a dilution of about one to fifty on the basis of dry scabs used. One portion of the emulsion was then passed through a Seitz filter and another portion through a Mandler filter. Filtration was started within an hour after the emulsion had been prepared. In each case the unfiltered residue of the Mandler filter was used to inoculate the control animals. Filtration through the Seitz filter was accomplished under pressure and required only a few minutes. Filtration through the Mandler filter was by suc- k. tion, and required about thirty minutes. Only enough material was passed through the respective filters to suffice for the inoculation of three ani- mals from each. Inoculation of the animals was undertaken within an ~ hour after the completion of the filtration with the exception of Experi- ment 1, in which case the filtrates together with the residue for the inocu- lation of the control animals was kept in a refrigerator for 24 hours. Three animals were inoculated on the under surface of the tail after scarification from each of the two filtrates, while 4 animals were inoculated in a similar manner with the residue. The results are recorded in Table 6. Table 6. Filtration experiments. Animal Date number 1931 Mandler Filterl Seitz Filter l Controls First experiment 419 6-12 — 431 " - 413 ” as no -a Ill 7-21 i O5 ++++ ++++ ++++ ++++ ++++ + ++++ + I‘ ‘Only control animals are listed in 2nd and 3rd experiment. To test filterability of virus the same animals were used as in Experiment No. 1 Since none of the animals inoculated from the filtrate developed lesions of soremouth, the same animals were inoculated from the same kind of 18 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION filtrate in the next succeeding filtration experiment while 4 new controls were used. After the completion of these experiments, the animals inocu- lated with the filtrates were inoculated with unfiltered virus to test their susceptibility to soremouth. In each instance only two of the three animals used for each of the two kinds of filtrate developed well- marked lesions while the third animal in each group, already refer- red to in our previous discussion as No. 413 from the Seitz filtrate and No. 431 from the Mandler filtrate, failed to develop lesions. Since these two animals resisted two later inoculations with known potent virus, the possibility arises that they might have contracted an immunity Without the development of grossly recognizable lesions. The results of the other two animals in each experiment would indicate, how- ever, that this is not the case. We expect to investigate this point further. The results of our filtration experiments were thus all negative. In view of the results from similar filtration experiments recently recorded in the literature this outcome was not surprising and can only be interpreted as emphasizing the findings of others that the virus is at least very diffi- cult to filter. Additional experiments will be undertaken to determine whether our results can be brought into complete agreement with those of others. IMMUNITY TESTS The question of immunity in soremouth has interested us from the time we were able to show that the disease is infectious. The ‘fact that from a practical standpoint only young animals contract the disease on the range and that the mother animals usually remain free from lesions, although they are in close association with their nursing young, already suggests that an immunity develops. Since the disease itself is one of the skin, any immunity established is likely an immunity of that organ, which would develop regardless of the point of infection. With this possi- bility in mind we sought to transfer the development of the lesion from the lips to a point where it would not interfere with nursing or prehension of food and water. The most desirable place to set the lesion is, of course, one devoid of hair or wool, such as the under surface of the tail or the internal aspect of the thigh. For the purpose of establishing an immunity, either would be satisfactory. Our first experiments to test the practicability of establishing such an immunity were run in 1929. The outcome of these were not very satis- factory. Further work on this point was postponed until 1931, when more extensive tests were undertaken. The results of these tests are recorded in Table 7. The duration of the immunity following artificial inoculation has not been followed in our animals over a very long time largely because it was impractical for us to hold them over an extended period for such tests. That immunity does not always follow the first inoculation even though fairly marked lesions are established is shown by animal 4, Table 1, and animals 407 and 451, Table 7. Animal 4 waschecked only SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 19 once three months after the original inoculation while animals 407 and 451 were checked twice, the first time 41 days and 45 days re- spectively after the original inoculation. All three A animals again showed well developed lesions upon the first check but when animals 407 and 451 were again checked 89 and 58 days after the first im- munity test they did not again react. Table 7. Immunity test for soremouth on goats; inoculated on under surface of tail after scarification. Date of first Inoculation for immunity test Kid No. inoculation, 1931 Date, 1931 \ Reaction 407 5»-22 7- 3 + 4071‘ 7—— 3 10—- 1 411 6- 2 " _ 419 8—— 3 ” — 42s 7_21 " - 425 7-21 " - 427 8—— 3 ” — 433 8—— 3 ” -— 435 7—21 ” -— 437 7— 3 ” — 439 8- 3 ” - 445 7——21 ” - 446 7_ 3 _ 447 7~— 3 ” — 451 6—-19 8— 3 + 451T s— s 10~ 1 - Controls for final test 413* 10— 1 — 415 ” + 417 ” + 42O ” + 429 ” + 431‘ ” —— 441 ” + 448 ” + 450* ” -—- "‘Regarding reaction of these three animals see also Table 3. tThese are second trial with the same animals. Encouraged by these results we decided to undertake a field test. The ranch selected was one on which both sheep and goats were kept and on which soremouth had occurred among the goats but not among the sheep during the previous year. Two hundred lambs and 77 kids were inoculated on the under surface of the tail with goat soremouth virus and conspicuously marked for proper identification; three hundred lambs and 70 kids were left for controls. The lesions developing among the inoculated animals were not checked for severity. Some three weeks later the uninoculated control kids began to show soremouth lesions on the lips, and by the 26th day it was estimated that 80% of the control kids showed such lesions, some of them so severe that the owner found it necessary to treat them. No soremouth occurred among the lambs left as controls. The owner of these animals was very much encouraged by the outcome of the test and as the result of it we have inoculated a large number of lambs during the present season with the view of restricting the lesions to a part of the body Where they do not interfere with the taking of nourishment and where they can be set early 20 BULLETIN NO. 457, TEXAS AGRICTJLTURAL EXPERIMENT STATION enough in the season before the screw-worm fly becomes active. In this way we expect to greatly reduce the losses from soremouth. As this manuscript goes to press, results of these vaccination, experiments also indicate that vaccination is highly successful. Much work remains to be done on the degree of immunity developed following‘ artificial inoculation, especially on the degree of the visible gross reaction necessary to establish an immunity that will stand up in the field. We have especially in mind to determine whether the mild types of lesions described as sometimes following artificial inocu- lation will establish a satisfactory immunity or not. This whole question is, of course, closely bound up with the virulence of the virus, the pro- duction of a suitable virus properly attenuated for use in the field, the susceptibility of the animal, and cross immunity between strains of virus developing on sheep and goats. TREATMENT Medical treatment for soremouth at its best is unsatisfactory. This is to be expected from the nature of the disease. The destruction of the virus would be the logical thing to strive for, but by the time lesions are observed the greater part of the virus is already located within the skin out of reach of any medical treatment applied to the surface. If the owner wishes to apply a germicide at this time, one that has deeply penetrating powers should be selected such as tincture of iodine or an alcoholic solution _ of gentian violet. The germicidal power of pine tar may also be utilized and is best diluted with some oil. For this purpose used crankcase oil may be taken in the proportion of one part pine tar and two parts oil. This preparation may also be used later when scab formation has already set in. It has a tendency to soften the scabs and thus keep the lips more pliable. A better preparation for this purpose is a mixture of one part of tincture of iodine to two parts of glycerine. Other bland fatty or oily substances to which some non-irritating antiseptic has been added serve the same purpose. Repeated applications of the selected treatment are indicated. SUMMARY Soremouth (Contagious Ecthyma) of sheep and goats is very prevalent in the sheep- and goat-raising area in western Texas, and is also found in other states of the Union as well as over large areas in other sheep- raising countries. The disease can readily be transmitted by emulsions made from the dry scabs formed as a result of the infection when applied to the scarified skin. The course of the disease with its attendant lesions is described. The disease is most prevalent among young animals up to one year of age but a large percentage of much older animals can be readily infected artificially. The mortality from the disease is very low but SOREMOUTH (CONTAGIOUS ECTHYMA) IN SHEEP AND GOATS 21 indirect losses resulting from screw-worm infestation, stunting of young animals, and feed-lot shrinkage may be very high. The nature of the virus has not yet been determined. Some investi- gators report that they succeeded with difficulty in filtering the virus through various bacterial filters. We failed in three attempts to pass the virus through Mandler and through Seitz asbestos filters. The disease can be transmitted from sheep to goats and from goats to sheep but the goat virus does not appear to be as virulent for the sheep as sheep virus and vice versa. This points to the existence of a sheep virus and a goat virus. In our experiments recovery from the disease left a high degree of immunity, the maximum duration of which is still unknown. Whether a cross immunity exists between the possible sheep and goat strains of virus has not yet been determined. Although on the range the lips are the principal site of the lesions, nevertheless they occasionally also ap- pear on other parts of the skin and can be produced artificially on any part of the skin, where they will remain localized. We are taking advantage of this fact and expect to test out the practicability of immunizing the it young animal on some part of the body other than the lips before ‘7 screw-worm time arrives in the spring. BIBLIOGRAPHY »_ .- (1) Jacotot, H. L’ecthyma contagieux des levres chez la chevre en Annam. Rec. de Med. Veter. Vol. 100, 1924, 270. Cited from abstract in Tropical Veter. Bul. Vol. 12, 1924, 108. Theiler, A. Ecthyma Contagiosum of Sheep and Goats. 13th and 14th Reports of the Director of Veter. Education and Research, Part 1, 1928, 9. Willems, R. L’ecthyma contagieux des levres du mouton. Ann. de. med. veter. Novembre 1929. 454. Hatziolos, M. Observations sur une epizootie d’ecthyma contagieux des levres. Revue gen de med. veter. Tome XXXIX, 1930, 263. Seddon, H. R. Scabby Mouth in Sheep and Goats. Agricultural Gazette, N. S. Wales, Vol. 41, 1930, 447. Newsom, I. E., and Cross, F. Some Complications of Soremouth in Lambs. Jour. Amer. Vet. Med. Ass’n, N. S. Vol. 31, 1931, 539. Howarth, J. A. Infectious Pustular Dermatitis of Sheep and Goats. Jour. Amer. Vet. Med. Ass’n, N. S. Vol. 18, 1929, 741. Carre, M. Some Diseases of Sheep. (Translated title). Rec. de Med. Veter. Vol. 107, No. 11. Cited from Abstract in Veter. Record. Vol. XII, 1932, 225. Miegeville, M. Le pseudo-ecthyma contagieux des levres du mouton et de la chevre et la stomatite contagieuse des agneaux et des chevreaux au Maroc. Rev. Veter. et Jour. de Med. Veter. et de Zootechnie Reunis. Tome LXXIX, 1927. p. 313. 22 BULLETIN NO. 457, TEXAS AGRICULTURAL EXPERIMENT STATION (10) Hutyra-—Marek. Specielle Pathologie und Therapie der Haustiere, Vol. 3, (1922), p. 591. Gustav Fischer, Jena. (11) Oppermann, Th. Lebrbuch der Krankheiten des Schafes. 1929, p. 91. M. & H. Schaper, Hannover. (12) Glover, R. E. Contagious pustular Dermatitis of the Sheep. The Jour. of Comp. Path. and Therapeutics. Vol. XLI, 1928, p. 318. (13) Melanidi, G., et Stylianopoulo, M. L’ecthyma contagieux du mouton en Grece. Revue gen. de Med. Veter. October 1928. Cited from abstract in Revue Veter. et Jour. de Med. Veter. et de Zoo- technie Reunis. Tome LXXXI, 1929, p. 215. (14) Melvin, A. D., and Mohler, J. R. Lip-and-leg Ulceration of Sheep. U. S. D. A., B. A. I. Circular 160, 1910. (15) Jacotot, H. L’ecthyma contagieux des levres en Annam. Ann. de 1’Inst. Pasteur, 1926. Tome XL. p. 49. Cited from Glover (12).