THB; MORMAL h i s t o l o g y AHL HEHATOLOGY o f THÜ TURKEY AND THK PATHOLOGY DUE TO HISTQKOHAS MELEAGRIDIS By Thomas Donald Malewitz A THÉÜSIS Submitted to the Schoolfci Advanced Graduate Studies of Kichi&an State University of Agriculture and Applied Science in partiar fulfillment of the requirements for the degree of DOCTOR OP PHILOSOPHY Department of Anatomy 1956 ProQuest Number: 10008664 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10008664 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346 Michigan State University ABSTRACT The normal histology of the lungs, heart, kidney, pan­ creas, spleen, liver, and intestinal tract of turkey poults was studied, and found to be similar to the chicken. tha t cf Fibro cartilage was observea in uhe ascending aorta of the heart. The large Purkinje fibers appeared to follow the vasa vasorum. Esophageal glands opened into the crypts of tonsil-like lymph nodules near the junction be­ tween the esophagus and proventriculus• The muscularis mucosa, when present, consisted of only one circular layer of smooth muscle. Elastic fibers were observed in the con­ nective tissue stroma separating the parabronchi of the lung. The normal hematology of turkeys was studied and com­ pared with the results of other investigators. Twelve turkeys were orally inoculated with embryonatedHeterakis galliriae ova to produce a histomonas infection. Seven turkeys expired from the disease, one recovered, and four showed no symptoms of infection. Blood studies re­ vealed a decrease in the total red blood cell count, hemo­ globin, and white blood cell count. The heterophils in­ creased while the lymphocytes decreased. Monocytes, eosinophils and basophils remained within a normal range. The temperature rose during the infection and was sub-normal at the time of death. li Typical gross lesions produced by Histomonas meleagridie were observed in the liver and ceca of the eight infected turkeys. Gross lesions were also observed in the spleen, kidney 3 and lungs. Microscopic lesions, in which the parasite could be demonstrated, were observed in the ceca, liver, kidney? and spleen. These lesions were characterized by hyperemia, hemorrhage, lymphocytic infiltration, presence of giant cells, necrosis, and usually a serous exudate. The lung, pancreas, and heart exhibited lesions characterized by hy­ peremia and a sero-cellular exudate. tration was observed in the lungs. Lymphocytic infil­ Parasites were not demonstrated in the lung, pancreas or heart. ill A G O OWIEDGMEHTS The author is deeply grateful to Dr. M. Lois Calhoun, Professor and Head of the Department of Anatomy, for her constant stimulation, patience and guidance during this in­ vestigation and the preparation of this manuscript. The writer wishes to express his thanks to Dr. J. Frederick Smithcors, Department of Anatomy, for giving so freely of his time and his many helpful suggestions regarding this manuscript. Many thanks to Dr. Esther M. Smith, Department of Anatomy, for her valuable assistance in the preparation of the photomicrographs. Sincere appreciation is extended to Dr. H. J. Stafseth, Professor and Head of the Department of Microbiology, for his efforts and constructive criticism of this manuscript. The author expresses his thanks to Dr. William D. Lindquist, Professor and Head of the Parasitology Section, for the use of equipment, and checking microscope sections. Thanks are also extended to Dr. R. F. Langham, Depart­ ment of Animal Pathology, for his suggestions regarding the microscopic sections and the manuscript. The author is grateful to Dr. R. A. Runnells, Resident Consultant Pathologist, Upjohn Co., Kalamazoo, Michigan, for his helpful suggestions regarding the microscopic lesions reported in this study. iv Many thanks to Miss Frances M. MarteXli, Secretary to the Dean of the College of Veterinary Medicine, for trans­ lating the many Italian articles; to Miss Ada Beister, reference librarian, for obtaining the interlibrary loans; t Mrs. K. Felch, and other technical assistants, for their assistance in this work. VITA Thomas Donald Malewitz candidate for the degree of Doctor of Philosophy Final examination: Giltner Hall Dissertation: 10:00a.m., May 24, 1956, Room 101, The Normal Histology and Hematology of the Turkey and the Pathology due to Histomonas meleagridis Outline of Studies Major subject: Minor subjects: Anatomy Pathology and Microbiology Biographical Items Born: April 13, 1929, Holland, Michigan Undergraduate Studies: Hope College, Holland, Michi­ gan, 1947-1951, B.A., 1951 Graduate Studies : University of Kansas, Lawrence, Kansas, 1951-1953, M # A . , 1953 Experience: Assistant Instructor in Biology at the University of Kansas, Lawrence, Kansas, 19521953; Graduate Assistant in the Department of Anatomy, Michigan State University, East Lansing, Michigan, 1955-1956 Member: the Society of Sigma Xi; Phi Sigma, Ameri­ can Association for the Advancement of Science; American Society of Parasitologists; American Society of Protozoologists vi TABLE OF CONTENTS Page I N T R O D U C T I O N ............... 1 REVIEW OF L I T E R A T U R E ........................... 2 MATERIALS AND M E T H O D S .......... 12 RESULTS AND D I S C U S S I O N ........................ 17 Gross A n a t o m y ............................. 17 Normal Histology of Turkeys • • • • • • • « . 35 Esophagus................................. 35 C r o p .............................. .... 36 • Junction Between Esophagus and Proventr 1cuius........................... Proventriculus 38 . . . . . . . . . . 41 Junction Between Proventriculus and Gizzard. ....................... 44 Gizzard. 49 ....................... Junction Between Gizzard and Duodenum. • ............... Small Intestine. 52 53 Cecum. 56 Rectum .......... 59 Bur 3 a Cloacae.......... 59 Liver. . . . . . . 62 Pancreas . . . . .................... . . . . . . . S p l e e n ................................ 05 65 Kidney ................................... 70 L u n g ........... .......................... 71 \ vii Page H e a r t ............. 7i Normal Hematology of Turkeys . . . . . . 87 Symptoms Due to Histomonas Meleagridis . . . . 90 Hematology of Infected Turkeys................. 95 Gross Pathology............... .. ............... 103 Microscopic Pathology. 110 . .. . . . . . . . C e c u m .............................. Liver . 110 ... L u n g ............. Ki dney.............................. 115 110 124 Spleen.......... 124 Pancreas.......... 124 H e a r t ......................... ........... 124 S U M M A R Y .............................................. LITERATURE CITED .............................. V I 11 138 136 LIST OP PLATES PLATE I. Page Digestive tract of turkey poult ............. 20 II. Mouth parts of the turkey . . . . . . . . . 22 III* Junction between esophagus and proven­ triculus....................................... 24 Pr oventriculus................................ 26 V. Junction between proveniriculus and gizzard • 26 VI. Junction between gizzard and duodenum . . . . 30 ................. * 32 Folds of bursa c l o a c a ........................ 34 E s o p h a g u s ....................... 37 Junction between esophagus and proveniricuius 40 XI. Duct of esophageal gland..................... 43 XII. Provenir 1 cuius................................ 46 XIII. Elastic fibers in the muscularis externa of the proveniriculus............................ 48 XIV. G i z z a r d ....................................... 51 XV. Small i n t e s t i n e .............................. 55 XVI. C e c u m ......................................... 56 XVII. Bursa c l o a c a e ................................ 61 ....................................... 64 IV. VII. VIII. IX* X* XVIII. XIX. Villi in duodenum Liver Pancreas.............. 67 XX. Spleen......................................... 69 XXI. Kidney......................................... XXII. Duct of Bellini in the k i d n e y ............... IX 76 PLATE XXIII. XXIV. XXV. XXVI. XXVII. XXVIII. XXIX. XXX. XXXI. XXXII. Page L u n g .................................... 76 Elastic fibers in l u n g ................. 80 Purkinje fibers in e n d o c a r d i u m ......... 82 Purkinje fibers around a vasa vasorum. ... 84 Fibrous cartilage in the aorta . . . . . . . 88 Weight changes . . . . . . . ......... Tempera-ture v a r i a t i o n s .................. 95 94 Red blood cell c o u n t .......... 98 Hemoglobin determinations................ 99 White blood cell count ..................... XXXIII. Heterophil and lymphocyte count......... XXXIV. Monocyte, eosinophil and basophil count. XXXV. • 100 101 •. Gross cecal lesions.............. 106 XXXVI. Gross liver lesions...................... 106 XXXVII. Necrosis or cecum........................ 112 XXXVIII. XXXIX. XL. XLI. XLII. Giant cells and protozoa in cecum. . . . . . xl4 Necrosis ©f r iver................ Giant cells and protozoa in liver. 102 117 • . . • • Parabronchial edema...................... 119 121 Heterophils and macrophages in exudate of lung 123 XLIII. Giant cells and protozoa in kidney . . . . XLIV. Giant cells and protozoa in spleen . . . . . 128 XLV. Protozoa in blood vessel of spleen ......... 130 XLVI. XLVII. . 126 Inflammation of mesentary around pancreas. . 132 Epicarditis.......... 134 L IS T OF TABLiÜS Page Table 1 Comparison of the Normal Blood Picture in Turkeys ......................... 2 Weights and Measurements of Turkey Organs • • XI 10^ INTRODÜCT ION Enterohepatitis, histomoniasis or blackhead, a common disease of turkeys, was first observed by Cushman in 1892* Since this time numerous investigations concerning the eti­ ological agent, mode of transmission, pathology, treatment and prevention of blackhead in turkeys have been reported* The objectives of this study were concerned with the lesions produced by Histomonas meleagridis in the various organs of the turkey and the accompanying changes in the blood count. The shift in the total blood count and dif­ ferential count was correlated with the progress of the in­ fection* There have been few observations reported in the literature on the normal histology and hematology of the turkey* Therefore, the normal histology of the lungs, heart, kidney, pancreas, spleen, liver, intestinal tract, and blood was studied along with the pathological changes caused by H. meleagridis. REVIEW OF LITERATURE Due to its economic importance, enterohepatitis in turkeys has been the subject of numerous reports. Black­ head has also been reported in chickens, wild turkeys, quail, pheasants, pigeons, ducks and geese. The distri­ bution of this disease is world wide. Chester and Robin (1900J and Eveleth (1943) reported enterohepatitis in chickens. Prominent symptoms were not observed, but typical lesions of the liver and ceca were present. Smith and Graybill (1920) noted that chickens usually recover from histomoniasis. Rectal injection of H. meleagridis in young chickens resulted in infections (Tyzzer 1924, Bishop 1938), but recovery followed. Lower mortality in chickens than in turkeys infected with H. meleagridis was observed by Eriksen (1925). Rettger et a l . (1929) stated that chickens are more dangerous as carriers of H. meleagridis than turkeys. According to Baker (1933), histomoniasis resulted in retarded development of chickens. Excessive development of H. meleagridis rendered conditions unsuitable for the growth of H. gallinae. Enterohepatitis has also been reported in wild turkeys by Van Roekel (1929) and Kozicky (1948). Wenrich (1943) described the morphol­ ogy of H. meleagridis from pheasants and chickens. The wide distribution of H. meleagridis is attested by reports of enterohepatitis from the Dutch East Indies (Picard 1^29); Japan (Niimi 1930); Germany (Enigk and Wetzel 1938); Italy (Menzani 1939); Brazil (Santos 1944); Poland (Kuprowski 1950). The etloDogical agent producing histomoniasis in turkeys is the protozoan parasite, H. meleagridis, described by Smith (1695) as Amoeba meleagridis♦ However, several other protozoan parasites have been reported as the causative agent of enterohepatitis. Cole et a l . (I9l0) reported that a coccidium and not A# meleagridis was responsible for blackhead in turkeys. Coccidiosis occurs in turkeys and may be confused with histomoniasis. Distinctions between coccidiosis and black­ head were described by Schofield in 1926. Trichomoniasis has also been confused with histomoni­ asis. Hadley (1916a, 1916b, 1917) described the tricho­ monas organism, its method of entrance, and the development of the disease in so-called blackhead infections in turkeysMacroscopic differences between lesions caused by Histo- monas and Trichomonas were observed by Allen (1914) and Santos (1944). However, Allen (1941) reported a Penta- trichomonas associated with enterohepatit is. Menzani (1939' concluded that the primary cause of blackhead was a BXastomyoea. 4 Turkeys acquiring histomoniasis under natural con­ ditions may also be infected with coccidia and trichoMonas• Santos (1944) stated that Enigk and\»fetzai (1938) was able to culture Mycotorula albicans from turkeys with enterohepatitis. The cultured M. albicans injected into turkeys pro­ duced enterohepatitis# H. meleagridia exists in various forms. Tyzzer (1919, 1920a) described three phases; invasive, vegetative and re­ sistant stages. The invasive form, found in early lesions, appears amoeboid in structure. The cytoplasm stains basophilic, and ingested particles may be present. The vegetative phase characterizes older lesions and shows: loss of motility; increased size; and clear, trans­ parent, basophilic cytoplasm. The vegetative phase lacks cytoplasmic inclusions. The oldest lesions present the resistant stage. The cytoplasm stains acidophilic and coarse granules fill it. Due to the tissue reaction of the host, this stags is ofton orclosed in definite spaces, or ingested by phagocytAC cells. The organism© often appear in masses or "nests". A flagellated phase has been observed by Tyzzer et a l . (1921) in the lumen of the cecum. have been reported. present• One to four flagella No axostyle or undulating membrane is Infection with H, meleagrldis occurs by ingestion of soil containing the histomonads or embryonated H. gallinae ova, and the inoculation of infected organs via various routes. The protozoan is discharged with the feces of infected birds. According to Tyzzer (1920b), Tyzzer and Collier (1925) and Tyzzer and Fabyan (1922), healthy turkeys de­ veloped enterohepatit is when fecal material from infected birds was Immediately ingested. According to Graybill and Smith (1920) ingestion of the embryonated ova of Heterakis papillosa (= H. gallinae} produced enterohepatitis in turkeys. (1922) Tyzzer and Fabyan observed that embryonated ova of H. papillosa were important in the natural transmission of histomoniasis. McKay and Morehouse (1947) reported the inoculation of em­ bryonated H. gallinae ova to be a convenient and successful laboratory procedure for producing histomoniasis. Swales (1948) observed that washed embryonated H. gallinae ova given per os, intra-cecal inoculation of washed infective larvae, and intra-cecal inoculation of larvae sterilized in hydrogen peroxide produced enterohepatitis• Ground-up cecal worm eggs (fresh and embryonated) failed to cause enterohepat!tis. Therefore, Swales suggested that living h* gallinae larvae were needed to produce the disease. The histomonas organism in was reported by Tyzzer (I92b) the tissues of the larvae of Heterakis vesicularis (= H. gallinae). Connell (1950) observed that only H. gallinae larvae with cuticular swellings produced enterohepatit is • Tyzzer and Fabyan (1920, 1922) produced enterohepatit is in turkeys by subcutaneous and oral ted liver. Intravenous inoculation of Inoculations of liver lesions seldom caused enterohepatitis (Tyzzer et a l . 1921). Tyzzer and Collier (1925), Delaplane (l v 3 2 ), and Farmer and Stephenson (1949) and Lund (195 5) produced enterohepatit is in turkeys by rectally injecting suspensions of infected liver. .Report 3 by Harrison et a l . (1954) indicated that Seitz filtrates prepared from infected liver produced no sickness or lesions when injected into the livers of ex­ perimental turkey poults by laparotomy. The possibility of flies and grasshoppers serving as mechanical carriers of H. meleagridis was reported by Tyzzer (1920b) and Frank (1953). Many details of the life cycle of H. meleagridis are still unsolved. Natural infection occurs by ingestion of the parasitic protozoa in the droppings of infected birds, or from soil contaminated with embryonated H. gallinae ova containing H. mealeagridis. The protozoa first localize in the ceca and later invade the liver. The organism may be demonstrated in the droppings of infected birds in from one to seven days following infection. Smith (l^lb) stated that multiplication of the protozoa was intercellular, and that histomonads were transported to the liver by phago­ cytic cells, Tyzzer (1919) reported that multiplication occurred by binary fission, and that the protozoa exhibited amoeboid movement by which they migrated through the tissues Histomonads were observed in hepatic blood vessels by Gray­ bill (1925) and Farmer et a l . (1951), These investigators concluded that the infection spreads from ceca to liver via the portal circulation. According to Graybili and Smith (1920) and Graybill (1925), the H, gallinae larva may be a favorable factor for the development of the histomonas or­ ganism. Tyzzer and ColJ1er (1925) found that passage of the protozoa tiirough the ceca was necessary I'or the develop­ ment of the disease. According to Delaplane and Stuart (1935), clamps occluding the ceca protected turkeys against enterohepat itis. The s}Ttptoms occurring in turkeys infected with entero­ hepat it is are not specific for H, meleagridis. Observations of symptoms, age susceptibility, incubation period and mortality have been reported by: Smith (1895), Curtice (1907a, 1907b), Pernot (190V ), Tyzzer and Fabyan (1920), Graybill (1925), Doyle (1929), Santos (1944), Swales and Frank (1948) and Kuprowski (1950). The term "blackhead" used in describing this disease is a misnomer. The head may turn a blue-black, but this symptom is not characteristic of a histomonas infection. their appearance are: drooping Symptoms observed, in order of drowsiness, sulfur colored droppings, wings and tail, and anorexia. In severe cases death may occur before any symptoms appear. Mortality may be 100 per cent in severe outbreaks. The mortality rate depends, among other conditions, upon the age of the turkey. Birds,one to four weeks old, have been observed to be the most susceptible, however, older turkeys may become infected but the mortality rate is lower. The incubation period is from 11-17 days, with death occur­ ring between the 12th and 21st day after infection. Characteristic lesions due to H. meleagridis are pro­ duced in the ceca and liver. One or both ceca may be in­ volved, and liver lesions occur in practically all cases. Raised, thickened, yellowish ulcerations and occasional hemorrhagic areas appear on the serosa of the ceca. The ceca are enlarged and the lumQiinafilled with a tough yel­ lowish core. The surface of the liver is covered with small, round, yellow-green depressed lesions, and the liver is enlarged. These characteristic lesions have been re­ ported by Curtice (lyOVaj, Pernot (I9 O/), Smith (1915), Tyzzer (1920b), Graybill (1925), Rettger and Kirkpatrick (19 27), Doyle (1929), Picard jpicKay and Morehouse (1947). (1929), Santos (1944), and Shope (194b), described "caseous" necrotic areas ii the liver and ceca. Parmer et a l . (1951) observed hyperemia, edema, and polymorpho- nuclear infiltrat ion of tiie mucosa and submucosa of the ceca in the early stage of enterohepatitis. In later stages, the inflammatory reaction and protozoal infiltration extended into the muscular layers* tozoa* The ceca exhibited "nests" of pro­ Dense areas of "round cell" inflitrati on, cloudy swelling, degeneration and necrosis of the cells character­ ised the liver lesions. Giant cells contained protozoa. Farmer described the lesions in the liver as, "a karyolytic necrosis accompanied by a subacute type of inflammatory re­ sponse". Chester and Robin (lyouj observed o r g a n i s m s within liver cells, but were not certain if these were the nistomonas organisms. Desowitz (1950) noted protozoan or­ ganisms in epithelial cells of the gut in turkeys dying from blackhead. Most authors are now in agreement with Tyzzer (1919) and Smith (1915), that the histomonas agent observed in lesions of the ceca and liver is intercellular. Blackhead lesions have been reported in organs other chan the ceca and liver. Chester and Robin (19G0) observed pale, mottled areas in the kidney and necrosis of the spleen. Secondary lesions of the lungs and rarely of the kidneys A were noted by Tyzzer and Fabyan (l92u). Devolt and Davis (1936) produced sinus lesions by inserting liver infected with histomonas beneath the skin. Microscopic examination of white round spots on a kidney showed an infiltration of mononuclear cells, areas of necrosis, and the histomonad 10 agent, which, appeared identical with those observed in the liver (Levine 1 9 4 t )* Kuprowski (1950) reported congestion of the parabronchi of the lungs, and enlargement and con­ gestion of the spleen and kidneys. A small focus of pro­ tozoa was noted by Farmer et a l . (1951) In the spleen of turkeys which died on the 12th day after infection but no tissue reaction was ouserved. McGuire (1955) Pathology was noted by in lungs, kidneys, heart and proveniriculus of turkeys with blood-induced blackhead infection. McGuire transfused cecal vein blood of a diseased bird into the wing vein of susceptible turkeys. While reviewing the literature concerned with lesions produced by H. meleagridis, few observations were found on the normal histolo©r of the turkey. Detailed microscopy of the duodenum of the turkey was reported by Rosenberg (1941); the histology of the pancreas was studied by Lucas (1951); and Demke (1954) described the microscopic anatomy of the duodenum, small intestine, cecum and rectum of turkey poults. Calhoun (1954) studied the normal histology of the digestive tract of chickens of various age groups. Histo­ logical descriptions of the digestive, respiratory, uri­ nary and reproductive organs of the chicken were included by Grahame and Bradley (1950). These two references were used as a basis for comparing the histology of the chicken with that of the turkey. 11 Numerous observations concerned with the hematology of chickens have been published, but few studies have been re­ ported on the blcod picture of turkeys. and Rhian et a l . (1944) reported on Scott et a l . (1933) hemoglobin content and blood chemistry determinations of turkeys. Tables pre­ sented by Virth (1950) and Vintrobe (1952) show values for the erythrocyte, leukocyte and differential counts, and hemoglobin content for normal adult turkeys. Descriptions of the circulating and bone marrow blood cells have re­ cently been published by Lucas and Jamrez (1956). Alterations in the differential count of turkeys ex­ posed to H. meleagridis were reported by Johnson and Lang (1939). McGuire and Cavett (1952) observed changes in the total red and white counts along with alterations in the blood chemistry of turkeys suffering from enterohepatitis. 12 MATERIALS AND METHODS The turkeys used in this study were Beltsville Whites obtained from the Zeeland Hatchery, Zeeland, Michigan. total of twenty turkeys was A employed and all birds were ob­ tained from the hatchery as one day old poults. Eight poults were obtained from the hatchery on Novem­ ber 5, 1954 and twelve on February 24, 19 55. were placed in The turkeys separate units (16 x lb x 15 inches], with individual feed and water troughs, in a chicken battery. The turkeys were cleaned, watered and fed (turkey starter feed) daily. Turkeys designated as controls were placed in the battery units above those which were to be inoculated, thereby lessening the chance of the control turkeys becom­ ing contaminated with the feces of the inoculated birds. Fecal contaminâtion of all individual poults was kept at a minimum by a wire screen separating the dropping pan protected the turkey poults in which the turkeys from the units below from the fecal material from the turkeys in the units above. Heterakis gallinae ova may become infected with the etiological agent which produces blackhead. Therefore, em­ bryonated ova of H. gallinae were employed in this experi­ ment to produce enterohepatitis in turkeys. was obtained from ceca H. gallinae of chickens killed at a commercial 13 poultry plant in Lansing, Michigan. The c eca were slit open, scraped and washed with water into a number 1 mesh sieve. These scrapings were washed again and the remaining contents transferred into a glass howl from which the para­ sites were removed. The female H. galllnae were separated from the males with the aid of a dissecting microscope and placed in normal saline. A tissue homogenizer was employed to macerate the parasites and thus release the ova. This suspension was centrifuged, the eupernate decanted and u.5 per cent formalin added to the remaining ova. The formalin suspension was transferred to Petri dishes and incubated at room temperature. After four weeks of incubation, the for­ malin suspension was centrifuged, and the sediment contain­ ing the embryonated ova was washed three times with normal saline, suspended in normal saline and stored in the re­ frigerator. The embryonated ova were counted by the following method: five 0.05 ml samples of the ova suspension were placed on glass slides and the embryonated ova counted. The number counted was multiplied by 20 in order to obtain the number of embryonated ova per ml. Counts ranged from 300 to 600 embryonated ova per ml. A total of twelve turkey poults» 45 days old, were inoculated orally with embryonated H. gallinae ova (l ml con­ taining 300 to 6UU ova) py means of a glass pipette. were used as controls. iSight birds 14 The weights, rectal temperatures and blood samples were taken from allturkeys on the first day after inoculation and every third day thereafter until the 14th day; from the 14th day until death they were taken every second day. Blood samples were obtained by wing vein puncture using a sterile 22 gauge needle. Sach succeeding sample was taken from alternate wing veins in order to minimize trauma. Ap­ proximately 0.5 ml of blood was aspirated into a 2 ml sy­ ringe, immediately placed into a dried oxalate tube, (Wintrobe 1952) and shaken for one minute. A drop of oxa- lated blood was placed on a elide, smeared and stained with Vright *8 stain in the usual manner. The blood was drawn into a r.b.c. diluting pipette, diluted 1:200 and allowed to stand for one hour. A solution of phloxine dye as sug­ gested by Wiseman (1931) was used as the diluent. iSrythro- cytes were counted in the hemocytometer in the usual manner. Leukocytes were counted by the indirect method of Olson (1^37 ) and the total leukocyte count calculated by the fol­ lowing formula: t otal leukocyte = 10 count 9 number of acidophilic X 200 X 100 % acidophil1c cells counted in hemocytometer( cells counted in blooa smear A Haden-Hauser hemoglobinometer was used to measure hemo­ globin content. All infected and control turkeys were autopsied as soon as possible after death. Carcasses of birds not 15 immediately autopsied were placed under refrigeration until the necropsy could be performed. rificed by exsanguination. Specimens were removed from the carcass in the following order; and duodenum, The controls were sac­ small intestine, junction between gizzard ceca, re c t u m , bursa cloacae, kidney» liver, spleen, pancreas, gizzard, junction between gizzard and proveniricuius, proveniricuius, junction between provenir icuius and esophagus, esophagus, junction be­ tween esophagus and crop, heart and lungs. Anterior, middle and posterior sections were taken from the esophagus, intestine and lesions. ceca. small All specimens were observed for gross Lengths and diameters of the ceca were measured, and the hearts, livers and spleens weighed. Specimens of the above mentioned organs were fixed in Bouins solution and stored in 70 per cent alcohol. They were dehydrated and infiltrated according to the butyl al­ cohol -paraffin mush method of Johnston et a l . (1943). The specimens were embedded in Tissuemat* and sectioned at 6 microns. The following staining methods were used; Harris he­ matoxylin and eosin stain as modified by Malewitz and Smith (1955); Welgert*s elastic tissue stain; Van Gieson's picroacid-fuchsin for white fibrous connective tissue; M a y e r ’s mucicarmine method for mucin, Hoepke (1930), and the periodic * Fisher Scientific Co. 16 acid-Schiff reaction, MàcManus (1948), was used on sections of liver, lung, kidney, spleen and ceca. Sections were made by the above methods from the organs of two control and four infected turkeys# one inoculated turkey which never exhibited symptoms of an infection, and one turkey which showed signs of recovery. 17 R8SÜLTS AHL DISCUSSION Gross Anatomy The gross structures of the digestive tract, includ­ ing appendages, of the turkey are essentially the same as the ne of the chicken as described by Grahame and Bradley (1950) and Calhoun (1954), Plate I shows the relationships of the gross structures of the digestive tract of the tur­ key. The beak and structures of the oral cavity are illus­ trated in Plate II, and are similar to those of the chicken as observed by Grahame and Bradley (1950) and Calhoun (1954). Longitudinal rugae characterize the mucosal surface of the esophagus. Numerous esophageal gland openings can be observed as small elevations on the mucosal surface; they decrease in number near the proventriculus. A definite line of demarcation separates the mucosa of the esophagus from that of the proventriculus. Six groups of longitudi­ nally arranged gland-like openings are present where the esophagus enters the proventriculus. These groups consist of two parallel rows, each of which is made up of from three to five openings (Plate III). Papillae with gland openings appear on the mucosal surface of the proventriculus. Plicae are concentrically arranged around the lô papillae and are irregularly disposed between them (Plate IV). The characteristic papillae and plicae end abruptly at the junction between the proventriculus and gizzard (Plate V), and the horny layer of the gizzard can be ob­ served. The musculature of the gizzard is characterized by two thin musculi intermedii: one arising near the proventricu­ lus, and the other at the posterior end of the gizzard. The two musculi intermedii are between the thick musculi latérales. The muscles insert on a tendinous aponeurosis on the lateral side of the gizzard. At the junction between gizzard and duodenum, the mu­ cosal surface changes from the thick horny layer of the gizzard to an area with irregularly arranged plicae (Plate VI). Villi are characteristic of the mucosal surface of the duodenum (Plate VII), the remaining small intestine, cecum and rectum. Folds with numerous lymph follicles constitute the bursa cloacae (Plate VIIl). 19 Plate I. Digestive tract of turkey p o u l t . A. B. CD. P. G. H. I* J. Beak Tongue Mouth Pharynx Bsophagus Crop Proventriculus Musculari latérales Muscular 1 intermedii Tendinous aponeurosis of the gizzard K* L% M. N. O* P. R* S. T* Duodenum Pancreas Gall Bladder Liver Jejunum and ilium Ceca Rectum Cloaca Bursa cloacae Anus FLATS I 20 19 Plate ^ Digestive tract of turkey poult A B. Ce D. Be P. Qe He le Je Beak Tongue Mouth Pharynx Seophegue Crop M Proveniriculue Muscular1 lateralee Muscular 1 iokermedil Tendinous mponeuros of the glzsard K. O Le Me S. Oe Duodenum Pancreas Gall Bladder Liver Jejunum ai ilium Pe G#ca q. Rectum' Cloaca Bursa cloacae Anus Re Se Te # % j), PLATS I 20 & 21 Plate II. Mouth parta of the turkey. A. B. C. D. 3. P. 1* H. 6% hesal opening Opening for medial palatine glands Papillae separating mouth from pharynx Pharynx Tongue Lingual papillae Aditus laryngis Laryngeal papillae PLATB II 22 21 8 Plate II. Mouth parte of the turkey. A. B. C. D. E* P. G. H. W 6r Keeal opening , , Opening for medial palatine glands Papillae separating mouth from pharynx Pharynx Tongue Lingual papillae Aditus laryngis Laryngeal papillae PLATE II ( 22 23 j u n c t i o n between e s o p hagu s and proventi’icu­ lus ( B ) . Hote c r y p t - i i k - ope ni ngs (C) near j unction. lUx PLATE III -h 24 J) T±sze IÏI- Junction between e sephAc.u s (A) and proventr icu­ lus (B). Note crypt-! openings tC ) near jun ction. lux PLATE III 24 25 nate IV. Proventriculus showing papillae with gland opening ^A ;* concentrically a^rranged plicae (B)^ inter papillary plicae (C). 12.5x PLATE IV 26 Plate IV, Proventriculus showing papillae with gland opening A /, concentncally arranged plicae (B), inter papillary plicae (ü). 12.5% D a PLATE IV 26 27 Plate V. Junction between proventriculus (A) and gizzard (B). 14x PLATE V 2d IP- m K Plate V. Junction between proventrIculus (A) and gizzard (B). 14x PLATE V 28 29 Plate VI. Junction between gizzard (A) snd duodenum (B). Note area with irregularly arranged plicae (C) 8x PLAIE VI 30 ■plate VI. Junction between gizzard (A) and duodenum (B). Mote area with irregularly arranged plicae (C) 8x A 30 PLAIE VI 3 T 31 Plate Vil. Villi in duodenUTn. 11.x PLAIE VII 32 ol Plato Vil. Villi in duodenum* 11.x PLATE VII 32 à 33 Plate VIII. Poids of bursa cloaca (B ). 4.5x , lymph follicles PLAIE VIII 34 a Plat e VIII. Poids of bo rsa cloaca pA), lymph follicles (3 ) . 4 . r; X PLATE VIII 54 35 Kormal Histology of Turkeys Esophagus (Plate IXJ A typical mucous membrane including a thick stratified squamous epithelium was present* The outer epithelial layer had a tendency to desquamate, and the basal layer projected down between the papillae of the tunica propria. Large, multi-lobed mucous glands, were present in the tunica propria. njaal Tall columnar epithelium which decreased to cub- epithelium as it approached the surface lined the mucous glands. The tunica propria was composed of fibrous connective tissue and contained many blood vessels* Elastic and lymphoid tissue were not prominent in the tunica propria of turkey poults. The muscularis mucosae was composed of thick involuntary muscle arranged longitudinally, and was about half as thick as the longitudinally arranged muscularis externa. The muscularis mucosa followed the folds of the mucous membrane. The suomucosa was thin but distinct, and cumposed of fibrous connective tissue with oiood vessels and occasiunax nerves. The muscular is externa was composed oi a thicJf inner circular layer and a thin outer longitudinal layer of in­ voluntary muscle. A small amount of connective tissue 36 Pxat^ IX. Esophagus showing stratified squamous epithelium (.A), tunica propria (B), mult i-xobed mucous glands (C), muscularis mucosa (L), submucosa (E ], and circular layer of muscular is externa (FJ. 200x PLATE IX 37 % m m %f* ' '..^ ^v-V-;.ÿ 'f . '. # ' .''A *. '*• 36 a liate IX. Esophagus showing stratified SLiiamous epithelium (A)t tunica propria (B), multi-iobed raucous glands (C), muscularis mucosa (Lj, submucosa (E), and circular layer of muscular is externa (F). 200 x PLAIE X3C 37 0^ m m '•*f * » « '» 38 containing blood, vessexs and nervous elements was present between the two layers of the muscuxaris externa. The adventitia was thin and consisted of white fibrous connective tissue, nerve bundles, littxe elastic tissue and blood vessels. The age of these turkey poults may explain the lack of xymphoia tissue aixQ elastic fibers. Calhoun (1954) ob­ served that elastic tissue in the submucosa became more dense in older chickens. Crop The stratified squarjous epithelium of the crop ap­ peared slightly thicker than that of the esophagus. Glands were present in the tunica propria of the crop near the Junction with the esophagus, and were absent in the di­ verticulum of the crop. The papillae of the tunica propria projecting into the epithelium were more rounded. The muscularis mucosa consisted of smooth muscle arranged longitudinally. A suomucosa was present. The muscularis externa w^as composed of inner circular and outer longi­ tudinal smooth muscle layers. Junction Between Esophagus and Proveniriculus The stratified squamous epithelium of the esophagus narrowed as it approached the proveniriculus. At the Junction the epithelium changed to the simple columnar of 39 Plate X* Junction between esophagus and proveniriculus. Note sti’atified squamous eplthexium of esopha­ gus (A) and the abrupt change to simple colum­ nar epithelium of provenirIculus (B)* Tunica propria (C), muscularis mucosa (B), and deep proveniricular glands (E). 23ux PLAIS X m i. Jtf .t m 40 - m 7 - '" «' ’ MÊÿB mmmÉf t • ?î5î*riZV. u V"* W; 39 Plate X. Junction between esophagus and proveniriculus. Note stratified squarrjous epithoxiuin of esopha­ gus (A) and the abrupt change to simple colum­ nar epithelium of proveniriculus (3). Tunica propria (C), muscularis mucosa (B), and deep provenirIculsr glands ). 23ux a PLAIS X 'M. » 40 41 the proveniriculus (Plate x ) • The papilxae of the esopha­ geal tunica propria shortened near the Junction and the mucous glands in the tunica propria ended abruptly where the epithelium changed. The proventricular glands extended into the esophageal region of the junction. The muscularis mucosae of the esophagus was continuous with that portion of the proventricular muscularis mucosa beneath the deep glands. Tonsil-like aggregated lymph nodules which opened onto the stratified, squamous epithelium of the esophagus were observed between the esophagus and proventriculus. The stratified squamous epithelium involuted forming a crypt and covered the surface of the lymph nodules* Serial sections revealed the duct of an esophageal gland opening into the side of the crypt of these aggregated lymph nodules. The columnar epithelium lining the duct of the esophageal gland changed to cuboidal epithelium where it opened into the crypt (Plate X I J . Descriptions of this type of aggregated lymph noduxes in fowl were not found in the literature. Pro ventriculus The histology of the proventriculus of the turkey is similar to that of otner birds as aescribed by Elias U 9 4 5 ) , Grahaiae and Bradley (19601 and Calhoun (1954). The plicae and sulci of the proventriculus were lined Dy simple columnar epithelium. These epithelial 42 Plate XI* Section of crypt anown xu Plate III. Duct of esophageal gland (A) opening into a crypt (B) near a lymph nodule (C). 20ÜX PLATS XI 42 % n a 42 (f Plate XI# Section or ahown in Plate III. Duct of esophageal gland (A) opening into a crypt (B) near a lymph nodule (C). 200x FLAIB XI IS» I m $ 43 44 cells stained with a mucin stain. xhe tunica propria which extended up into the plicae consisted of dense white fi­ brous connective tissue, numerous blood vessels, and a rich supply of elastic fibers* observed in the mucosa. Lymphoid tissue was not The deep proventricular glands were separated from one another by connective tissue from the tunica propria, tissue and by muscle fibers from the muscularis mucosa (Piate XII). The proventricular gland tubules were composed of cuboi ial-1ike cells with a central nucj.ews. T hey upened into a central collecting cavity lined by columnar epithelium* a positive stain for mucin. These columnar cells took The muscularis mucosa was tnick, arranged longitudinally and situated both above and beneath the glands* The submucosa was thin and appeared absent in places. White fibrous connective tissue, elastic fibers and blood vessels were observed in the submucosa* The muscularis externa consisted of two layers of involuntary muscle: a thick inner circular, and a thin outer longitudinal layer. A prominent adventitia of con­ nective tissue, elastic fibers, nerves and numerous blocd vessels covered the entire organ. (Plate XIII)- Junction Between Proveniriculus and Gizzard The plicae of the proventriculus ended abruptly, and a keratinized layer was observed above the sulci as they 45 Plate XII. Proventriculus . Mucous membrane lined by simple columnar epithelium (A), tunica propria (B), muscularis mucosa (C), deep prcventricular gland (Ij ), and central collecting cavity of gland lined with columnar epithelium (B). loux PLAXS XII 46 a Ê mm I d II i 40 Plate XII. Proventriculus. Mucous membrane lined by simple cQ-urnnar epithelium (A), tunic^ propria (B), muscularis mucosa (C), deep prcventricular gland (D), and central collecting cavity of gland lined with columnar epithelium (li). loux PLATS XII 46 mm. 9 m ü m % 47 Plate XIII. Elastic fibers (A) In muscularis externa of prcventr iculus. (‘W eigert’s) 42Ux PLATE XIII 48 47 A plate XIII. Elastic fibers (a ) In muscularis externa of prcventriculus. (weigert’s) 420x PLATE XIII 48 */ / -i-A w m \ A 49 approached the gizzard* Lymph nodules were present in the tunica propria of the proveniriculus near this junction. The tunica propria and suhmucosa of the proveniriculus joined and continued into the gizzard as the suhmucosa. The deep proveniricular glands ended abruptly at the junction. The portion of the muscularis mucosa above the deep siwas not observed at the junction. glands of the proventriculusjwas That part of the muscular is mucosa below the glands y and the inner circular layer of the muscularis externa continued into the gizzard to eventually fuse with the mu seuli Intermedii. The outer longitudinal layer of the pr oventricu­ lar muscularis externa appeared to join the musculi latér­ ales of 'the gizzard near the junction. Gizzard (Plate XIV) The turkey gizzard corresponded to that of the chicken as described by Grahame and Bradley (lybO) and Calhoun (1954). The epithelium of the mucous membrane was simple columnar covered by a keratinized layer. A horny layer with columns and striations as described by Calhoun (19 54) was observed. The tunica propria consisted of collagenous connective tissue, elastic fibers and glands lined by cuboidal epithelium, and was filled presumably with a keratohyalin substance which stained bright red with B&E stain. A muscularis mucosae was absent. 50 Plate XIV. Gizzard. Mucous membrane (A), tunica propria (B), glands (C), submucosa (D), parallel bands of involuntary muscle (E), bands of dense white fibrous connective tissue (P). lyQx 51 PLATE XIV S I 3 - V'f- • 50 Plate XIV. Gizzard. Mucous membrane (A), tunica propria (Bj, glands (C), submucosa (D), parallel bands of involuntary muscle (E), bands of dense white fibrous connective tissue (P). lyOx a D a PLAIE XIV 51 I I 52 The thick suhmucosa was composed, of dense areolar connective tissue with relatively few elastic fibersBlood vessels and nerves were present between the submucosa and tunics propria, within the submucosa, and between the submucosa and muscle layer. The heavy muscle layer was composed of thick parallel bands of involuntary muscle. Bands of dense white fibrous connective tissue running opposite to the muscle separated these parallel muscle bands. Calhoun (1954) observed white fibrous cartilage at the junction of the smooth muscle and fibrous aponeurosis. Developing cartilaginous tissue appeared in this area in these turkey poults. A thin layer of areolar tissue surrounded the gizzard. Blood vessels and nerves were observed in this fibrous layer. Peritoneum covered the entire organ. Junction Between Gizzard and Duodenum The horny layer and glands characteristic of the giz­ zard ended, and tubular mucous glands replaced them before the villi and crypts of Lieberkuhn of the duodenum began, lymph nodules were present in the tunica propria at the junction. The muscularis mucosae of the duodenum extended for a short distance into the gizzard. The submucosa and the two layers of the muscularis externa were indistinct at the junction, becoming better defined further down the duodenum. Calhoun (1954) reported the presence of grands 53 similar to Brunner's glands in the anterior portion of the duodenum, but ïione were observed in the turkey* Rosenberg (1941) and Demke (19 54) also repoited the absence of Brun­ ner's glands in the duodenum of the turkey. Small Intestine (Prate XV) Distinctions between the duodenum, jejunum and ileum cannot be observed in the avian small intestine (Grahame and Bradley, 1950; Calhoun, 1954; Demke, 1^54). Simple columnar epithelium with a cuticular border lined the mucous membrane. stain were present. Goblet cexis which took a mucin Villi, which branched several times, were observed throughout the small intestine. Crypts of Lieberkuhn opened between the vitli. Branched The tunica propria extended up into the villi and contained diffuse lymphoid tissue, few lymph nodules, fibroblasts, an oc­ casional argentaffin cell, connective tissue, muscle and a few eisstic fibers. The muscularis mucosre was distinct and consisted of one layer of longitudinal muscte. Muscle fibers from the muscularis mucosae extended into the tunica propria. The thin submucosa was indistinct and composed of areolar connective tissue. The muscuxaris exoerna exhibited a thick inner circu­ lar and a thin outer longitudinal layer of muscle. A thin Layer of connective tissue containing blood vessels and 54 Plate XV. Small intestine. Villi (A), columnar epithelium (Bj, crypt of Lieberkuhn (C), tunica propria (L), muscularis mucosa (E ), submucosa (F), circular (G) and longitudinal (K) muscle layers of mus­ cularis externa, and the serosa (I ). 200x PLAIE XV 55 H G m 54 % G Plate XV. Small Intestine. Villi (A), columnar epithelium (Bj, crypt of Lieberkulm (C), tunica propria (D), muscularis mucosa (E), submucosa (F), circular (G) and longitudinal (K) muscle layers of mus­ cularis externa, and the serosa (l). 20Ox PLATE XV 55 i! m 56 nerves surrounded the muscularis externa. A serosa covered the entire organ. The microscopic anatomy of the small intestine was similar throughout. The villi decreased in height, and branching was less prominent in the lower two-thirds of the small intestine. The outer longitudinal layer of the muscularis mucosae appeared thicker toward the- rectum. Cecum (Plate XVIJ The microscopic anatomy of the ceca was similar to that of the small intestine. The mucous membrane was lined by simple columnar epithelium with a cuticular border. The epithelial cells took a mucin stain, and goblet cells were numerous. between the villi. Crypts of Lieberküîin opened Demke (1954) reported that villi were absent in the ceca of the turkey. the ceca in this *investigation. Villi were observed in In the proximal portion, the villi were similar to those of the small In%,estine: they became shorter in the mid-portion, and appeared leaflike at the distal end. The tunica propria contained lymph noduies and diffuse lymphoid tissue. The muscularis mucosa consisted of one layer of circular muscle which followed the folds of the mucous membrane. The suhmucosa was distinct and consisted of fibro­ blasts, few elastic fibers, and blood vessels. 57 Plate XVI. Cecum showing villi (A), columnar epithelium (E), crypts of Lieberkuhn (Ç), tunica propria (D), muscularis mucosa (E), submucosa (F), circular (Gj and longitudinal (H) muscle lay­ ers of muscularis externa, and the serosa (X). 360x PLATE XVI m, 58 57 X Plate Cecum sho«\Lng vil^i ^a ) , columnar epithelium (B)» crypts of irfberkuhn (C), tunica propria (B), museularia mucosa (E), suhmucosa (J)» circuler (G] and longitudinal (H) muscle lay­ ers of muscularis externa, and the serosa (I). 260x € A a PLATE XVI 58 . ' 4" % *1 ém\. ■ifiîS''vi<«-4‘)S^' s.-iBr~ r 59 The muscularis externa was characterized by inner cir­ cular and outer longitudinal muscle layers. A serosa, rich In nerve elements^ surrounded the muscular!s externa* Rectum The histology of the rectum appeared similar to that of the small intestine. The mucous membrane was lined with simple columnar epithelium with a cutlcular border, and goblet cells were numerous. Villi were present, lymph nodules and diffuse lymphoid tissue were abundant. Bursa Cloacae (Plate XVII) The mucosa was characterized by longitudinal folds consisting of numerous lymph follicles* The follicles had a dense cortex and a medulla similar to that of a germi­ nal center in a lymph node* The medullary portion was in contact with the epithelial lining in places along the longitudinal folds. The cortex was distinctly separated from the medulla by a row of compact cells* The medulla, in many lobules, seemed to be free from lymphocytes and presented only the reticular framework. Numerous capil­ laries were present in the medulla, but not visible in the cor tex * The epithelium covering the tips of the folds was pseudostratified columnar, and between the folds was simple columnar. The epithelial cells did not take a mucin stain. A muscularis mucosa was absent. 60 Plate XVII- Bursa cloacae showing a trabecula '(A), septa (B), a follicle with a cortex. (C) and medulla (B), pseudostrait if ied columnar epithelium covering the folds J. Eote the medullary portion in contact with the epithelium at F. 300x PLATE XVII 61 ss^ % K 60 Û Plate XVII. A Bursa cloacae showing a trâlDecula ‘(A) , septa (B), a fell:cl- with a cortex (C) and medulla (B), pseudostratifled columnar epithelium covering the folds (K). Mote the medullary portion in contact with the epithel2um at F. 50Ox % PLATE XVII 61 S % 62 The subTnucosa was thin but distinct and consisted of white fibrous connective tissue and numerous elastic fibers The submucosa extended up into the folds of the mucosa in the form of trabeculae. The trabeculae extended up the center of each fold and septa branched off to surround each follicle. The trabeculae weie rich in blood vessels. The muscularis externa consisted of an outer circular and inner longitudinal layer of involuntary muscle. A thin serosa surrounded the entire organ. Liver The liver of the turkey was similar to that of the chicken as described by Calhoun (ly54). The liver of do­ mestic fowl is less lobulated than that of other domesti­ cated animals and interlobular septa 3 ess distinct. Central veins were lined with thin endothelium, and prominent sinusoids entered them (Plate XVIII). Endotheli­ al cells also lined the sinusoids, and Kupffer cells were distinct. The portal canal contained the portal vein, hepatic artery, bile ducts and lymphatics. The liver parenchyma had a tubular arrangement in cross section, and appeared plate-like in longitudinal section. Dense areolar tissue was observed aruuria blood vessels, and in the thin capsule of Giisson surrounding the liver. 63 Plate X\'^III. Liver. iB). Sinusoid (A) entering central vein 5yOx PLAIE XVIII g4 :V ' H \ % 63 Plate XT/III. Liver. Sinusoid (A) enter:rg central vein iB). 5yOx PLATE XVIII 64 % A’ k V t % %. A • * $ <* À ^ vw « .> %* • »■ • V ' t Aï 65 Pancreas (Plate XIX) Mo differences were observed between the pancreas of the turkey and that of the chicken as described by Grahame and Bradley (1950) and Calhoun (1954). A thin capsule composed of collagenous and elastic fibers surrounded the pancreas. A serosa covered the cap­ sule. The secretory cells of the pancreas were pyramidal in shape, with a spherical nucleus near the base of the cell, and had a granular cytoplasm. Gentroacinar cells, and alpha and beta islets were observed. The collecting ducts were lined with cuboidal epithelium, and were not numerous. Spleen (Plate XX) The Spleen of the turkey was similar to that of the chicken as described by Grahame and Bradley (l95o). A thin capsule of connective tissue, smooth muscle and occasional elastic fibers surrounded the spleen. Trabeculae were not observed. The capsule was covered by a thin serosa. The parenchyma of the spleen consisted of a reticular network with numerous small circumscribed white pulp areas surrounded by areas of red pulp. Several (2-4) central arteries were observed within the white pulp. pulp consisted chiefly of lymphocytes. The white The surrounding 66 Plate XIX. Pancreas with alpha (a ) s,nd oeta (b ) islets bOüx PLATE XIX 67 t « % sff % 5? r g y;® i r. if y 66 a Plate XIX. Pancreas with alpha (A) and oeta (B) islets bUUx PLATE XIX f I k 67 9 w JS â A kf 4 2 ? » y à 68 Plate XX- SpleenCentral artery (a) surrounded by white pulp (B) and red pulp ( c) * ' 83ux PLATS XX 6V 11 r rt/white cells H e t . Lym. M o n . Eos . -Bas 43.4 50.6 1.9 0 .9 3.2 Wirth (1950) —— 2,700 34,100 34.5 63.6 1.0 2.5 2.5 McGuire & Cavett (1952) 8-18 wka • 2,476 38,700 9.3 43.2 43.6 4.9 0.1 4 .6 Wintrobe (1952) —— —— 11.2 1 Present In­ vest igation 5-8 wks. 2,270 gms I 1.930 ' 1 50,685 1 — —— ” 10.2 1 29.9 61.4 1.5 1.5 , Ü .1 90 Symptoms Due to Hiatomcnae Meleagridia Investigators have used various methods for infecting turkeys with H. meleagridle■ - In this investigation, typi­ cal enterohepatit is was produced in turkeys by the oral method of inoculation as suggested by McKay and Morehouse (1947). The advantages of this method are: it closely resembles the natural mode of infection, typical lesions are produced, and it is a convenient laboratory procedure. Four out of eight Bextsville white turkeys were inoculated per OS with 300-600 embryonated H. gallinae ova on Decem­ ber 20, 1954* trols. The remaining four turkeys served as con­ The experiment was repeated on April 11, 1955, em­ ploying four controls and eight orally infected turkeys. The eight control birds were sacrificed approximately seven days after the last infected bird expired. Typical symptoms appeared in eight infected turkeys (66-7^); one turkey recovered and seven expired (58.3^ mortality) from the infection. Symptoms did not appear in four of the turkeys inoculated on April 11, 1955; these were sacrificed thirty-four days after inoculation. McKay and Morehouse (1947) reported 8U^ mortality in the turkeys used in their experiments. The oral method of inoculation used by Swales (1950) showed 61-78.5 per cent mortality. The low per cent of infectivity in this second 91 experiment may be due to the age of the H« gallinae ova, or the effect of refrigeration on the infective material. The embryon at ed H. gal1 i nae ova were stored in normal saline and refrigerated during the four months between these two experiments. Symptoms appeared between nine and twenty-one days after infection. The first symptom observed was sulfur- colored feces, followed by drowsiness, drooping of the wings and tail, and anorexia. Infected turkeys began los­ ing weight between the 12th to 21st day after inoculation. Death occurred between the 15th to 27th day. All control turkeys gained weight throughout the experiment (Plate XXVIII). The average redal temperature of the control birds was 106.6° F. The temperature of infected turkeys rose, on the average, to 108.2° F between the second and sixth days before death, and decreased to an average temperature of 103.7° F on the day of death (Plate X X I X ). McGuire and Cavett (1952) reported a 39.7° C (103.6° F) temperature of infected birds during the period of severe clinical symptoms. The temperature prior to this period was reported as 41.2° C (106.2° F). The bird which showed signs of recovering from the in­ fection lost weight between the 12th and IVth days after infection and then steadily gained weight until it was sacrificed. The temperature increased to 1U8° F on the 15th day after infection and decreased to 106° F at the time of exsanguination. 92 The four turkeys inoculated with H. gallinae ova, hut which did not develop enterohepatitis revealed no symptoms. PLATE 3tXVIII 2500 WEIGHT CHANGES 2000 500 ‘, ^ iV ,g *i" B 9 & .k 9 ■ïlt- 120 Plate XLl* Parabronchial edema. Note congestion (A) and area of focal lymphocytic Infiltration (B). 170x a PLATE XLI 121 \ 122 Plate XLII# Heterophils (A) and macrophages (B) in exudate of the lung. lOCOx PLATE XLII I . 125 T ^ 6. ..JT # $ # y - v:i "k _ . . ^ ' y ’• . 1 O .• ^ J * i ' . • * - *•• * • - ; * * ' ^\ -k 122 a Plate XLII. Heterophils (A) and macrophages (B) in exudate of the l u ng. 100Ox 123 PLATE XLII e # # A # %# % # ' # t 4 *■ C ( # # » #• r* % » e # * % # ^ g. # %# % # # ■i # # 124 Kidney The lesions in the kidney were similar to those ob­ served in the ceca and liver. Congestion and hemorrhage were apparent in circumscribed areas. Lymphocytes infil­ trated Into the areas of caseation necrosis. Giant cells and parasites were observed in the necrotic areas (Plate XLIII). Spleen The spleen revealed lesions similar to these of other organs. Protozoa "nests** were observed and were surrounded by lymphocytes (Plate XLIV). The macrophages were distribu­ ted more diffusely throughout the spleen than in other or­ gans. Protozoans were numerous in blood vessels (Plate XIV). Pancreas Congestion was observed in blood vessels of the pan­ creas. The mesentery was inflamed, and edema with a sero- celluiar exudate was observed (Plate XLVI). Necrosis was absent and parasites could not be demonstrated in the sections examined. Heart An epicerditis characterized by edema, and a serocellular exudate was observed around the heart. The epi- cardium was greatly thickened in places (Plate XLVII). 125 Plate XLIII. Giant cells (a ) and protozoa nests (J3j in kidney medulla. 90Ox PLATE XLIII 'm 126 I p - % ^3 % |s» I I I t 4 # i 125 Plate XLIII* Giant cells (A.) and protozoa nests (B) in kidney medulla. 900x a 126 PLATE XLIII % 127 Plats XLIV* Giant cells (A) and protozoa in nests (B) in spleen. lllOx 128 PLATE XLIV (% VU » w rw 4 # 4# 127 a plats XLIV. Giant cells (A) and protozoa in nests (B) in spleen. lllOx 128 PLATE XLIV 4 4 \ 129 plate XI;V- Protozoa (A ) in Dlood vessel (B) of the spleen. 230x 130 PLATE XLV Mi t •t 129 Plate XI.V. Protozoa (a) in blood vessel (B) of the spleen 330x a PLATE XLV A 130 131 Plate XLVI- Inflammation (a ) and sero-cellular exudate (B) of the mesentery around the pancreas (G). Note congestion of blood vessels in the mesentery (L). 275x 132 PLATE XLVI ■ ' ■ ■ ■ l.vr *» * I _. %. - / - j ,. , V à * » » 131 a Plate XLVI- Inf lamination (a ) and sero-cellular exudate of the mesentery around the pancreas (C). Note congestion of blood vessels in the mesentety [D). 275x g. 132 PLATE XLVI ;tv•* ' • • '% ",.V• ^ V-'•-•a ^'Vl V ' ' ”*' ' ' '% :. -''':■ •/' ( ' . -r V '♦ ■ ■ *'.->•.* . ..'. ' / 133 Plaxe XLVII. Epicarditis. Note xne thickened epicardium (A] ^ myocaraiuiii (Bj. 40ux 154 PLATE XLVII Wÿ" f \'4Â' s % 133 Plate XLVII. Lplcard.itis. Note tne tnicjfecened epicardium 1A) ocaraiuiu (ü) . 4uux a PLATS XLVII 134 135 In summary the histomonas organism was observed in the cecum, liver, kidney and spleen. The protozoa occurred in nests or within giant cells. were apparent. frequently Vascular changes The inflammation was of an acute type as characterized by the infiltration of lymphocytes* The lesions in the heart, pancreas, and lungs probably were secondary. these organs. The parasite could not be demonstrated in 13b SUMMARY 1. The normal histology of the lungs, heart, kidney, pancreas, spleen, liver, and intestinal tract of turkey poults was studied* 2* The following histological differences between the chicken and turkey were observed: a* Lsophageal glands opened into the crypts of tonsil-like lymph nodules near the junction between the esophagus and proventriculus. b. The muscularis mucosa, when present, consisted of only one circular layer of smooth muscle. c. üilastic fibers were observed in the connective tissue stroma separating the parabronchi of the lungs. 3. The normal hematology of turkeys was studied and compared with the results of other investigators. 4. Light of the twelve turkeys Inoculated with embry- onated H. gallinae ova revealed the following symptoms of a histomonas infection: a. Decrease in the total red blood cell count, hemoglobin, and white blood cell count. b. The heterophils increased while the lympho­ cytes decreased. c. The temperature rose during the infection and was sub—normal at the time of death. 137 5. Typical gross lesions produced by H# meleagridis were observed in the liver and ceca of the infected turkeys. Gross lesions were also observed in the spleen, kidney, and lungs. 6. Microscopic lesions, in which the parasite could be demonstrated were observed in the ceca, liver, kidney and spleen. These lesions were characterized by hyperemia, hemorrhage, lymphocytic infiltration, the presence of giant cells, necrosis, and usually a serous exudate. 7. The lung, pancreas, and heart exhibited lesions characterized by îiyperemia and a sero-cellular exudate. Lymphocytic infiltration was observed in the lungs. sites were not demonstrated in the lung, pancreas or heart. Para­ 136 LITER AT URL CITED Allen, L. A. 1936. A Pentatrichomonas associated with certain cases of enterohepatitis or "blackhead" of poultry. Trans. Am. Micro. See. 55: 315-322. Allen, L. A* 1941. Macroscopic differentiation of lesions of histomoniasis and trichomoniasis in turKeys. Am. J. Vet. Res. 2: 214-217. Baker, A. D. 1933. Some observations on the development of the caecal worm, Heterakis gallinae (Gmelin, 1V9U) Freeborn, 1923, in domestic fowl. Sci. Agric. 13; 356-363. Bishop, A- 1938. Hi st omonas meleagridis in domestic fowls (Gallus gallusIV Cultivation and experimental in­ fection. Parasitai. 30: 161-194. 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