Veterinary obstetrics : a compendium for the use of students and practitioners

Front matter

22101893260 f ^

Med

.A COMPENDIUM

Preface

In offering this little volume to the Veterinary Profession of America, it is not my desire to encourage the student in the neglect of the more voluminous works on Veterinary Obstetrics, but more -with the idea of aiding him, when time is an object, in reviewing his studies on the subject. It is with the hope, also, that it may be of service to the busy obstetrician, in refreshing his memory when quick reference is required, or when larger works may be inaccessible.

In the preparation of this compendium, the following literature has been consulted, and, in several of the sections, somewhat freely quoted : “ Fleming’s Obstetrics,” “ Chauveau’s Comparative Anatomy’* (Fleming), “Vade Mecum of Equine Anatomy” (Liautard), Friedberger & Frohner’s “Pathology and Therapeutics of the Domestic Animals,” “ Moller’s Surgery,” “Journal of Comparative Pathology and Therapeutics” (McFadyean), articles in published reports of the U. S. Department of Agriculture (Law); and I am much indebted to my friend Mr. John Renfrew, M.R.C.V.S., of Glasgow, Scotland, for numerous and copious notes. I am under many obligations to Dr. George Fleming, C.B., of Higher Leigh, Combe Martin, North Devon, England, for his kindness in granting permission to use the cuts (from

VI

PREFACE.

his valuable work on obstetrics) for the purpose of illustrating the text.

The printer and publisher, William R. Jenkins, New York City, deserves my thanks, not only for the style and neatness with which he has executed his work, but for the promptness with which he has facilitated the reading of the proof, etc.

Should this little work seem to fill a gap, and find a modest but useful place in our veterinary literature, I will feel fully repaid for any time or trouble expended.

W. H. DALRYMPLE.

Baton Rouge, Louisiana, U.S.A.

Chapter I. Page

Preface v

Anatomy — Female Organs Concerned in Generation and

Parturition 7

The Pelvis 7

The Os Innominatum or Coxa. 7

Ilium 8

Ischium 9

Pubis 9

The Sacrum... 10

The Coccyx. 11

The differences in the pelvic bones of other animals 11

The Cow 11

The Sheep and Goat 12

The Bitch and Cat 12

The Hog 13

Pelvic Articulations 13

Differences in other animals 14

The Cow 14

The Sheep and Goat 14

The Pig 14

The Bitch and Cat 14

Pelvic Cavity 15

Pelvic Inlet 15

Pelvic Outlet 16

Differences 16

The Cow 16

The Sheep and Goat 17

The Pig 17

The Bitch and Cat 18

The Vulva 18

The Clitoris 18

The Hymen 19

The Meatus Urinarius 20

The Vagina 21

vii

VU1 TABLE OF CONTENTS

PAGE

The Uterus 22

Fallopian Tubes 23

The Ovaries 24

Mammary Glands 24

In the Cow 25

In Small Ruminants 26

In the Pig. . 26

In the Bitch 26

CHAPTER II. Age of Puberty 27

In the Cow 27

In the Mare 28

Period of CEstrum 29

In the Mare 29

In the Cow 29

In the Bitch 29

In the Ewe 29

Period of Gestation 31

In the Different Animals 33

Foetal Envelopes 33

The Chorion 33

The Amnion 33

The Allantois 34

Umbilical Vesicle 36

Placental Circulation 36, 39

Umbilical Cord 38

Symptoms of Pregnancy and Parturition 40

CHAPTER VI. Causes of Foetal Dystokia 60

Causes of Maternal Dystokia 60

Mal-Presentations of Foetus 61

Anterior-Presentations 61

Vertebro-Pubic 61

Vertebro-Iliac 62

Vertebro-Sacral (fore legs over neck) 63

Vertebro-Sacral (fore legs flexed at fetlocks with head normal). 63

Vertebro-Sacral (fore limbs flexed at knees) 64

Vertebro-Sacral (head normal, but fore limbs back under

body) 65

Vertebro-Sacral (head bent downwards) 66

Vertebro-Sacral (head turned to one side) 68

Vertebro-Sacral (head bent backwards and upwards) 69

Vertebro-Sacral (obstruction due to hind limbs) 69

Vertebro-Sacral (all four feet presented) 70

Posterior-Presentations - 70

Lumbo-Sacral 70

Lumbo-Sacral (hind limbs flexed at fetlocks) 71

Lumbo-Sacral (hocks flexed) 71

Lumbo Pubic 73

Thigh and Croup '. 73

Sterno-Abdominal • 75

Dorso-Lumbar 76

X

CHAPTER X. Deformity of Pelvis 90

Fractures 90

Exostoses 90

Hernia of Uterus 92

Deviation of Uterus 93

Torsion of Uterus 94

Tumors 97

Hernia of the Bladder 97

Spasm of Os-Uteri 97

Induration of Os-Uteri 99

Scirrhous Chorion 99

Persistent Hymen 99

Want of Muscular Power to Expel Foetus 100

CHAPTER XI. Some Accidents Following Paturition 101

Post-Partum Hemorrhage 101

Retention of Fcetal Membranes 102

Inversion of Uterus 104

Metrotomy no

Inversion of Vagina m

Inversion of Bladder nx

TABLE OF CONTENTS XI

Chapter XII. Page

Some Pathological Conditions Following Parturition 113

Vaginitis 113

Metritis 113

Leucorrhcea 115

Parturient Apoplexy 116

Eclampsia . 122

Parturient Paralysis (post-partum) 124

Phlegmasia Dolens 124

Parturient Laminitis 126

CHAPTER XIII. Diseases of the Mammary Glands 127

Wounds and Bruises 127

Mastitis or Mammitis 128

Phlegmonous Mastitis 129

Parenchymatous Inflammation 130

Mastitis Catarrhalis 130

Mastitis Apostematosa 13 1

Mastitis Gangrenosa 133

Stenosis of Mammary Duct 134

Mastitis Chronica 135

Tumors of the Udder 136

Polypi 136

Chapped or Fissured Teats 136

Agalactia or Agalorrhoea 137

CHAPTER XIV. Milk, Its Composition, Etc 138

Anamolies of Secretion 138

Watery Milk 138

Fat Milk 139

Alterations in Milk Due to External Influences 139

Curdled Milk *139

Milk Which Does Not Produce Butter 140

Putrid Milk 140

Filamentous Milk 140

Blue Milk 140

Some Other Anomalies 141

Xll

TABLE OF CONTENTS

Chapter XV. Page

Diseases and Abnormalities of the Young Animal 142

Asphyxia 142

Umbilical Hemorrhage 143

Persistent Urachus 143

Umbilical Hernia 144

Acquired Hernia, Causes of 145

CEdema of Umbilicus 146

Omphalitis 147

Arthritis 149

Constipation 151

Gastro-Intestinal Catarrh 151

Dysentery 157

Cyanosis 157

Eclampsia 157

Tetanus Neonatorum 157

Some Other Conditions Occasionally Met With 158

LIST OF ILLUSTRATIONS.

FIG. PAGE

1. Pelvis of Mare 8

2. Pelvis of Cow ii

3. Pelvis of Sheep 12

4. Lateral Ligaments of Sacrum and Pelvis 13

5. Ligaments of Lumbar Vertebras, Sacrum and Pelvis 14

6. Diagram of Mare’s Pelvic Axis 15

7. Inlet of Mare’s Pelvis 16

8. Inlet of Cow’s Pelvis 17

9. Generative Organs of Mare in situ 21

10. Ovary Opened Vertically 24

11. Graafian Vesicles and Ovum 24

12. Section of Udder of Cow 25

13. Section of Cow’s Teat 26

14. Foetus of Mare and its Envelopes 32

15. Chorion of Mare at Mid-term (Inflated) 34

16. Foetal Membranes of Cow at Mid-term 35

17. Maternal and Foetal Cotyledons of Cow 37

18. Foetal Circulation : Advanced Period 39

19. Normal Position of Foetus in Mare (third stage) 43

21. Jointed Repeller 62

22. Vertebro-Sacral Position (fore-limbs flexed at knees) 64

23. Anterior Presentation (extreme downward deviation of head) 67

24. Short Blunt Crotchet 67

25. Long Pointed Crotchet 68

26. Vertebro-Sacral Position (deviation of head upwards and back-

wards) 69

27. Lumbo-Sacral Position 71

28. Hock Presentation: Hock Corded 72

29. Thigh and Croup Presentation : Thigh Corded 73

30. Gunther’s Curved Porte-Cord and Blunt Crotchet 74

31. Sterno-Abdominal Presentation 75

32. Dorso-Lumbar Presentation 77

33. Straight Embryotom 80

34. Cartwright’s Subcutaneous Spatula 8r

xiii

XIV

Index

FIG. PAGE

35. Sysomian Monstrosity: Dicephalus bicollis (Gurlt) 86

36. Ectopia Cordis : Schistocormus fissisternalis 87

37. Skull of Hydrocephalic Calf 88

38. Anasarcus Foetal Calf 89

39. Pelvic Exostosis 91

. 40. Uterine Hernia 92

41. Right Uterine Torsion : Manipulation 94

42. Left Uterine Torsion : Manipulation 94

43. Left Uterine Torsion in situ 95

44. Barnes’ Uterine Dilator 98

45. Pad Pessary. 106

46. Ring Pessary 107

47. Zundel’s Labial Sutures 107

48. Leather Truss 108

49. Renault’s Truss 108

50. Lund’s Truss Applied 109

51. Ring Teat Syphon 128

Chapter I. ANATOMY

FEMALE ORGANS CONCERNED IN GENERATION AND

PARTURITION :

The Pelvis , Vulva , Clitoris , Vagina , Uterus, Fallopian Tubes, Ovaries and Mammae .

The Pelvis.

This cavity is formed of bony and ligamentous walls, and contains a portion of the genito-urinary apparatus, as well as the terminal portion of the alimentary canal. It is situated towards the end of the spine, and is supported by the hinder extremities, with which it is connected by joints and muscles. It is composed of three principal bones — the two ossa innominata , or coxae , and the sacriim , and to some extent of the coccygeal vertebrae .

OS INNOMINATUM.

The os innominatum, or coxa , one on each side, is a flat bone, expanded at either extremity, somewhat constricted in the middle, and curved in two different directions. At its middle it has a wide and deep articular depression surrounded by a high rim, — the acetabulum or cotyloid cavity, — in which the articular head of the femur is lodged and moves. Above this cavity there is a roughened thin ridge, the supra-cotyloicl crest or ischiatic spine, into

VETERINARY OBSTETRICS.

which the sacro-sciatic ligament is fixed. Below the cavity, and inclining inwards, is a large circular opening, occupied by the obturator muscles and known as the foramen ovale , or obturator foramen. The two ossa innominata are united in the middle line inferiorly and posteriorly by a solid suture — the symphysis pubis, or ischio-p^lbic symphysis. Above they articulate with the sacrum.

Fig. i.

Pelvis of the Mare.

A, Ilium; B, Pubis; C, Ischium; D, Foramen Ovale; E, Tuberosity of the

Ischium; F, Cotyloid Cavity.

The os innominatum is composed of three portions uniting at the acetabulum, and have received the names : the ilium , ischium , and pubis.

The ilium , hip , or haunch , is the largest of the three bones. It is irregularly triangular in shape, and is directed obliquely downwards, inwards and backwards, and has two faces, three borders, and three angles. The external face presents the external iliac fossa ; the internal face the iliac surface, and an auricular

ANATOMY.

facet for articulation with the sacrum. The anterior border or crest is concave ; the external has a medullary foramen and vascular grooves ; the internal forms the great sciatic notch. The external angle or point of the hip has four tuberosities for muscular attachment. The internal, or antero-internal angle is a rough tuberosity curving upwards and backwards, forming, with the corresponding portion of the opposite ilium, the summit of the croup. The posterior or cotyloid angle offers a facet for the cotyloid cavity, the supra-cotyloid crest, the ilio-pectineal eminence, and some muscular imprints.

The ischium is the most posterior of the three bones. It is flat and irregularly quadrilateral in shape, and is composed of a solid portion (the body) and a narrow part (the neck). It is divided into two faces, four borders, and four angles. The upper face is smooth, and forms the floor of the pelvic cavity ; the inferior face is roughened for the attachment of muscles, and presents the ischial crest. The anterior border forms the obturator foramen, the external the small sciatic notch ; the posterior forms the ischial arch, while the internal is articular. The anteroexternal or cotyloid angle presents a diarthrodial facet, and the posterior extremity of the supra-cotyloid crest ; the antero-internal angle is articulated with the pubis ; the postero-external forms the ischial tuberosity ; and the postero-internal articulates with that of the opposite side.

The pubis is the smallest of the three bones, and is situated between the ilium and ischium. It is divided

IO

VETERINARY OBSTETRICS.

into two faces, three borders, and three angles. The superior face is smooth and concave ; the inferior has a large groove for the pubio-femoral ligament. The anterior border is thin and rough, the posterior thick and concave, and assists in forming the obturator foramen ; the internal border is thick and articular. The external or cotyloid angle forms the bottom of the cotyloid cavity ; the internal and posterior angles are articular.

The sacrum results from the fusion of five vertebrae into a single, voluminous, pyramidal or triangular mass. It may be said to terminate the vertebral spine posteriorly. It encloses the pelvic cavity above, and articulates in front with the last lumbar vertebra, behind with the first coccygeal, and laterally with the ossa innominata . It is divided into two faces, two borders, a base, an apex, and a central canal. The superior face presents the spinous processes forming the sacral spine, bent backwards and diminishing in length posteriorly; it offers on each side the four supra-sacral foramina. The inferior face is smooth and shows the lines of separation of the vertebrae, and on each side the four sub-sacral foramina. The borders are thick and concave, rough posteriorly, having forward a broad, rough auricular surface to articulate with the ossa innominata. The base offers, on the median line, the anterior orifice of the sacral canal, and the anterior articular head of the body of the first sacral vertebra ; on the sides, the articular processes and the anterior notches of that vertebra, and the outside, the two large facets for articulation with the last lumbar vertebra.

ANATOMY.

1 1

The apex presents the posterior opening of the sacral canal, the posterior articular cavity, the body of the last sacral vertebra, the vestiges of the articular processes, and the posterior notches of that vertebra. The sacral canal is a part of the rachidian canal, triangular, and diminishes in width posteriorly.

The coccyx is composed of from fifteen to eighteen coccygeal or caudal vertebrae, situated behind the sacrum, the first three of which may be said to belong to the pelvis.

Fig. 2.

Pelvis of the Cow.

A, Ilium; B, Pubis; C, Ischium; D, Foramen Ovale; E, Sciatic Spine;

F, Cotyloid Cavity; G, Tuberosity of the Ischium.

DIFFERENCES OF THE BONES OF THE PELVIS OF OTHER

DOMESTIC ANIMALS.

The coxa in all the domestic animals are more or less horizontal, and the ilium has a vertical direction.

In the Cow, the space between the coxae is no greater before than behind ; they are less solid and

VETERINARY OBSTETRICS.

voluminous than in the mare. The iliac concavity not so wide, and is rr Ae vertical than in the mare.

The ischium is thinner, but has a wider surface, is more curved from before to behind, and from side to side ; while the ischiatic spine is prominent and thin. There are three tuberosities on the postero-external angle.

Th z pubis is wide and thin; the upper face is very concave, and on its inferior face it has no channel. The foramen ovale is large. There is earlier ossification of the symphysis than in the mare.

The sacrum is longer, more curved and voluminous.

Fig. 3.

Pelvis of the Sheep.

A, Ilium; B, Pubis; C, Ischium; D, Foramen Ovale; E, Cotyloid Cavity.

The caudal vertebrae are stronger and more tuberous ; sixteen to twenty in number.

The pelvis of the Sheep and Goat resembles that of the Cow, although, on the whole, it is more horizontal and longer.

In the Bitch and Cat, the lateral diameter is greater before than behind. The ilium is almost

ANATOMY.

vertical. The sacrum is somewhat quadrangular; is composed of three bones which are consolidated at an early age. Only three vertebral foramina.

The bones of the coccyx are strong and tuberous, the first five or six being as perfect as the true vertebral bones.

The pelvis of the Hog (Pig) resembles that of the Sheep. The iliac crest is convex. The pubis is narrow, and the ischium has a tuberous prominence. The sacrum is composed of four vertebrae, which do not become entirely consolidated for a length of time.

Fig. 4.

Lateral Ligaments of the Sacrum and Pelvis.

a, Superior Sacro-iliac Ligament ; b, Sacral Ligament ; c, Lateral Sacro-iliac Ligament; d, Sacro-sciatic Ligament; e, Small Sciatic Notch; f, Great Sciatic Notch .

The spinous processes are absent. The spinal canal is open above, due to the neural arch being deficient on each side.

THE PELVIC ARTICULATIONS.

Five in number: sacro-lumbar, two sacro-iliac, the ischio-pubic symphysis, the sacro-coccygeal articulations and the ilio-sacral and sacro-sciatic ligaments.

VETERINARY OBSTETRICS.

With the exception of the equine species, the sacrum is joined to the last lumbar vertebra by three diarthrodial surfaces only — the head of the body and two transverse processes.

The ischio-pubic symphysis in the Cow is considerably longer than in the Mare and not rectilinear; ossification of the symphysis is less complete, and takes place much later than in the Mare.

Fig. 5.

Ligaments of the Lumbar Vertebrae, Sacrum and Pelvis.

(Seen from below.)

a, Intertransverse Ligament of the Lumbar Vertebrae ; b, Capsular Ligament of the Spinous Process of the Fifth and Sixth Lumbar Vertebrae; c, Capsular Ligament of the Sacrum; d, Inferior Sacro-iliac Ligament; e, Obturator Ligament; f. Transverse Ligament of the Ischio-pubic Symphysis.

In the Sheep and Goat, the ischio-pubic symphysis is rectilinear. Ossification very late in life, and almost never in those animals which have had many young. These remarks apply also to the Pig.

In the Bitch and Cat, the symphysis rarely ossifies. The sacro-sciatic ligament is attached superiorly to the lateral borders of the transverse processes of the

ANATOMY.

*5 sacrum and first two or three coccygeal vertebrae; inferiorly, to the superior ischiatic spine and tuberosity of the ischium.

The Mare’s pelvis represents a somewhat cone-shaped cavity at the posterior part of the trunk continuing the abdominal cavity. It has an internal and an external surface, and two openings.

The anterior opening is termed the inlet of the pelvis, by which the foetus enters the pelvic cavity. The posterior is known as the outlet or recto-urethral opening.

Fig. 6.

Diagram of the Mare’s Pelvic Axis.

A, Inlet ; B, Outlet.,

The diameters of the inlet are generally recognized as two : The supero-inferior or sacro-pubic, which is the width between the sacro-vertebral angle and the symphysis pubis. It varies with the size of the animal, but is usually between eight and ten inches. The transverse or bis-iliac diameter is the distance between one ilio-pectineal crest and the other. From seven to nine inches.

i6

VETERINARY OBSTETRICS.

The outlet of the Mare’s pelvis is limited above by the apex of the sacrum and the base of the coccyx, and below by the ischial arch formed by the junction of the two ischia ; and laterally by the upper surface of the ischia, and posterior border of the sacro-sciatic ligaments. The diameters are usually less than those of the inlet.

The pelvis of the Cow is longer than that of the Mare, and not so vertical ; the ischio-pubic symphysis is longer, and is very curved, making the floor concave

Fig. 7.

Inlet of the Pelvis of the Mare. a b, Supero-inferior, or Sacro-pubic Diameter; c d, Superior Bis-iliac Diameter; ef, Inferior Bis-iliac Diameter; e i,fh, Oblique, Ilio-sacral or Sacro-iliac Diameters ; J K, Middle Diameter.

in every direction. Comparatively speaking, the bony structure is altogether more extensive. The' sacral surface is more concave, and the sacro-sciatic ligaments, although narrower, are longer. Compared with its height, the Cow’s pelvis is less wide.

The inlet being more oblique than in the Mare, the diameters are very unequal.

ANATOMY.

I 7

The diameters of the outlet are more equal, being about those of the transverse diameter of the inlet. The cavity is more cylindrical and less conical than that of the Mare.

In the Sheep and Goat, ossification occurring at a much later period, allows of the pelvic cavity being increased during parturition, and permits of the act being performed with fewer difficulties in these animals.

In the Pig, the general conformation of the pelvis

Fig. 8.

Inlet of the Cow’s Pelvis.

a b, Supero-inferior, or Sacro-pubic Diameter; c d, Superior Bis-iliac Diameter; e f, Inferior Bis-iliac Diameter; ei,fh, Oblique, Ilio-sacral or Sacro-iliac Diameters.

is not unlike that of ruminants. The promontory of the sacrum is more salient, the canal longer, the plane of its anterior circumference more oblique, and the direction of the ischio-pubic symphysis perfectly rectilinear. The cavity is very large in proportion to the size of the young at birth, hence accidents are rare during parturition. , i8

VETERINARY OBSTETRICS.

In the Bitch and Cat, the promontory of the sacrum is still more marked than in the Pig, which diminishes notably the inlet of the pelvis; the direction of the symphysis is rectilinear, and the general outline of the cavity is nearly cylindrical, although the inlet is larger below than above. The narrowest part of the canal is immediately above the obturator foramen, where the ischium is wide and shallow, and rises abruptly to almost a right angle.

The Vulva.

This is the most external portion of the female reproductory organs, and presents posteriorly an opening situated vertically under the rectum, from which organ it is separated by a narrow space — the perineum.

The labise form the lateral boundaries, and, in the normal condition of the parts, are in contact with each other. They are lined on their internal surface with mucous membrane ; externally with a very smooth skin devoid of hair.

The cavity of the vulva varies in length in the cow and mare, from six to ten inches. At parturition, the walls become separated to allow of the escape of the foetus.

The cavity contains several organs accessory to reproduction, which we will now notice separately.

The Clitoris.

This organ is situated on the inferior commissure of the vulva, and corresponds to the corpus cavernosum

ANATOMY.

l9 of the male. It is firmly held in position by a fold of ligamentous tissue, to the floor of the Vulva. It is composed principally of erectile tissue, which tissue becomes congested at the period of oestrum, rut, or heat. The clitoris is covered, on its free surface, with a pigmented membrane which is arranged in folds, and is very highly endowed with sensibility ; this membrane being believed to perform an important function in the act of copulation.

The Hymen.

This is a fold of mucous membrane which more or less completely separates the vulva from the vagina, and stretches across the passage at the division of these two organs. It is a very delicate mucous structure, and for a long time it was believed that this membrane was normally complete, and was only ruptured at the first act of copulation, and its presence or absence was looked upon as a sign of virginity. Even to this day some authorities hold that laceration of this membrane denotes the absence of virginity. This, however, is a mistake in all animals, as some human females have been examined who never had coition, and this membrane was represented simply by a small band; while others again have been examined and this membrane found complete after the female had given birth to several children.

In our subjects, the hymen is often well developed in Fillies, but is often absent, or only rudimentary, in Heifers

VETERINARY OBSTETRICS.

The Meatus Urinarius.

This is the external opening of the female urethra, and is found on the floor of the vulva about five inches from its external opening, but the distance varies in different animals. The opening is guarded by a fold of mucous membrane attached to the floor and sides of the vulva, having its free border placed in a backward direction. This membrane is believed to prevent the passage of urine into the vagina. In the Cow, immediately behind the opening of the meatus, there is a small fossa about half an inch in depth, also guarded by a valve, the function of which is doubtful, but it frequently causes difficulty in passing the catheter in that animal, being mistaken for the meatus.

About one inch from the external opening of the vulva in the Cow, are situated some almond-shaped conglomerate glands whose ducts unite to form a sinus, by which the secretion from the glands is thrown into the vulva about half an inch, from the external border. These glands are only active at the period of oestrum, and are believed to secrete a fluid having a characteristic odor, which seems to attract the opposite sex at this period.

In the female Pig, there is no vulvo-vaginal membrane guarding the opening of the meatus, and in this animal the clitoris is only rudimentary, and often absent altogether.

In the female Cat, there is in the clitoris a small cartilaginous body which has not been seen in any other of the domestic animals, and has been believed

ANATOMY.

by some to be the means of prolonging the act of copulation in this feline.

In the female Sheep, the hymen is often represented by a delicate band stretching obliquely across the cavity, and even this is sometimes absent.

The Vagina.

This is the cavity which connects the vulva and uterus. It varies in length from nine to twelve inches,

Fig. 9.

The Generative Organs of the Mare in situ.

1, Body of the Uterus; 2, 2, Cornua of the Uterus; 3, Vagina; 4, Bladder; 5, Rectum; 6, Sphincter of the Anus; 7, Constrictor Muscle of the Vulva; 8, Bulb of the Vagina; 9, Ovary and Fimbriated Body; 10, Fallopian Tubes; 11, Kidney; 12, 12, Broad Ligament.

and the membrane of its walls is very loosely attached to the sub-mucous tissue. In the normal condition this membrane is thrown into folds, which in the Cow are always in a transverse direction, and in the Mare

VETERINARY OBSTETRICS.

are longitudinal. These folds assist in enlarging the cavity at the period of parturition, and become obliterated then.

Anteriorly the vagina receives into it the cervix or neck of the uterus, which is projected some distance into its cavity, and has its walls thrown into a number of folds or ridges.

In the walls of the vagina in the Cow, and sometimes also in the Mare, are found the canals of Gaertner, which are believed to perform a function in foetal life. By one extremity these canals open into the vulva at the lateral aspect of the meatus, and by their other extremity they terminate in a blind cavity in the walls of the uterus.

The Uterus.

This is the most important female organ of reproduction, and is the cavity in which the healthy or normal development of the foetus takes place, and where it is retained and nourished until it is able to maintain an independent existence outside of the body. This organ is divided into a body and two horns. The horns are situated anteriorly, and are slightly curved on themselves, presenting inferiorly a concave curvature in the Cow, and a convex one in the Mare. The internal cavity of the uterus, like the external, is also divided into a body and two horns, but in the non-pregnant animal, the horns are only very rudimentary, and become enlarged to accommodate the foetus after impregnation and growth take place. The walls of the uterus and horns are formed of three distinct layers.

ANATOMY.

viz.: an internal, mucous • a middle, muscular; and an external, serous layer. The central or muscular layer has its fibres arranged in different directions, some longitudinal and others circular. The muscular fibres

o

become considerably hypertrophied in the pregnant state, and by their contractions are largely responsible for the expulsion of the foetus.

In the Cow, the mucous membrane of the uterus, and more especially that of the horns, is studded with a great many processes, resembling very much the appearance of the half of a large English walnut. These processes are called the maternal cotyledons. They contact with opposing surfaces on the foetal membrane, and by means of this connection, circulation between the foetus and parent takes place in the uterus.

In the Sheep and the Goat, these cotyledons are concave on their free surfaces, and in the Mare they are entirely absent, the connection being diffuse.

The uterus is held in position to the sub-lumbar region, by two broad ligaments which are attached to the superior border of the horns, and between the folds of these are found the Fallopian tubes.

Fallopian Tubes.

Two in number, are situated between the folds and near to the anterior border of the broad ligaments. By their posterior extremities, they communicate with the uterine horn of their own side, and by their anterior extremities, indirectly with the ovary.

VETERINARY OBSTETRICS.

The Ovaries.

These organs, two in number, resemble very much in shape and size the testes of male animals, but are always comparatively smaller. They are situated in the sub-lumbar region, being suspended at the anterior extremity by the broad ligament. Each ovary consists

Fig. io.

Ovary Opened Vertically.

a, a, b , b, Graafian Vesicles at different stages of development.

of a serous covering externally, the tunic or covering proper of the ovary, a number of Graafian vesicles, each of which contains a number of ova, and on the presence of these vesicles and the ova the life of the future animal depends.

Fig. ii.

Graafian Vesicle and Ovum.

l

Mammary Glands or Mammae.

The mammae of the Mare are situated in the inguinal region, and are formed of two hemispherical

ANATOMY.

masses, distinct from each other, and having in their centre the teat, nipple, or mammillae. They are composed of a yellow elastic fibrous envelope, glandular tissue made up of acini, clustered in groups around the lactiferous ducts, which by their union open into the galactophorous sinuses, from which arise the true excretory canals of the glands.

Section of Udder of Cow.

a, Anterior Quarter; b, Posterior Quarter; g, Septum between the Quarters; c, c, Section of the Lactiferous Ducts; d, d, Lactiferous Sinus or Milk Cistern; e, e, Orifice of the Teat; f, Large Lymph Gland in the Posterior Quarter.

In the Cow the mammae are also inguinal, and are composed of two symmetrical halves placed one against the other. Each half is again divided into two distinct glands, each with its own teat, so that the vessel consists of four mammae and four teats ; behind this there may be two small rudimentary teats. In the centre of each quarter, just at the base of the teat, is a large galactophorous sinus, the general receptacle of all the lactiferous conduits.

VETERINARY OBSTETRICS.

In the small ruminants there are two mammae and two teats, constructed like those of the Cow.

Section of the Cow’s Teat.

a, a, Principal Lactiferous Ducts; b, Lactiferous Sinus; c, c, Acini; d, Elastic or Dartoid Tissue of the Teat; e, Orifice of the Teat.