Fetal Complications of Gestation in the Buffalo: Etiology, Antenatal Diagnosis and Management

Fetal problems occurring during pregnancy in the buffalo include fetal death, (abortion, mummification, maceration), fetal developmental abnormalities (fetal monsters, fetal dropsical conditions) and ectopic pregnancies [1]. The etiology of most of these conditions is poorly described. Although extensively studied in human pregnancies, the data are scant on the ultrasonographic manifestations of any anomaly in the last trimester of pregnancy [2]. The objective of antenatal fetal diagnosis for abnormalities is to offer termination of the pregnancy in humans, for diseases that are potentially fatal and for which there is still no adequate or specific therapy. Antenatal fetal diagnostic approaches in humans include ultrasonography, magnetic resonance imaging, chorionic villus sampling, amniocentesis and fetal blood sampling [3]. In cattle and sheep, data on approaches to detect fetal well-being has been generated during the last few years [2,4-10] for establishment of normal fetal parameters [10] and because of increased incidence of fetal disorders, with the use of assisted reproductive technologies. Similar conditions are not known for the buffalo and because of its deep capacious abdomen, data generated in cattle are less likely to be useful. Some data on the ultrasonographic evaluations of fetal amniotic vesicle diameter (AVD), crown rump length (CRL) and biparietal diameter (BPD) [11] or the combined thickness of uterus and placenta (CTUP) throughout the normal bubaline pregnancy [12] has been generated in recent years. Such evaluations would likely serve as the basis for prediction of pathological pregnancies in the buffalo. The termination of pregnancies with known fetal disorders is still not common in buffalo except under some specific conditions. The continuance of a pregnancy subsequent to fetal death may lead to fetal mummification or maceration which is undesirable and hence must be terminated. Fetal monsters and dropsical conditions are frequently detected at parturition rather than during a pregnancy. The complications of pregnancy are mentioned for etiology, antenatal diagnosis and management in buffaloes.

Incidence

The overall incidence of fetal complications during gestation appears to be low in buffalo, however; the incidence is based on calving data or the proportions of difficult births. Data of an organized Surti buffalo farm from 2001 to July 2011 involving 529 calvings, revealed that the incidence of abortions was 3.96% and 4.53% of the buffalo calves were either born dead or died shortly after birth. There was no case of fetal mummification, fetal dropsy or fetal monster in this study [1]. Previous evaluations in Murrah buffaloes indicated that the overall incidence of abnormal births was around 5% [13,14]. Abortion rates described elsewhere are similar [15]. In our previous study involving 156 cases of dystocia in cattle and buffaloes we recorded nil incidences of fetal complications in the buffalo [16]. In a more recent analysis involving 112 cases of buffalo dystocia (1996 - 2010), we recorded the incidence of fetal dropsical conditions and fetal monsters to be zero in buffaloes [17].

1. Fetal Complications

1.0. Fetal Death

The embryo is termed a fetus from day 45 in cattle when the differentiation and cell organization begins in the bovine developing embryo [17]. The fetus along with its membranes is known as the conceptus. Death of a developing embryo/fetus can occur any time during its uterine life. An embryonic death occurring before day 45 of gestation is considered early embryonic death [18,19] and is considered as infertility. Any fetal death beyond this time is usually considered as abortion. Changes or affections of the fetus during mid or late gestation can result in fetal compromise which would either result in a fetus with altered form, structure or function (fetal monsters, fetal dropsical conditions) but such fetuses may continue to grow to full term. When fetal compromise is extensive, fetal death occurs. A dead fetus is either delivered within 24 to 72 hours of its death (abortion) or may remain in the uterus with subsequent shrinkage or absorption (fetal mummification) or autolysis (fetal maceration) depending upon whether or not the cervix opens [1]. The delivery of a dead fetus depends on the extent of feto-maternal signaling mechanisms operative between the uterus, ovaries and pituitary [20].

1.1. Abortion

Abortion has been defined in a number of ways but the most suitable definition would be "The preterm" (before completion of gestation period) delivery of a dead/live fetus which is incapable of independent life (day 45 to day 260 of gestation) in cattle [1]. Jo and Peeva [21], consider calvings up to 270 days as abortion in the buffalo. Abortion is also defined as the premature expulsion of the fetus and usually occurs because the fetus has died in-utero or lost attachments with the maternal endometrium. Bovine fetuses are usually incapable of independent life when they are delivered before completion of eight months of pregnancy. Fetuses delivered beyond this period are therefore termed "Premature births or deliveries". The causes of abortion in buffaloes and the abortion rates are similar to those in cattle [22] and include physical genetic/chromosomal, nutritional, chemical, drug induced, hormonal, infectious (bacteria, viruses and fungi), or miscellaneous. Nearly all bacteria, viruses and fungi resulting in cattle abortions have been isolated from buffalo [23-26]. An infectious agent may sometimes result in abortion in a large number of animals, or opportunistic bacterial infections may result in sporadic abortions. At other times, a generalized disease in an individual animal may have abortion as an unusual outcome. Antenatal diagnosis of abortion is frequently not possible in large domestic ruminants [1] and investigations are focused on evaluating the cause of abortion from aborted material or fetus/es (Fig. 1).

Figure 1. A five-month aborted buffalo fetus.

Fetal viability or death during advanced pregnancy is classically identified by fetal responses to tactile manipulation via recto-genital palpation in the large domestic ruminants, however; currently fetal viability can be evaluated using hormonal, chemical and ultrasonographic parameters [8]. Sonographic parameters that predict fetal death in cattle include absence of fetal movements or fetal heartbeat [27]. Low concentrations of maternal estrone sulfate or placental proteins, including pregnancy-associated glycoprotein (PAG) and pregnancy-specific protein B-60 (PSPB-60) [8] are other indicators of fetal compromise. When observed by ultrasonography, fetal death is always preceded by a visible reduction of the amount of allantoic fluid and by segregation of the allanto-chorionic membrane from the endometrium [28]. Examination for fetal development or death during pregnancy is not performed routinely, therefore reference curves for normal fetal growth are scarce and there is considerable physiological variation in the normal values [8]. Reports on the use of ultrasonography for fetal well-being monitoring in the buffalo are not available. Once the process of abortion has started, little can be done to stop it. Clinicians often inject a dose of progesterone on complaint of discharge of vaginal mucoid secretions/blood or constant straining in a pregnant buffalo. It is important to mention that such cases should be first examined thoroughly [1]. Vaginal secretions may originate because of vaginitis and sometimes animals’ with such secretions may even attract male animals. Moreover, injecting progesterone parenterally to a female in which the process of abortion has started and the cervix has opened could be harmful, as it delays the delivery of a dead or compromised fetus which is undesirable. This may sometimes even result in fetal maceration. It is therefore suggested to examine animals showing signs of abortion and initiate preventive therapy only if the cervix is closed. When a fetus dies in the uterus, it is usually expelled within 24 - 72 hours of its death [1].

1.2. Fetal Mummification

Fetal death without abortion and without lysis of CL during the end of the first and beginning of the second trimester of gestation in the cow or buffalo results into autolytic changes in the fetus with absorption of placenta and fetal fluids and shrinkage of the uterus and the fetus. This is known as fetal mummification. The cervix is closed in this condition and the fetus is sterile [1]. Since the corpus luteum is intact, the mummified fetus continues to remain in the uterus and the animal remains anestrus. The incidence of fetal mummification is low (0.01%) in buffalo [29]. Fetal death before formation of the fetal bones does not result into mummification as the entire contents may be reabsorbed. One or more mummified fetuses present in the uterus with one or more normal viable fetuses are rarely observed in buffaloes [30-33]. Fetal mummification is haematic in buffaloes [30,31] similar to cattle. In cattle and buffaloes, when the placental caruncles involute after fetal death, hemorrhage occurs between the endometrium and fetal membranes. This imparts reddish-brown color to the fetus and hence the mummification is known as haematic. Mummification occurs in buffaloes of all ages and has been recorded in various breeds [1,17]. The causes of mummification are poorly described, and it is considered that infectious agents like Campylobacter fetus, molds, leptospirosis and BVD-MD virus causing fetal death without abortion may result in mummification in cattle [34]. Because most of these diseases are also known to occur in buffaloes, these can probably have similar consequences in this species [33,35]. Poisoning with toxic plants is a known cause of fetal mummification [36]. Torsion of the fetal umbilical cord can sometimes be a cause of mummification. The condition can be diagnosed during routine pregnancy examination or sometimes when animals are referred for anestrus. Primiparous heifers are sometimes referred to the clinician with a history of regression of the formerly well developing udder [1]. Transrectal palpation reveals a uterus that is devoid of fluids and that is wrapped tightly around a small firm fetus with a bird-like head (Fig. 2). The empty eye sockets (Fig. 2, Fig. 3) are usually readily recognized by palpation [1]. As the fetus mummifies the uterine wall contracts and tightly enclose the conceptus. The longer the condition exists, the dryer, firmer and more leather-like the tissues of the fetus become (Fig. 4, Fig. 5). The uterine wall becomes thick and the animal remains anestrus due to the persistence of the CL. Sonographically the uterine walls are thickened, no non-echogenic fluid is visible, echogenic areas and hyperechogenic bones (Fig. 6) may be seen [37]. Sometimes animals are not referred for long periods and the mummified fetus inside the uterus may be embedded in the uterine wall. A rare case of mummified fetus reaching the perimetrium of the uterus has been seen by the author; a case of fetal mummification along with uterine torsion has been reported in cattle [38].

Figure 2. A mummified buffalo fetus delivered after PG injection.

Figure 3. A mummified buffalo fetus recovered fby cesarean section.

Figure 4. A bubaline mummified fetus recovered by cesarean section. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India).

Figure 5. A mummified fetus recovered manually from the vagina of a buffalo. (Photo courtesy Dr Sanjay Purohit, Editor, Ruminant Science, Mathura, UP, India).

Figure 6. Ultrasound image of a bubaline mummified fetus. The small bird like head is visible.

The therapy for a mummified fetus when diagnosed early, is simple. Drugs that cause CL lysis like estrogens and prostaglandins are helpful in delivery of the mummified fetuses within 48 - 72 hours in buffaloes [39]. Clinicians must re-examine animals that are treated with such treatments, as sometimes the fetus may be lodged in the cervix or vagina [40,41] from where it has to be removed manually. In long standing cases, one or several of the medical therapies like the use of prostaglandins, estrogens, isoxsuprine HCl or ritodrine, may dilate the cervix but fail to deliver the fetus which is tightly adhered to the uterine wall. Such cases continue to evidence anestrus [42].

In such cases, if the uterine horns are suspended in the abdominal cavity ahead of the pelvic brim, the mummy may be removed surgically through laparotomy under paravertebral nerve block. It is, however, not possible to surgically remove a mummified fetus from a uterus that is located largely in the pelvic cavity [1]. When removed surgically, large portions of the uterus have to be incised to remove a long standing mummified fetus deeply embedded in the uterus. Colpotomy and hysterotomy is another technique suggested for removal of mummies in invaluable cows [43,44]. The fertility of an animal after medical removal of a mummified fetus is good because the fetus is largely sterile [45]. However, fertility subsequent to surgical removal of a mummified fetus deeply embedded in the uterus is fair to poor [1].

1.3. Fetal Maceration

Fetal maceration is the disintegration of a fetus that has died after formation of the fetal bones (beyond 4 months of pregnancy in cattle and buffalo) and has failed to abort, although the cervix is open [1]. Although uncommon, the reason for the non-delivery of a dead fetus could be a partially dilated cervix, uterine inertia, or the abnormal presentation of a fairly dry fetus which causes it to be retained in the uterus [34]. Bacterial invasion of the fetus leads to fetal emphysema and maceration (3 to 4 days). There is formation of plenty of (24 - 48 h) pus and the bones of the fetus separate out [29,46]. The animal discharges plenty of foul smelling, reddish gray vulvar discharge (Fig. 7a, Fig. 7b) and strains frequently [47]. Fever and anorexia may develop due to infection. The condition is noticed by the owners when foul smelling pus is discharged by a pregnant animal. Rarely, it may be diagnosed during pregnancy examination. The condition can be diagnosed by the history, finding of a piece of bone lodged in the cervix, rectal palpation (free fetal bones palpable in crepitating pus and doughy thick uterine wall) and ultrasonography (Fig. 8) (finding of hyperechogenic scattered bones in an echogenic or non-echogenic fluid with echogenic floating pus) [37]. The animal should be examined per vaginum and any pieces of bone lodged in the vagina or cervix must be removed manually if the cervix is dilated. Infusion of large quantities of normal saline in the uterus is helpful in expulsion of the pus and bone pieces 24 hrs later [1]. When the cervix is not open, prostaglandins or estrogens can be given to lyse the partially lysed CL and/or increase the uterine contractions [39]. Sufficient lubrication and gentle removal of the bones is necessary. Sometimes, it may require several days for the uterus to be cleared of the entire pus and bones. Supportive therapy with antibiotics, fluid replacement and corticosteroids is indicated in severe cases. Laparohysterotomy to remove the macerated fetus is potentially dangerous and must be considered as a last resort [48,49]. Animals should not be rebred for at least 3 to 4 months after complete removal of a macerated fetus. The prognosis is always poor. Rarely long standing cases may develop peritonitis subsequent to uterine rupture [1] or utero-enteric fistula [47].

Figure 7a. A buffalo from which a macerated fetus (shown below, Fig. 7b) was delivered.

Figure 7b. A bubaline macerated fetus was delivered. The maceration was not complete and only the skin and hooves have disintegrated.

Figure 8. An ultrasound image of a buffalo uterus with complete maceration. Echogenic material (pus) and pieces of bone are visible.

2. Fetal Developmental Abnormalities

2.0. Fetal Monster

A fetal monster is an individual that has undergone severe damage during pregnancy without death usually changing its appearance [1]. The etiology of fetal monstrosities continues to be poorly understood. Many of the congenital defects are inherited while others are due to the environment (nutrition, toxins, and infections). Changes usually do occur in the conceptus during the embryonic period (day 14 to 45 of gestation). Although uncommon in most dairy and beef cattle herds, congenital anomalies are found in all breeds of cows and propagated as a result of specific trait selection that inadvertently results in the propagation of the defect [50]. The most common inheritance pattern is a simple recessive trait. A large number of fetal monstrosities have been reported in buffalo species [17] but none has been traced to be of genetic origin. There are many teratogenic agents that are present in the environment. Each one can affect one or several species of animals. Some of them include tobacco, poison hemlock, lupine, locoweed, Sudan grass and even potatoes [51-53]. Viral infections like Blue tongue, Akabane virus, Border disease, Cache Valley virus and BVD can result in congenital defects in cattle [54-56] and many of these diseases also affect buffalo [26,57,58] hence their likely role in buffaloes cannot be ruled out. There is paucity of data on the antenatal diagnosis of fetal monstrosities [1]. Diagnosing the cause of a congenital defect after the birth of a fetus is also difficult and requires constant cooperation of animal owners, veterinarians, technicians, and pertinent diagnostic laboratories [59]. Therapeutic options for fetal monstrosities are oriented towards selected breeding if the origin of the defect can be traced. If a congenital defect can be diagnosed during pregnancy the termination of such a pregnancy is suggested [1].

2.1. Dropsical Conditions of the Fetal Membranes

The term dropsy means swelling of soft tissues due to excessive accumulation of fluid.

The dropsical conditions of the fetal membranes are hydroamnios, hydroallantois and edema of the allantois chorion. The conditions are usually present singly but rarely may be found together. Although dropsical conditions of fetal membranes are rarely encountered, hydroallantois is relatively common in cattle compared to other dropsical conditions, however, dropsical conditions are less frequent in the buffalo [17].

2.1.1. Hydroallantois (Hydrops allantois)

This condition is seen sporadically in buffaloes [60-67] and rarely in hybrids (cattle x bison) [68]. The condition is usually associated with a diseased uterus in which most of the caruncles in one horn are not functional and the rest of the placentomes are greatly enlarged and possibly diseased [69]. The condition may be observed in cows carrying twin fetuses. More recently it has been shown that hydropic conditions are common in cloned pregnancies [70-73]. The abnormality is probably caused due to structural or functional changes in the allantois chorion including its vessels, and transudation and collection of fluid resembling plasma. Fetuses may be slightly smaller and show some edema. Nutritional deficiencies have been described to cause the condition [74], however; the exact etiology continues to be poorly understood.

Antenatal diagnosis of the condition is dependent on the clinical signs. The signs of hydroallantois vary depending upon the degree of involvement and the stage of pregnancy. In mild cases where the amount of extra allantoic fluid accumulation is moderate, clinical signs are not appreciable during pregnancy, and increased fluid is only noticed at parturition when uterine inertia may also be present. In severe cases, the fluid accumulation increases rapidly over a period of 5 to 20 days and is recognizable clinically by bilateral distension of the uterus and abdomen (Fig. 9, Fig. 10) after mid gestation. As much as a 10-fold increase in allantoic fluid volume, up to 200 L [69,75,76], has been reported (normal volume of allantoic fluid near term (8-15 L) [77]. Placental dysfunction is evident by the occurrence of adventitious placentation characterized by a reduced number of placentomes (less than 75) and the development of a more primitive villous placentation in cattle. Dysfunction of fetal kidneys may be present [69,78]. Choriocarcinoma has been recorded to be a cause of repeated hydropsy in a dairy buffalo [78]. Affected animals have a bilateral distension and an apple shaped abdomen. They are distressed, anorectic and have no rumen activity (due to compression). Dehydration and constipation follow and eventually animals may become recumbent. During transrectal examination, the uterine wall is very tight and it is difficult to palpate the fetus. Ultrasonographic findings in cows are inconclusive as there is difficulty in observing the fetus and its annexes although larger sized placentomes are visible [70]. The depth of the uterus and the size of the calf may be the limiting factors for fetal ultrasonography in cattle [8]. Similar descriptions in buffaloes are lacking. When the condition is diagnosed early, parturition must be induced using prostaglandins and corticosteroids [39,63,79]. However, care must be taken to supplement sufficient fluid replacements to avoid death of the animal due to shock. Gradual drainage of the fluid by repeated trocharization is possible, with concurrent fluid therapy; however, the allantoic fluid readily re-accumulates [34]. The prognosis for future fertility is generally poor. Laparohysterotomy may be suggested in some cases that require immediate termination of pregnancy but, due care must be exercised to avoid sudden withdrawal of allantoic fluid in order to prevent shock. Cows in which parturition was induced because of a presumptive diagnosis of hydroallantois at our center, died during or immediately after induced parturition [1].

Figure 9. A buffalo with hydroallantois. The extensive enlargement of the abdomen is visible. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India).

Figure 10. A buffalo with hydroallantois. The extensive enlargement of the abdomen is visible. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India).

2.1.2 Hydroamnios (Hydrops amnii)

Hydroamnios which is a rare condition [34], is characterized by a gradual enlargement or filling of the amniotic cavity and is associated with a congenital defect of the fetus [69,80], with fetal anomalies such as impaired deglutition or renal dysgenesis or agenesis [34,80]. The condition is rare in the buffalo. The condition develops slowly over several days or months during the latter half of pregnancy, usually the last six weeks of pregnancy in cattle [81]. Antenatal diagnostic procedures for diagnosis of hydroamnion in cattle and buffalo are far from perfect and visual diagnosis is still the most frequently used procedure [1]. Looking from the rear, buffaloes (Fig. 11, Fig. 12) with hydroamnios have a pear shaped abdomen [34]. With the exception of the difficulties in observing the fetus and smaller placentomes in ultrasonographs, no precise ultrasonographic descriptions of the condition have been reported [70]. The antenatal diagnosis is thus dependent on the clinical signs. Pregnancy termination is suggested if the condition is diagnosed early. Often the condition is not recognized until parturition when a large quantity of syrupy, viscid amniotic fluid occasionally containing meconium is released. The fetus is usually small but dies shortly because of defects [82,83]. Sometimes, there may be uterine inertia and a resultant dystocia but this can be handled easily. The prognosis and future fertility of cows and buffaloes is good, however, if a genetic predisposition is found, it has been suggested that the dam and sire both be discarded from future breeding.

Figure 11. A buffalo with hydroamnios. The abdomen is distended and pear shape when viewed from the rear.

Figure 12. A buffalo with hydroamnios. The abdomen is distended.

2.2. Fetal Dropsical Conditions

Three fetal dropsical conditions are commonly discussed in cattle and buffalo. In these conditions there is an excess of body fluid, primarily within the fetal interstitial spaces. Nomenclature of the condition depends upon the location of the fluid: hydrocephalus-meninges of the brain; ascites-abdominal cavity and anasarca- generalized all over the body. In humans the conditions are collectively named as "hydrops fetalis" because more than one type may be existent at the same time [84].

2.2.1. Hydrocephalus

Hydrocephalus has been reported in many buffalo breeds [66,85-89]. Two types of hydrocephalus have been described: the external hydrocephalus- in which the fluid accumulates in the subarachnoid space exterior to the brain; and the internal hydrocephalus- in which fluid accumulates in the ventricles of the brain. The fetus dies at birth or soon after birth. The etiology of fetal hydrocephalus in humans is associated with intracranial hemorrhage [90], chromosomal abnormalities [91,92], and vitamin K deficiency [93]. In the bovine species an autosomal recessive gene is considered responsible for many hereditary causes [94-96], but infections and nutritional factors may also play a role [97], however, the exact etiology of the condition continues to be poorly understood both in animal and human subjects [90]. Antenatal diagnosis of the condition is important in human medicine because it can result in neurological disorders in newborns. Ultrasonography is routinely done to diagnose hydrocephalus in human patients. The ventricles within the head measure larger than normal. Amniocentesis is performed to evaluate chromosomal abnormalities. Fetal magnetic resonance imaging (MRI) can provide additional information about the soft tissues [98]. Since the routine evaluation of mid to late gestation pregnancies in buffalo is not common, the antenatal diagnosis of fetal hydrocephalus is not possible. In one report, two cows with a prolonged gestation were studied by transabdominal ultrasonography and hydrocephaly was detected in one fetus [99]. The condition is generally found at the time of parturition. Death of the fetus results due to pressure on vital centers of the brain. The frontal, temporal and parietal bones are usually involved which become deformed separated and thin. Diagnosis of the condition subsequent to birth of the fetus is easy. A high dome shaped forehead (Fig. 13) and downward slant of eyes is characteristic to hydrocephalus. No specific therapy is suggested during gestation. The role of pro-inflammatory cytokines (present in the cerebrospinal fluid) in the development of hydrocephalus has been recently shown [100] but the efficacy of anti-inflammatory therapy has not been investigated. When the enlargement is excessive, the passage of the fetus through the birth canal at parturition may be difficult and cuts on the head are suggested to reduce the size of the fetus [86,89,101] and a caesarean section may be required in difficult cases [85,86].

Figure 13. A buffalo fetus with hydrocephalus and prognathia delivered from an aged Murrah buffalo by traction.

2.2.2. Fetal Ascites

Fetal ascites is the accumulation of excess of fluid in the abdominal cavity of the fetus. It is known to occur in cases of brucellosis, mesotheliomas of the fetal abdomen or fetal death with sterile autolytic changes [69]. The condition has been reported in buffaloes [66,102-108]. Various etiologies defined recently for fetal ascites in humans are: genetic causes, fetal structural abnormality, congenital syphilis or other infections, fetal environment, placental defects, renal problems of the fetus, teratogens and idiopathic causes [109-111]. Similar causes may probably exist in the buffalo. Antenatal diagnosis of fetal ascites has not been described for cattle and buffalo. Diagnostic procedures described for horses mention ultrasonography [112] and those for humans include ultrasonography, Doppler studies, fetoscopy and amniocentesis [111]. Elective cesarean section is suggested for human patients with hydrops fetalis including fetal ascites [113] and for fetuses delivered normally surgical repair is recommended [114,115]. Similar approaches are not described for the buffalo. During parturition, the distended abdomen of the fetus (Fig. 14, Fig. 15) is wedged at the pelvis and results in dystocia in cattle [16] and buffaloes. Such fetuses seldom survive and hence an incision on the fetal abdominal wall is made to release the extra fluid. The fetus can then be easily removed in cattle and buffaloes.

Figure 14. A buffalo fetus with fetal ascites. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India).

Figure 15. A buffalo fetus with fetal ascites. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India).

2.2.3. Fetal anasarca

Anasarca means generalized edema all over the body (Fig. 16, Fig.17). The condition is rare in the buffalo [116-118]. Abortions of affected fetuses are common between 4 to 8 months of gestation in cattle. The condition has been described to affect Ayrshire cattle and is caused by a recessive autosomal gene. Most anasarcous fetuses are expelled dead. When the fetus poses difficulty in its delivery, cuts must be given over many places to release the fluid or fetotomy and/or forced extraction may be used to deliver the fetus. Rarely caesarean section may be indicated. Antenatal diagnostic techniques described for the diagnosis of hydrops fetalis including fetal anasarca in humans include ultrasonography [119] and magnetic resonance imaging [120]. Similar descriptions are not available for the buffalo and the therapy suggested is termination of pregnancy [39].

Figure 16. Anasarca in a buffalo fetus delivered by traction.

Figure 17. Anasarcous bubaline fetus. (Photo Courtesy Dr Gyan Singh, Assistant Professor, Teaching Veterinary Clinical Complex Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, India).

3. Ectopic Pregnancies

Although abdominal pregnancies have been described in human and animal species, tubal ectopic pregnancies appear to be restricted to primates. Other than anecdotal cases, this pathological condition does not occur in domestic or farm animals [121]. In primary (true) ectopic pregnancy, the feto-placental unit forms outside the uterus. This is seen in primates where the placenta is invasive and the uterus is simplex whereas such conditions are not possible in domestic animals. Although primary abdominal pregnancies have been reported in domestic species [122-125], no viable feto-placental units outside an intact uterus have been found during the latter half of pregnancy. A secondary extra uterine pregnancy is one which has a feto-placental unit in the uterus but is located outside the uterus.

Some mechanisms which distinguish women from domestic animals are:

1. In women, the presence of embryo is not required in the uterus for luteal progesterone secretion
2. The human embryo is capable of surviving in either the tubes or the uterus
3. The placenta is hemochorial and implantation is invasive.

All these characters are not found simultaneously in any domestic animal [126] and hence a primary ectopic pregnancy is usually not possible in most domestic animals including the buffalo. However, the accidental rupture of the uterus with resultant ectopic pregnancy has been recorded in a cow [127]. Clinical signs of distress, ultrasonography, peritoneoscopy and other techniques are commonly employed in humans for the diagnosis of ectopic pregnancies, but since no true ectopic pregnancy has been found to occur in the buffalo, their antenatal diagnoses are out of question. An emergency laparohysterotomy is routinely practiced in confirmed human ectopic pregnancies but such techniques are seldom required in the buffalo.