Introduction
Dystocia is defined as a difficult birth due to long, unassisted parturition or prolonged delivery requiring assistance [1,2]. Dystocia occurs often due to disproportion in the feto-pelvic ratio, uterine inertia, inability of the cervix to dilate fully, wrong presentation, postural/positional, and disease/congenital defects in lambs. In Sheep, the effect of dystocia could result in lambs that are born dead, or lambs with injury, or in cases where the lambs survived the parturition, they may be weaklings. Causes of dystocia can be maternal or fetal in origin and its incidence is higher in multiple births than single birth, primipara than multipara ewes, and in male than female lambs. Cases of dystocia should be attended to without any delay as it is regarded as an obstetrical emergency. From its signs, the obstetrician can identify the exact point at which normal birth ceases and dystocia occurs.
Irrespective of the etiology of dystocia, the consequences of prolonged parturition and dystocia on the fetus (es) are an increased risk of asphyxia and circulatory compromise leading to central nervous system lesions and edema. In one study, up to 33 % of newborns experienced severe asphyxia with a risk 15.6 times higher for twin-born lambs compared to singles [3]. Dystocia-associated impacts on the ewe may be attributable to trauma, hemorrhage, and septicemia [4]. Ewes with dystocia at their first lambing may have a higher risk of dystocia at subsequent lambings [5].
The risk of dystocia is elevated when a primer ewe is carrying twins; especially if one or both fetuses have abnormal postural and positional orientations. The causes of dystocia could be as a result of fetal, maternal, and management causes.
Fetal causes
Size and presentation: Large fetal size, abnormal presentations (e.g., breech or transverse), and multiple births can cause dystocia. In primer ewes, the smaller pelvic canal increases the risk of these issues.
Congenital abnormalities: Conditions such as hydrocephalus (excessive cerebrospinal fluid in the brain), fetal mummification, or skeletal deformities can complicate delivery. Hydrocephalus, in particular, leads to an enlarged fetal head, which can obstruct the birth canal.
Maternal causes
Pelvic size and shape: A primer ewe may have a narrower pelvic canal compared to multiparous ewes, making it more difficult for the fetus to pass through.
Uterine contractions: Inadequate or erratic uterine contractions can impede the progress of labor.
Management practices
Nutrition: Poor nutritional status can affect fetal growth and uterine function. Both under nutrition and over nutrition can lead to complications.
Breeding management: Selection of sires and breeding timing can impact the likelihood of dystocia. For example, breeding ewes with larger rams may increase the risk of fetal size-related dystocia.
This case report describes the clinical management of dystocia due to a postural defect in a 1-year-old primiparous ewe.
Case Presentation
Case history and clinical examination
A pregnant 1-year-old Uda ewe weighing 26.5 kg was presented to the Large Animal Clinic Unit of the Veterinary Teaching Hospital, University with the chief complaint of persistent straining during the second stage of parturition. History revealed that the ewe is a primer had been observed to be straining 2 days before presentation.
Physical Examination
On physical examination, the forelimb of one of the fetuses is seen hanging outside the vulva with the right limb flexed and also with a lateral deviation of the head. The ewe was also observed to be straining heavily as evidenced by tachycardia. Examination of the fetus in-utero showed that the fetus was already dead as no pedal reflex was observed. The dystocia was therefore confirmed to be caused due to fetal mal-posture characterized by the presentation of the right limb flexed backward and with lateral deviation of the head. These may have caused a fetomaternal disproportion (Fig. 1 and Table 1).
Figure 1.
Patient on the day of presentation with hanging fetal limb.
Table 1.
Patient vital parameters on the day of presentation.
| Vital parameters | Values |
|---|---|
| Temperature (degree Celsius) | 38.6ºC |
| Pulse rate (beats/minute) | 120 |
| Respiratory rate (cycles/minute) | 30 |
Management for this case was to remove the fetus by manual traction after generous lubrication of the birth canal and mutation of the fetus. This allowed for a successful delivery. The first fetus delivered was small with an elongated left forelimb seen in Figure 2. The dam was thereafter administered with Amoxicillin L.A® at 1 ml/10 kg IM, inj., Calcium borogluconate 10 mls IV, and oxytocin 10 IU IV and there was an uneventful post partum.
Figure 2.
First female fetus presenting with the elongated left limb.
The second fetus was observed to have hydrocephalus on delivery characterized with an enlarged and elongated head with exophthalmia as seen in Figure 3a and b.
Figure 3.
a. Male fetus with hydrocephalus and 3b. Exolpthalmia.
Discussion
The dystocia observed in this particular ewe was of fetal origin and was due to malposture as the first lamb presented the left forelimb with the right limb flexed and lateral deviation of the head and the other with hydrocephalus and exophthalmia causing misproportion of the fetal size to the birth canal which is a common cause of dystocia [6,7]. The flexed right limb and lateral deviation of the head of the first fetus obstructed the normal presentation for delivery and the malproportion of the fetal size of the second fetus and birth canal caused a difficult birth which resulted in dystocia.
One most common congenital disorder in lambs which may also be caused by nutritional deficiencies, especially copper is hydrocephalus [8]. Hydrocephalic fetuses in sheep is often a genetic problem or caused by environmental factors but could also be infectious is observed when there’s an imbalance between how much cerebrospinal fluid is produced and absorbed into the blood stream which is characterized by an enlarged head [9]. Therefore, with continued production and decreased absorption or obstruction, the fluid keeps accumulating making the head to swell up, this further causes increased intra cranial pressure and pushing or bulging of organs like the eyes (exophthalmia) [10].
The dystocia was relieved by traction, which involves supplementing the maternal expulsive force with a pulling force. The death of the lambs as recorded in this case may be as a result of delayed timing of assisting in the delivery., This is in consonant with the report that timing is of necessity when handling a case of dystocia, as a delay in intervention will lead to the death of the lambs and even possibly a dead ewe [11]. The client had reported that the ewe had been straining for over 48 hours, as they were attempting to aid delivery themselves.
Furthermore, ewes/rams observed with any genetic problem should be carefully observed and prevented from breeding as it could further cause complications during pregnancy, delivery, and during nursing. Antibiotic medication was given to the ewe as it is recommended to give antibiotic medication to female animals that had undergone any form of assistance to aid delivery; it is believed that this will help to reduce the risk of infection of the dam.
