Yomismo

* Home
* Library
* Email
* Citation
* Print
* Log-out
-------------------------------------------------
Principio del formulario
 
Final del formulario
* Available in:
* English (only)
In:  Bubaline Theriogenology, Purohit G.N. and Borghese A. (Eds.). International Veterinary Information Service, Ithaca NY (www.ivis.org), Last updated: 10-Jan-2013;A5715.0113
Maternal Dystocia and Uterine Torsion in Buffaloes
G. N. Purohit
Department of Veterinary Gynecology and Obstetrics, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner Rajasthan India.
Cattle and buffalo are considered the species in which the incidence of dystocia appears to be highest [1]. Parturition appears to be easier in theriver buffalo because of a capacious pelvis, a larger area of ileum and the free and easily separable fifth sacral vertebra [2]. Compared to cows, buffaloes have a less conspicuous shorter and narrower cervix, smaller and less tight vagina and elongated and wide apart vulvar lips (Fig. 1) [3]. In spite of a longer gestation period in buffaloes (305 to 320 days for the river and 320 to 340 days forthe swamp buffalo [4]), lesser time is required for completion of first and second stages of labor [2,5,6] (70 and 20 minutes in river buffalo) and there is a preponderance for parturition during night hours [7].
The incidence of dystocia is considered to be higher in river than in swamp buffalo (in which it has not been described) [1] and also in primipara than in pleuripara [4], however, a fewstudies consider higher incidence of dystocia in pleuriparous buffaloes [8]. In a recent analysis, significantly higher proportion of dystocia affected buffaloes were in the first and second parities compared to all other parities [9].

Figure 1. The vulvar lips of a buffalo. To view click on figure
Causes of Dystocia in Buffaloes
The causes of dystocia are generally classified into thematernal and fetal causes. Buffaloes are known to have greater incidence of maternal dystocia [1,10,11], however, in several other studies; a higher incidence of fetal dystocia was recorded [8,12,13]. In the authors’ experience buffalo generally have fewer problems with the dilation of the birth canal compared to cattle and there is a greater incidence of uterine torsion in buffaloes [9].
MaternalCauses of Dystocia
The maternal causes of dystocia are considered to be arising either because of the constriction/obstruction of the birth canal or due to a deficiency of the maternal expulsive force [1,14].
1. Constriction/Obstruction of the Birth Canal
The constriction/obstruction of the birth canal can result in maternal dystocia and can be due to pelvic abnormalities, vulvar or vaginalstenosis, neoplasm of the vagina and vulva, vaginal cystocoele, incomplete cervical dilation, uterine torsion and ventral displacement of the uterus. An uncommon cause of constriction of birth canal is carcinoma of the urinary bladder [15,16] with metastasis in the cervix.
1.1. Pelvic Abnormalities
Pelvic abnormalities of the mother that can result in dystocia include small size of the pelvis [9],pelvic deformities or exostoses, osteomalacia and hypoplasia of the vagina and vulva [2]. Breeding of heifers at too young an age, breeding of poorly grown heifers, or breeding of heifers and cows that had pelvic fractures, can result in a smaller pelvis of the mother culminating in dystocia at parturition. Breeding of small sized breeds of buffaloes with breeds of larger size can result infetuses of bigger size getting stuck in the small sized pelvis of the mother, however; this has not been documented for buffaloes.
In buffaloes, the symphysis pubis is not fused completely as it is in cows [17], however, a narrow pelvis is a known cause of dystocia in the buffalo [18]. The incidence of narrow pelvis has been recorded to vary between 2.67% [9] and 7.79% [8]. The incidence of pelvic...