Dystocia (Birth Problems) in Friesian Mares
THE PREVALENCE, CAUSE AND OUTCOME OF DYSTOCIA (birth problems) IN THE FRIESIAN MARE (A Fenway Foundation document)
To study the prevalence, cause and outcome of birth problems (dystocia) in the Friesian mare, data from 66 referred dystocia cases in the period of 2001-2006 was retrieved from hospital files and questionnaires by telephone. The race distribution for caesarean section was as follows:
2 Shetland ponies.
1 Shetland pony.
For assisted vaginal delivery:
The average race distribution of our hospital population is:
1% Shetland ponies
(11% others). 11/56(20%)
Friesian dystocias were due to transverse intra-uterine positioning and 22/56(39%) due to ankylosis of the head and neck or the limbs. Former studies of dystocia cases in mixed hospital populations mention a prevalence of transverse presentation of 14/141(10%)1, 12/166(7%)2, 9/96(9%)3 and in a predominantly draft horse population 98/601(16%)6.
The prevalence of dystocia due to ankylosis is reported as 10/150(7%)1 and 12/166(7%)2. 41/45(91%) Friesian mares that underwent caesarean section survived to time of hospital discharge. Similar survival rates are mentioned in literature: 89%2, 88%3. 19/45(42%) Friesian caesarean sections delivered a live foal, 5 of which had to be euthanised because of severe ankylosis. Mean dystocia duration for live foals was 165±73 minutes and 490±504 minutes for dead foals. Reported foal survival rates in literature are 23/77 (30%)4 and 6/19 (32%)5. 23/45
Friesian mares re-entered breeding in which mean duration of caesarean section to novel gestation was 9.2 months ± 8.4 (n=21). All mares that re-entered breeding produced a live foal (100%). Post-caesarean foaling rate in literature: 50%5 and overall post dystocia live foaling rate is reported as 67%2. In conclusion the results of this study indicate that the prevalence of dystocia due to transverse presentation and ankylosis is higher in the Friesian horse compared to other breeds, often necessitating caesarean section. Mare and foal survival after caesarean section is comparable to what is reported in literature. Post caesarean section fertility and chances for a live foal are excellent.
1. Frazer, G.S., Perkins, N.R., Blanchard, T.L., Orsini, J. and Threlfall, W.R. (1997) Prevalence of fetal maldispositions in equine referral hospital dystocias. Equine Vet. J. 29(2) 111- 116
2. Byron, C.R., Embertson, R.M., Bernard, W.V., Hance, S.R., Bramlage, L.R. and Hopper, S.A. (2003) Dystocia in a referral hospital setting: approach and results. Equine Vet. J. 35(1) 82- 85
3. Freeman, D.E., Hungerford, L.L., Schaeffer, D., Lock, T.F., Sertich, P.L., Baker, G.J., Vaala, W.E. and Johnston, J.K. (1999) Equine Vet. J. 31(3) 203-207
4. Vandeplassche, M. (1980) Obstetrician’s view of the physiology of equine parturition and dystocia. Equine Vet. J. 12(2) 45-49
5. Juzwiak, J.S., Slone, D.E., Santschi, E.M. and Moll, H.D. (1990) Cesarean section in 19 mares. Results and postoperative fertility. 19 (1) 50-52
6. Vandeplassche, M. (1987) The pathogenesis of dystocia and fetal malformation in the horse. J. Reprod. Fert. Suppl. 35: 547-552