After the 11 months duration of a mare’s pregnancy, every breeder hopes for safe delivery of a live foal and a healthy post-foaling mare.
To maximise the chances of this outcome, there are a number of routine procedures which should be undertaken during late pregnancy.
What should the check list prioritise on the daily routine monitoring of the mare in late pregnancy?
Routine paddock checks on each pregnant mare should include the following:
Monitor signs of health – e.g. mare alert, grazing, normal mobility, not separated from the group, etc. It is not normal for horses to separate from the main herd. Usually where this occurs in a mare that is within a few months of foaling, she is either sick or there is a likelihood that she is about to abort.Premature increase in udder size, waxing, or running milk. Where there is a sudden increase in the mare’s udder size or where she is ‘running milk’ a few months before the due date, then the likelihood is that there is an imminent abortion about to occur.Signs of discharge on the mare’s “bearing”. Where this occurs, the veterinary surgeon should be called in to check for suspected placentitis (infection in the placenta). The veterinary surgeon may scan the mare to confirm this and she may then be treated with a course of suitable antibiotics, to prevent an imminent abortion (culture of discharge determines the antibiotic treatment). Signs of colic.Abnormal/sudden oedema or fluid accumulation in the lower abdominal area. This may be caused by an increase in the fluid within the placenta (‘hydrops’) which can lead to further complications and foaling problems etc.Lameness – laminitis may become a problem during these stages. Also mares with ‘flat feet’ have a tendency to become sore or “footy” due to carrying the extra weight of the foetus.The routine checks on pregnant mares should be carried out at least on a daily basis with the frequency increasing as pregnancy advances into the later stages. What is the commonest cause of abortion in mares?
TwinsWhat foot care is recommended for the pregnant mare?
The extra weight of pregnancy places increasingly more pressure on the mare’s feet so constant attention to foot care and regular trimming of feet is essential. Sore feet will deter the mare from exercising at grass as her feet are too painful to exercise normally in the paddock. The result is oedema/stocking up or build-up of fluids in the limbs and lower abdomen during the latter stages of pregnancy. This problem requires veterinary treatment to enable the mare to move with ease, ensuring that she gets adequate exercise.How often should the pregnant mare be wormed?
Routine worming every two to three months of the entire group is recommended and more frequently in intensive systems where there are higher numbers of horses together. On a general basis, worm dosing is usually not advised in the last few months of pregnancy.The more intensive the systems are, i.e. the higher the numbers of horses on a farm, the greater the worm burdens are likely to be in the horses grazing on it, so good pasture management is very essential.Should the parasite treatments include lice/ectoparasitic treatments?
Lice treatment: It is important to check mares for the presence of lice. If there are lice present, all mares should be treated if they have already had direct contact with each other. If any animal in the group is not treated, it acts as a reservoir for the lice. Subsequently re-infection of the entire group may occur when the effect of the treatment dressing has ceased to act on the other horses. What vaccines are recommended for pregnant mares?
Viral Abortion: To prevent viral abortion, Equine Herpes Virus (EHV) vaccine, should be administered at five, seven and nine months stages of pregnancy. Rotovirus: Rotavirus vaccine can be given at eight, nine and 10 months. This prevents rotavirus diarrhoea in the newborn foal. Tetanus toxoid: If given in the last month of pregnancy, Tetanus Toxoid transfers immunity against tetanus to the newborn suckling foal. Therefore this foal will not require an anti-tetanus injection at birth. The navel in the newborn foal is equivalent to an open wound and an entry route for tetanus or other infections.Should the pregnant mare be rugged?
This is debatable. Generally where mares have access to good shelter, they should not need rugs. If a mare is susceptible to rain rash, rugging may help to prevent it.Disadvantages of rugging pregnant mares include the following: Rugs obscure the mare’s udder from viewing, on the routine daily checksPressure sores may develop from ill-fitting rugs. If mares have a lice problem which has not been detected, rugging will exacerbate it, as its thermal effect increases lice activity under the rug.On rare occasions, the back rug strap can become entangled in the tail and ligature it without the knowledge of the owner. This could result in loss of the tail.Newborn foals may become entangled in the rug straps.Should mares in late pregnancy be housed at night?
With the emerging pattern of extremes in our weather conditions, it is advisable to make provision for earlier housing of pregnant mares.Under normal circumstances this may not be necessary, as in general, horses are far healthier outdoors provided they have access to good shelter. To facilitate close monitoring, each pregnant mare should be kept in a paddock close to the barn as she gets closer to her foaling date. Does the mare require more feed in late pregnancy?
Yes. Up to 60% of the foal’s growth occurs in the final third of pregnancy, which usually coincides with late winter/early spring when grass is scarce. So to maximise the full development of the foal, it is vital to supplement the mare’s diet with stud nuts or alternatives of choice. However, a balanced diet should ensure that she is not over-fat at foaling.