What is Caslicks operation?
This procedure was named after a French veterinary surgeon in the 1930s, Dr Caslick, who identified the importance of the preconditions in relation to genital infection in thoroughbred mares. It is a minor veterinary surgical procedure carried out under local anaesthetic by the treating veterinary surgeon, where part of the mare’s vulva is stitched to a specific level to prevent intake of air bacteria resulting in contamination/infection getting into the reproductive tract. This results in infertility in the mare.The procedure is also carried out on some fillies.Approximately 30% of mares have had Caslick’s operation. How does the ‘dipped’ conformation lead to introduction of infection?
A mare or filly with this conformation is more likely to suck in air which is accompanied by bacteria and an internal or uterine infection.Why does a treating veterinary surgeon decide to do Caslicks on a mare?
The main deciding factor here is poor or faulty conformation of the mare’s vulva, i.e. ‘dipped in’ conformation.In the normal mare, the vulva provides the first effective barrier or seal to protect the mare’s uterus from ascending infection. Where this seal is less effective or ineffective, contamination of the reproductive tract occurs. With this type of conformation, the mare will take in air and bacteria resulting in infection. During pregnancy it could also result in embryonic death and in late pregnancy can result in placentitis and lead to abortion. Where the vulval malconformation is severe it can lead to pooling of the urine or urovagina.The more severe types of mal conformation can result in faecal contamination as there is a type of shelf formed on to which the faeces collect. As mares get older and have more foals, they are more likely to get more dipped in conformation and require stitching. What is the treatment of uterine infection in these cases?
Treatment is directed at correcting the cause of the intake of air as well as concurrently treating the resulting endometritis or uterine infection.Treatment of uterine infection is by douches and ‘stitching or caslicks operation. Failure to stitch this type of mare could result in a permanent uterine infection as the cause/taking in air has not been removed. How is the correction procedure carried out?
The surgical procedure rectifies this problem by removal of a small elongated section of skin from either side of the vulva and stitching it together, resulting in permanent healing and fusion of the two sides of skin. The sutures may be removed after 12 days.Does the mare require sedation for this procedure?
Not usually unless she is a particularly nervous or fractious mare. The mare is usually put into a stocks and local anaesthetic is infiltrated into the area for stitching.Are antibiotics used after stitching the mare?
Generally antibiotics are not required as infection developing on the wound post stitching would be rare. If Caslicks operation was carried out on these mares without following up with douches, could they ‘self cure’ of infection?
Yes, in many cases stitching alone, without uterine douches, can initiate a type of ‘self cure’ as the mare comes ‘in season’.During the heat period, the mare produces oestrogens (hormones) which are bacteriostatic (bacterial control) and which may clear the infection in the uterus through its own control through this hormone-based control system. Are some mares stitched while pregnant?
Yes, stitching or Caslicks is carried out in some cases to maintain a pregnancy. In these cases the veterinary surgeon, while scanning the mare, may note the presence of poor vulval conformation and he/she may advise stitching to maintain the pregnancy. This prevents the pregnant mare from taking in air, infection, resulting in placentitis (infection in the placenta) and early embryonic death/loss of the pregnancy. How soon after foaling is a mare re-stitched?
Usually as soon as possible but in many cases there may be bruising etc present in the area. In these cases a temporary repair should be used in order to minimise the chances of intake of infection.It may require a few days healing time before carrying out the full caslicks procedure.Does a mare have to be opened for covering?
Yes but partial opening of the stitched area may be sufficient. To ensure that this is done before covering the mare, it is important to inform the stud man that she has been stitched.A mare should not be covered while there is suture material remaining in place post-caslicks as this could cause injury to the stallion.Is a mare that is stitched considered to have an unsoundness?
No, but it would be mentioned on a veterinary cert. This should not detract from her breeding soundness unless in the case of an extreme mal - conformation problem.At what stage pre-foaling, should the mare be opened (Caslick’s operation)?
At approximately two weeks before foaling when the mare begins to “spring” or “bag up “ before foaling. This may vary slightly depending on the mare’s previous foaling history. The decision is on a case by case basis, depending on factors such as the presence of springing flagging, date due, previous foaling history of the mare, etc. Failure to open a mare before foaling may result in rupture of the vagina caused by the foal’s foot during delivery. In this case the foal’s feet may cause unnecessary tearing/rupture of the vaginal roof, resulting in a recto – vaginal fistula and possible infertility for the remainder of her breeding career. What is the likely outcome where a mare is opened early before foaling?
It is not advisable to open a mare too early as this may result in aspiration of air, infection and placentitis, abortion, or loss of a premature foal.When deciding when to open a mare, it is not advisable to adhere to using just the foaling date as some mares may normally carry a month over due date. In these cases if the due date was used, it would in fact be six weeks before her due date. The result here would be intake of air resulting in infection, placentitis and abortion/premature foaling.