Caslicks and vulval repairs – why would you sew up a mare’s lady parts!?

The idea of sewing up a mare’s private parts sounds like something from the deepest, darkest recesses of a horror film franchise. But believe it or not the practice actually has a very useful purpose – and is routinely practiced on many mares.

There are two reasons that a mare’s vulva may need stitching – for repair and for caslicks.

Vulval Tear Repairs

The repair of the mare’s vulva after foaling is probably the more common practice that people have heard of. Sometimes when a mare is foaling her vulva tears due to stretching.

This can occur in maiden mares who have never ‘stretched’ before, mares who deliver disproportionately large foals, and when foaling attendants interfere and pull the foal out before the mare’s body is ready to deliver it. They can also occur if the foal is not correctly proportioned.

Whatever reason they occur, the tears can be anywhere from very small (sometimes small enough to heal on their own) and other times they are much larger. These tears (called perineal tears – the perineum is the area around the mare’s anus and vulva) will need to be repaired by a vet. These tears can be very severe – and in some cases can tear all the way up to the anus.

If this occurs a vet will need to be called to surgically repair the tear in the mare’s vulva. These tears are generally repaired by the vet stitching the torn section of the vulva back together under anaesthetic. Often dissolvable stitches are used so they don’t need to be removed.

These tears can predispose mares towards tearing again at foaling because the area is already weak, however the large majority of mares go on to foal without any further issues.

  • Facebook
  • Twitter
  • Google+
  • Pinterest

Vulva torn during foaling


Caslicks are a little less well known and can be a little more confusing for people. So we’ll start by looking at why we do them, then at how.

The reproductive tract of a mare needs to be sterile – it’s not supposed to have any external bacteria in it.

The anatomy of a mare is slightly unfortunate in that the anus and rectum is located directly above the vulva and reproductive tract. In many mares this isn’t a problem because the lips of the vulva seal tightly to create a barrier to the reproductive tract that keeps faecal matter and other bacteria out.

In some mares the integrity of this seal is compromised. This can happen for a number of reasons. Sometimes multiparous mares (mares who have had numerous foals) can end up losing some of the retraction and elasticity in their vulva due to birthing a large number of foals. Others have unfortunate conformation which means that the anus is sunken and creates a ‘shelf’ where the faeces can sit and then fall into the vulva and enter the reproductive tract.

Bad vulval conformation is something that can develop or something that can occur naturally – the mare is just ‘born that way’. Some mares who are born with bad vulval conformation have a sloping vulva that angles back towards the anus – this causes a similar problem to the sunken ‘shelf’ conformation.

Whatever the reason, if a mare has bad vulval conformation then the chance of bacteria entering her reproductive tract is higher and this can lead to difficulty getting in foal and difficulty staying in foal. Bad vulval conformation can lead to infections in the placentitis and subsequent abortion of the fetus.

To prevent this from happening a Caslick is carried out on the mare once she has had her final positive scan.

The mare is given an anaesthetic to numb the area and then the vet takes off a very thin layer of skin from each side of the vulva. This exposes the ends of the blood vessels. The vet then sutures these two sides together and, as they heal, the blood vessels from the two sides fuse together as the heal and creating an artificial ‘seal’ to prevent bacteria entering the reproductive tract through the vulva.

This procedure is very common and minimally uncomfortable or invasive for the mare. It is generally done in a crush and is a regular part of the routine on many studs.

  • Facebook
  • Twitter
  • Google+
  • Pinterest

Mare ‘caslicked’ – what it looks like after healing. You can see the creation of the artificial seal where the skin has ‘sealed’ together

If a mare has been ‘caslicked’ it is important that the caslick is opened before foaling. Once the mare begins to show signs of foaling (udder development is the main one used as a gauge) then the caslick is opened to ensure it is open when she foals.

To check whether your mare is caslicked simply insert a finger gently into the vulva, pointing up towards her back. Normally the conformation of the vulva means that there should only be a small amount of skin at the top of the vulva that your finger sits behind – around half a fingertip long. If the mare is caslicked you will find that as much as the whole length of your finger will fit behind the skin – depending on the length of the caslick.

If you are not experienced opening caslicks I would highly recommend getting a vet to open the mare. It can be difficult and uncomfortable for the mare and can put you at risk of getting kicked or otherwise injured.

In the event that a mare is foaling and her caslick has not been opened you may have to do an emergency opening. A scalpel is the easiest tool to use, and the opening is completed by cutting gently upwards until the vulva is opened to its natural length. In most cases you can also see visually where the caslick ends based on the colour of the skin and scar tissue.

If the mare is foaling through a caslick it is important to be careful not to cut the foal’s nose as it presents at the vulva. Ideally you would get someone to push this back in – it is also easier to open a caslick when the mare is standing, rather than when she is lying down. For this reason I ALWAYS recommend that people keep a scalpel in the foaling kit (it’s also crucial for a red bag foaling too!).

  • Facebook
  • Twitter
  • Google+
  • Pinterest

Caslick (the above mare) after being opened before foaling.

Caslicks have their place in foaling, but it’s important to know what to look for and when a caslick needs to be completed. A mare foaling through her caslick can end up with horrific tears and injuries as she pushed the foal through the stitched up vulva, so if you have purchased a new mare or are foaling a mare from someone else it always pays to check if she has a caslick. If you’re not sure – better to be safe than sorry – get a vet to check her out!

Hopefully that clears up a little bit of the mystery behind why we stitch mares up – if you have any questions please feel free to head over to our Facebook Support Group at

We have some other exciting things on the go at the moment – the Intro to Foaling Online Course has been RELAUNCHED and LIFETIME ACCESS can be purchased (at three different pricepoints starting from only $149) at

Our FoalEd Online Shop is also open at, where you can purchase loads of resources priced from only $6.95 so make sure you check it out!

As always, happy foaling!

The Horse Midwife

P.S. As always please feel free to check out our Website ( or Facebook Support Group (, or download our free Foaling Roadmap at


Pin It on Pinterest