The placenta, or cleaning, is what connects the calf in the womb to the cow. At the calf end, the cleaning is connected through the calf’s naval, while at the other end the cleaning is connected to the wall of the womb through hundreds of cotyledons through which oxygen and nutrients are passed from the cow to the calf.

These cotyledons are like snap-on buttons on a shirt. Normally, they detach themselves from the womb between two and eight hours after calving and the cleaning pops out. When the cleaning doesn’t come out after 12 hours, it is considered to be a retained cleaning as some of the cotyledons did not detach.

There is a higher likelihood of retained cleanings in cows that have had hard calvings, twins, milk fever or a mineral deficiency.

A retained cleaning in itself tends not to cause a problem, but can lead to problems. A hanging cleaning, while unsightly, also leaves the cow open to infection. Because it is in contact with the outside world, it offers a bridge for bacteria that come in contact with it to enter the womb and cause infection there. The other major problem is that over time, the cleaning will naturally degrade. As it does so, it can become toxic, causing sickness and infections.

Retained cleanings are nearly always due to a lack of muscle power in the womb. After a hard calving or twins, the muscles around the womb can be exhausted and don’t have enough energy or power to snap off the cotyledons and push out the cleaning.

A mineral or vitamin deficiency can also reduce the muscle power of the womb – leading to slower calvings and then retained cleanings.

Other than selecting easy-calving sires and making sure the nutritional, mineral and vitamin status of the cow is up to standard, particularly around magnesium, copper, iodine, selenium and calcium, then there is not much more one can do.

Cure

Dealing with retained cleanings is difficult, as it affects cows differently. Some cows get sick a day or two after calving, while other cows can have a retained cleaning for over a week and remain healthy.

The temptation is always to pull the cleaning out, but this is not advised, especially not in the first five days after calving.

The risks with pulling out the cleaning are two-fold. Firstly, damage could be done when pulling the cleanings, as the wall of the womb, on which the cleaning is attached, is already weakened and harm may be done. Secondly, there is a high risk of the cleaning splitting, with the part of the cleaning left in the womb more likely to remain there, turn toxic and lead to further problems.

Some people cut the cleaning off just below the vulva, but this is not recommended either as this reduces the pull effect and does nothing to reduce the risk of bacteria entering the womb.

Sometimes, a light pull on the cleaning on day five is sufficient for all the cleaning to come out, especially if the cow exerts some internal force also. The majority of cows that have retained cleanings also have some degree of metritis or womb infections. The degree of metritis can vary, but in acute cases, there is a foul-smelling brown watery discharge from the uterus, a high temperature and the cow will be visibly sick and off her feed.

In such cases, the vet should be called and they are likely to put a Metricure or other antibiotic into the womb and maybe put the cow on a course of antibiotics too. A number of washouts, a couple of days apart, may be needed before the womb cleans. Some people continue to use iodine washouts, but the solution must be very weak, like weak tea, with not more than 20ml of Lugols iodine in every litre of water (2%).

Some vets prefer to just use lukewarm water with a pinch of salt as a washout to dilute the contents of the womb, and feed this into the womb using an adapted stomach tube or similar device, without exerting too much pressure on the womb.