Monday, 1 April 2019

Udderly troublesome: Mastitis in sheep

Kate Bamford is researching the role of chronic mastitis in sheep at the University of Warwick.
Her PhD, funded by AHDB Beef & Lamb, will complete in Autumn 2020. Here she writes a guest blog about how you can prevent and treat mastitis in your flock.

The sun is shining, the daffodils are out and the lambs are filling up the field. What could be more troublesome than finding a hungry and sad lamb? Mastitis in suckler sheep is often seen in the first two weeks of lactation, and then just before or after weaning. However, it’s possible at any time, so it’s important to be able to spot the signs early and make sure no lambs are left hungry. 

Spotting acute mastitis

Mastitis is defined as ‘inflammation of the udder’ and is usually caused by a bacterial infection. You can usually spot a ewe with mastitis when they have hungry lambs, are waddling to avoid touching their udder with their back legs, have gone off their food or are away from the rest of the flock.

The udder can feel hot and swollen and might be red in colour. Often acute mastitis will only affect one side of the udder and the ewe will have no milk from that side. If there is some milk, it may look watery, bloody or clotted. When you milk out, make sure it is into a container and not onto the floor, as this may spread the mastitis bacteria to other ewes.

Fast treatment

The earlier you catch acute mastitis the more likely the ewe is to fully recover. Even with fast treatment, there probably won’t be enough good quality milk for her lambs, so you may need to consider fostering or bringing them up as pet lambs.

As mastitis is a bacterial infection, you need to ask your vet which antibiotic they would recommend. It is also a good idea to give a painkiller and anti-inflammatory.

Mastitis is a painful disease and a ewe in pain will take longer to get back on her food. The anti-inflammatory will also begin to act on the swollen udder and help remove toxins caused by the infection.


Once lambing has started there are a few things you can do to reduce mastitis. Maintaining a high standard of hygiene in the lambing barn will keep the levels of bacteria down. Top up with fresh straw and remove wet soiled bedding where possible. When checking milk use a container and wash your hands between different sheep. Keep a bottle of antibacterial gel in your lambing shed if hand washing facilities aren’t available.

Lambs are dependent on their mother’s milk for the first 3 – 6 weeks. Lactating ewes need more energy than pregnant ewes to keep up the high milk yield and quality without compromising their own body condition. Underfed ewes in lactation triples the risk of mastitis.

Older and younger ewes are more likely to get mastitis. 

When a ewe is lambing for the first time, it will also be the first time their udder has developed and so it is softer and more prone to bites and lesions. These increase the risk of mastitis. Make sure these ewes get sufficient feed to enable their development and consider keeping them separate from the rest of the flock. This will enable you to keep an eye on them, avoid bullying, and minimise exposure to mastitis. Leaving a single lamb on ewe lambs will also improve their chances of not developing mastitis.

Other prevention strategies can be used throughout the year before tupping and lambing to keep your flock at a reduced risk of mastitis. These include managing chronic mastitis in your flock and culling ewes with poor udder conformation.

Chronic mastitis

Ewes with chronic mastitis will have a lumpy udder. Sometimes only a small lump can be felt and sometimes there may be a collection of lumps in the udder.

These are abscesses formed by bacteria and they can grow, disappear and reappear in the same sheep.

We know that the presence of these lumps is strongly associated with cases of acute mastitis during lactation. Where there are more lumps in a flock there is also more acute mastitis and so regular inspection and culling of ewes with lumps may help reduce both cases of acute and chronic mastitis. 

For more information read the BRP + document Understanding mastitis in sheep