Flock Health Planning

Judith Lee, BVMS, MRCVS, (Graylen Flock)

As we all know, proper preparation prevents poor performance and that in a nutshell is the aim of a flock health plan.  Investing in time with your vet to discuss preventative health care and your flock’s performance will be money well spent but you can make a really useful start yourself.

There are several new online tools to help you. AHDB beef and lamb have developed a flock management calendar https://www.flockcalendar.com/ to simplify the process

The easiest way is to start with a calendar and plan your year. Put in your intended lambing date and then when you need to put the rams in. That gives you a date to wean the lambs. It also allows you to plan introducing the teaser tup, sponging, implants etc. if you are using them to tighten your lambing up.

Vaccinations: add the date you need to vaccinate your sheep:

Clostridial vaccines (e.g Heptavac P plus or Covexin): the lambs need 2 doses 4-6 weeks apart from 3 weeks of age and the ewes will need a booster 4-6 weeks pre lambing. Don’t forget that last year’s lambs and the rams need boosters too.

Abortion vaccines: these have to be given at least 4 weeks pre tupping and older ewes may need a booster after 3-4 years

Orf vaccine can be given to ewes 7-8 weeks pre lambing and then to lambs at turnout. This is a live vaccine so shouldn’t be used in flocks that are not infected and should be used very carefully.

You may also wish to use vaccination to prevent infectious lameness but caution should be used in sheep that have previously been treated with a wormer containing moxidectin 1%

In the past few years, we have seen infection with ‘exotic’ diseases like Bluetongue and Schmallenberg affecting the national flock and you should keep an eye on the farming press for alerts about these diseases. Vaccines should again become available here if there is a perceived threat.

Parasite prevention

It is really important to build into your plan a strategy for combating the major parasites that might affect your flock. Which treatments you use and when will vary from year to year as the weather has a significant effect on the level of challenge. AHDB have produced some really good booklets about controlling internal and external parasites. These are available on their website in the ‘Better Returns’ section.

Gutworms: controlling infection with gut worms requires a combination of grazing strategies and worming treatments. It is important to get a balance between treating lambs so they perform well and not encouraging the development of resistance on your farm. Of the gutworms only nematodiarus can cause significant disease before eggs are found in the faeces. It is important to follow the forecast for this worm (available on the SCOPS website) and treat your lambs with a white wormer if they are at a susceptible age when the peak is forecast. Rotate the worming groups you use frequently and only worm when you need to. Make sure you use wormers at the correct dose and that you have accurate weights for your sheep.  Generally speaking, adult sheep do not need regular worming apart from rams at tupping time and ewes with multiple lambs at lambing time.

Coccidiosis and Crytposporidia, these are protozoan parasites that can cause devastating scour in young lambs. Infection builds up on pastures and in buildings if they are used year on year. Discuss control of these diseases with your vet.

Fluke: the challenge from fluke varies from area to area, farm to farm and year to year. Increasingly, we are seeing resistance to the only product that treats immature fluke so grazing management is becoming more and more important. The NADIS website gives regional forecasts but each farm is different. Try to get some feedback from your abattoir about the level of fluke infection on your farm and discuss the options for diagnosis and treatment with your vet.

External parasites: controlling flies is vitally important in warmer weather. Fly strike is a distressing and potentially fatal condition and it can develop rapidly. 2 types of fly products are available: one group (the pyrethroids) kill the larval stages of flies and can be used to treat and prevent fly strike; the other group (IGRs) prevent larvae developing to the biting stage so will prevent but not treat fly strike. It is important to know what you are trying to do when you select your product. There is already some resistance to the pyrethroids so it is again important not to use this group all the time.

Scab and Lice: both these parasites can cause extreme irritation and spread easily from sheep to sheep.  OP dips will treat both but if dipping is not possible you need to use different products depending on which parasite your flock has (if you are really unlucky, they may have both) at this point you really need your vet’s help to make an accurate diagnosis.


As you will be aware resistance to antibiotics has meant that we need to use these carefully. Take some time to discuss which antibiotics you use with your vet and what you use them for. New evidence may change which antibiotics your vet recommends as time goes on. Treat only when necessary and at the correct dose.


The main threats to your flock come from other sheep!  Bought- in sheep can bring worms, fluke, anthelminthic resistance, scab, lice and infectious lameness as well as a host of other diseases. It is important that you are careful about buying in sheep and that you have a quarantine protocol in place to tackle all these challenges.

This is only a starting point, your flock health plan may cover lots of other issues on your farm but taking the time to plan and prepare can only improve performance!