On this page we cover some relevant health topics that might be useful. This is never an exhaustive list and we’re not giving advice – just trying to help you find out what constitutes best practice in some areas to keep your flock healthy and productive.
Topics covered on this page are as follows. Please scroll down to find each section:
- Buying in Stock and Worming
- Clostridial Diseases and Pasteurella
- Foot trimming, scald and foot problems
- Johne’s Disease
- Enzooitic Abortion of Ewes (EAE)
- Vaccine and drug transportation
We recommend all sheep keepers to educate themselves as to the main disease or welfare threats that can affect their flock throughout the year. Many of these topics are covered in flock calendars and a good reference book can always be helpful. And of course, do consult your vet as required.
AHDB Beef & Lamb have a large video library available on YouTube. These cover a wide variety of topics, including health matters and there is a search facility to find topics you are interested in. Here’s a link to the site.
Buying in stock and Worming –
When you buy in stock, be it your first sheep; more sheep; a new ram; then always make sure to follow a quarantine wormer protocol to avoid brining resistant worms onto your holding. Ask your vet for their latest advice on this. This Booklet for example, gives you advice as provided by XL Vets (as at January 2020), as well as general worming advice for your flock.
Worming best practice is an evolving subject, so to help you manage your flock do keep up to date with the latest thinking. Here’s a link to the AHDB YouTube videos on worming.
Clostridial diseases and Pasteurella –
Both Clostridial diseases (a family of diseases that can affect young lambs, usually fatally) and Pasteurella (which can affect both lambs and older sheep) can cause lamb losses. Luckily both these disease threats can be vaccinated against.
For Clostridial diseases:
- Breeding ewes require a primary course of two injections of an appropriate clostridial vaccine given four to six weeks apart followed by an annual booster four to six weeks before lambing (no longer than twelve months apart).
- Immunity will be transferred to the lamb providing they have had adequate colostrum (lambs should receive 10% of their bodyweight in colostrum within 24 hours and half of this amount within four to eight hours).
- Passive immunity runs out after a few weeks. Therefore, lambs should be vaccinated from about three weeks of age and a second dose should be given four to six weeks later.
- Lambs should be vaccinated with an appropriate Pasteurella vaccine from three weeks of age with a second dose given four to six weeks later.
- Lambs that received two doses in the spring may require a booster where the risk is high in the late summer/early autumn period. Speak to your vet or animal health adviser.
- Pasteurella can sometimes affect shearlings or adult sheep, so for complete safety vaccinate your whole flock.
Vaccines can be bought separately for Clostridial diseases (each vaccine may do a different number of the individual diseases) and Pasteurella, although many drug companies also sell combined vaccines that cover both at the same time. Buying a combined vaccine has the advantage of allowing all older sheep to be vaccinated against Pasteurella at the same time as giving the Clostridial vaccine and your rams and other younger stock can be included and protected with the same vaccine. Ask your vet or local agricultural supply merchant what they recommend.
This article from Farmers Weekly available on the web gives more information on the individual Clostridial diseases.
Foot trimming, scald, foot problems and foot-rot –
This whole area should probably be a Mastermind special subject for somebody who could cover all the different guidance that has been issued over the years as to best practice!
For trimming, “once upon a time” the advice was to trim often and trim hard. Now it is to trim as little as possible and ideally to help your flock by selecting sheep with good feet and legs. This latest advice is much kinder to the sheep (and the sheep keeper’s back we might add).
Many vets run foot trimming courses and it is well worth going on one. And in many multi-vet practices there is usually one vet who is a “foot expert” or at least the most interested in sheeps’ feet – a contact worth cultivating.
Scald (inflammation between the digits often caused by long or wet grass, mud, or dirty bedding in sheep housing) can affect lambs and adult sheep. As the bacteria causing scald are from the same family as those that cause foot-rot it is best to treat it as soon as possible.
Foot-rot is a serious condition and can result in needing to cull sheep that do not respond to treatment – both for that sheep’s welfare and to avoid spreading the infection. Dealing with foot-rot effectively requires advice from your vet.
When lambs are not thriving and / or have dirty rear ends, people’s first thought is often “worm burden”. But the cause can also be Coccidiosis. The only sure way to know is to take faecal samples and have your vet analyse them – for worms and coccidia.
Coccidia are single-celled, microscopic parasites that live and reproduce in animal cells. On pasture and in buildings the coccidia oocysts (eggs) are very hardy and can survive for long periods including over winter. They are resistant to drying, freezing, heat and many disinfectants. Older sheep usually have built up an immunity but can still shed low numbers of oocysts which can initiate infection even on clean pasture and in buildings.
It is in lambs that the disease is most dangerous. Lambs take in pathogenic coccidia oocysts (eggs) by mouth. Inside the gut, the oocysts hatch, invade the gut cells and multiply dramatically. The coccidia emerge by bursting the cells open – damaging the inside lining of the lamb’s gut. A dramatic number of oocysts are shed in faeces and this can be many million times higher than the number that were ingested. It takes two to three weeks from infection via the mouth to passing oocysts in faeces.
There are two aspects to preventing clinical coccidiosis – environment and licenced treatment.
At pasture, contamination levels are reduced by regularly moving to clean grazing and avoiding fields that carried young lambs in the previous season when possible. Lambs with ewes at lower stocking densities have a much lower risk of disease. Areas around creep or fodder feeders can become heavily contaminated and should be moved onto fresh ground daily.
In buildings, feeding troughs, water buckets and all equipment needs to be regularly cleaned with an effective disinfectant and bedding kept clean and fresh.
For treatment or for prevention, there are three licensed ingredients – diclazuril (e.g. Vecoxan), toltrazuril (e.g.Baycox, Toltranil and Cavezuril) and decoquinate (e.g. Decoxx). The first two are given by oral drench, the third as an additive to feed or an additive to mineral licks.
Johne’s Disease –
Johne’s is a bacterial disease. Multiplication of this bacteria within the wall of the intestine causes damage that leads to protein loss and thus weight loss and ill thrift. Affected sheep remain bright with a good appetite but will progressively lose condition until they die or are culled.
The disease has a long incubation period extending from months to years. Young lambs are most at risk of infection but symptoms may only develop several years later. Infected, but apparently healthy, animals will periodically shed the Johne’s disease bacteria in their faeces. This contaminates the environment where the bacteria can survive for up to 12 months if the conditions are right. Depending on the strain type, sheep can infect cattle and vice versa.
Screening healthy sheep to confirm infection with Johne’s disease can be challenging. There is no perfect test for this disease. The long incubation period means that repeated annual screening of a flock is required to prove freedom from Johne’s disease. Investigation of ill thriven animals is also important.
A vaccine is available which will reduce the effects of, but not eliminate, Johne’s disease from a flock. Vaccinated sheep will however test positive in the blood test.
SRUC run a Johne’s Accreditation Scheme as part of the Premium Sheep and Goat Health Schemes.
Enzootic Abortion of Ewes (EAE) –
Enzootic Abortion of Ewes (EAE) ranks as one of the most common causes of abortion in sheep in the UK. The disease can spread rapidly in intensively managed systems. Once established, the infection is persistent and difficult to eradicate. EAE is also a human health hazard which can pose a serious threat to pregnant women.
EAE can cause abortion storms and lamb loss leading to large economic loss.
Unfortunately it is a difficult disease to control for the following reasons:
- Infected ewes show no signs of ill health so you could be buying in disease without realising. Animals that have been infected in one lambing season can abort on your farm in the following spring. It won’t be until lambing time when it’s too late that your ewes will either abort 2 or 3 weeks before lambing is due to start or give birth to weak non-viable lambs.
- Once EAE infection is established within a flock it is persistent and difficult to eradicate. Following an abortion, ewes will lamb normally in subsequent years. However, these ewes are disease carriers and may infect their own lambs and any other sheep that they are in contact with.
SRUC run a EAE Accreditation Scheme as part of the Premium Sheep and Goat Health Schemes.
It is thought 90% of all sheep flocks in the UK have been exposed to the parasite Toxoplasma gondii, which can cause miscarriages, stillbirths and weak lambs.
If the parasite infects a pregnant ewe for the first time, it can cause disease in the placenta and the developing foetus. Any infection early on in pregnancy may cause foetal absorption, stillbirth, a mummified foetus or the birth of a live but weak lamb.
Infected ewes may also produce a live lamb alongside a weak, dead, or mummified twin lamb. The earlier in pregnancy that infection occurs, the more severe the consequences and there can be lots of empty ewes at scanning time if a flock of naïve, in-lamb ewes encounter toxoplasma for the first time.
Once infected animals develop immunity and so may lamb normally in subsequent years.
Sheep pick up the toxoplasma parasite readily from the environment by ingesting oocytes (parasite eggs) on pasture or in contaminated feed and water. Cats and members of the cat family are the definitive hosts of the parasite.
Toxoplasmosis can be controlled. Vaccination of the whole flock is the gold standard, but vaccinating young replacement ewes before they go to the tup for the first time should be the priority. Vaccination is known to protect ewes for at least two lambing seasons and many flocks just vaccinate the youngest age group of ewes each year. Breeding female sheep should all be vaccinated between four months and three weeks before tupping. Ewe lambs must be aged over five months for their first vaccination.
Toxoplasma may also be transmitted to humans from the ingestion of oocysts. Pregnant women should avoid contact with sheep.
Vaccine and drug transportation, storage and use –
Many vets now offer Use of Medicines courses that are recommended for Farm Assurance. This will cover aspects like storage, safety and correct usage of drugs. This is especially important in this era when all farmers are under pressure to minimise anti-biotic use wherever possible.
This snippet from one course shows that we can always learn something new –
Whenever you’re collecting drugs or vaccines from your vet or storing them on your holding, always make sure to follow the recommended storage guidelines. Otherwise the efficiency of the drug or vaccine may be impaired.
This may sound like obvious advice but, for example, if a vaccine requires storage at 2-5 degrees C, then it needs to be in your fridge – easy. But it also needs to be kept cold when you collect it from your vet and take it to use on your flock. A car dashboard in the sun for two hours is not going to be ideal even if you put the vaccine in the fridge when you get home! A thermal bag (sometimes provided by drug manufacturers, or an insulated lunch bag works too) is the thing to use.