Portland Sheep Breeders' Group
'The most popular rare breed for smallholders'
Regular Health Tasks
Below are a few of the more common tasks and problems.
Worming
How often you worm very much depends on the stocking density on the land, whether the land has had sheep on in the past, where the sheep came from and what other animals have grazed the land. Mixed grazing by cattle/horses and sheep, either simultaneously or in rotation will tend to reduce the parasite challenge for both species since each species eats parasite larvae indiscriminately, but only the larvae specific to the host species can usually survive.
In recent years there has been evidence of increasing worm resistance to anthelmintics and there has been a change in the general advice given. More and more animal keepers are taking faecal egg counts to assess flock burden and the type of worm/worms to be treated. Good up to date information can be obtained from www.scops.org.uk. It is also a good idea to consult with your vet who will help you devise a programme that is suitable for your sheep and the area you live in.
Foot Care
Sheep’s feet need checking regularly and if overgrown given a light trimming taking care to leave sufficient wall to take the weight of the sheep. Most outbreaks of lameness in sheep are caused by either interdigital dermatitis (scald) or footrot.
Individual cases of scald, often associated with lush growth of grass, can be treated using oxytetracycline aerosol spray. If many animals are affected a solution of either 10% zinc sulphate or 3% formalin in a footbath provides a good means of control.
Footrot can be treated with an injection of long acting antibiotic together with removal of debris from the foot and an application of anti-bacterial spray. However, the bacteria responsible for footrot can persist in the soil and cause constant re-infection. If this is the case it may be necessary to talk to your vet about vaccinating.
Current advice from sheep vets suggest less, rather than more feet trimming, to reduce cases of induced lameness and infection. Inspect the feet and consider what is needed before proceeding to trim.
Flystrike
Flystrike is caused by the sheep blowfly which usually lays its eggs in damp or dirty fleece, however if the atmospheric conditions are favourable even clean sheep are at risk. Any sheep with an open wound, e.g. from rubbing on a fence, are particularly vulnerable. Vigilance is needed throughout the high-risk months. When the maggots hatch they burrow into the flesh injecting a toxin into the wounds which will send the sheep into shock and death if not treated in time.
Affected sheep are often on their own, restless, with head looking back. They may bite, kick or rub at the struck area. On closer examination the wool overlying struck areas may be discoloured, moist and foul smelling, even if this is not the case take the time to part the wool down to the skin. Flystrike is always better caught early and before too much damage has occurred. 80% of flystrikes occur on the breech so crutching is beneficial.
Prior to shearing the sheep are very vulnerable to strike but it should be noted that the application of insecticide formulations can spoil fleeces which are to be processed. After shearing the sheep is safe until the wool has grown a few centimetres, then a preventative spray such as Clik, Vetrazin or Crovect can be applied.
Vaccinations
Some breeders use a programme of vaccination against many of the common diseases including the Chlostridials and Pasturella. The most commonly used product is Heptavac P+. After the initial two injections, 4-6 weeks apart, only an annual booster is required which is usually given 4 weeks before a ewe lambs, so that the protection will be passed temporarily on to her offspring. Around 3 to 4 weeks after birth give new lambs their own injection, then a booster some 4 weeks later, then into the flock cycle annually.
Schmallenberg Virus
This is transmitted by biting midges. In sheep the virus causes abnormalities in animals born alive or dead at term or aborted. Malformations include bent limbs, fixed joints, twisted neck or spine and domed appearance to the skull. Some are born with an outwardly normal appearance but may be blind or suffer from fits. The foetal deformities vary depending on when the infection occurred during pregnancy.
Have a chat with your vet regarding the climatic conditions when you start Tupping, depending on the weather the midges may or not be more prevalent. Then you can have a chat regarding the latest treatment or vaccine for this disease.
Orf
ORF is a highly contagious disease primarily of sheep and goats, caused by a parapox virus. People working with infected sheep can also catch ORF
The virus causes pustules and scabby lesions to develop normally around the nose and mouth. Minor abrasions of the skin are required to establish infection, so flocks kept on rough grazing - or on pasture with a high proportion of thistles - can be particularly prone to the disease. It is highly contagious so sheep should be quarantined when they have it, but it will clear in around 3 to 4 weeks without the requirement of treatment.
Ovine Pulmanory Adenocarcinoma (OPA)
Also known as ‘Wheelbarrow disease’ or ‘Jaagsiekte’, because if you pick up the hind legs of the sheep in the air, fluid is often observed running from the nose and mouth.