Orf vaccination; how to get the most out of vaccinating your sheep

Orf vaccination; how to get the most out of vaccinating your sheep


This video aims to give sheep farmers advice
on orf vaccination, by highlighting key issues, such as which sheep to vaccinate, when to
vaccinate, and how to vaccinate effectively. The most recent UK study into Orf estimated
that 20 percent of lambs are affected by Orf. Vaccination is available in the form of a
live vaccine and because it is a live attenuated virus vaccine, it should only be used on farms
where orf is a problem. The aim of the vaccine is to reduce clinical signs and lesions, such
as scabs and pustules. It is important to remember that a vaccine
works very differently to an antibiotic or any other medicine; it does not kill the virus,
but triggers an immune response from the animal, protecting it from future infection, or helps build a better immune response to
current infection. Orf infection is a virus that causes scabs
and pustules to develop around the mouth and nose of sheep, making suckling, eating and
drinking difficult and painful. This has been shown to cause slower growth rates in lambs.
It can also cause mastitis in ewes due to infected lambs suckling their mothers, leading
to increased ewe replacement rates. Correct storage is crucial for the live orf
vaccine as it ensures efficacy and good value for money. The vaccine should be kept between
2-8 degrees celsius, during both storage and use, which can be achieved by storing the vaccine in
a working fridge and using a max-min thermometer inside the fridge to monitor the temperature.
When the vaccine is out of the recommended temperature zone, its efficacy drops, as there
is live but weakened virus in the vaccine, which will not provide good protection if
it dies before it gets into the animal. A recent study showed that the majority of
farm fridges failed to keep any stored vaccine within the recommended storage temperature
range, which means that your vaccine is unlikely to work when you use it (Williams and Paixão,
2018). In addition, storage time after opening a
bottle is important; a study carried out at Nottingham University showed that orf vaccine
was used by many farmers beyond the time limit of 8 hours from opening a vaccine bottle.
Using orf vaccine more than a day after opening, is unlikely to have any beneficial effect
on your sheep, which means wasting both your time and money. Both lambs and ewes can be vaccinated against
Orf to reduce clinical signs of the disease. Lambs are recommended to be vaccinated at
1 to 3 days old. The vaccine comes in a 50-dose bottle, so although vaccinating at 1 to 3
days old is ideal, batch vaccinating after approx. 50 lambs are born, is an acceptable
practical approach. Ewes should be vaccinated more than 7 weeks
prior to lambing or moving to lambing areas, as vaccinating closer to lambing or moving
may expose new-born lambs to the scabs that form on the ewes as a vaccine response, and
lambs may get infected that way. A study carried out at Nottingham University
showed that many farmers worry that they can ‘make things worse’ by using the live
vaccine, however if Orf infection is already in your flock, there is no evidence to suggest
that vaccinating will make the problem worse. Vaccination will reduce the lesions that cause
the reduced growth rates and discomfort in your sheep. It is important to know that orf
vaccine is an attenuated vaccine, which means the live virus it contains is made less virulent
and therefore won’t cause disease in your sheep provided it is used correctly and only
on healthy animals that aren’t immunocompromised. Avoid treatment of sheep with other products
such as immunosuppressive drugs, disinfectants, sprays or dips within 7 days before or after
administration of orf vaccine. Lambs should be scratched under the armpit,
in a firm swipe of 4-5cm, with enough pressure to break the skin but not to draw blood. This
demonstration illustrates how firm you can be. After a few attempts, which you can practice
using a banana, the amount of pressure you need to only break the skin and not draw blood
becomes apparent. Some farmers are concerned about catching
Orf while vaccinating, as Orf is a zoonosis that can be passed from sheep to humans. However,
if you are using the correct method, this risk is negligible for almost everyone, except
immune suppressed individuals. Everyone needs to wear gloves while vaccinating and make
sure to wash their hands after vaccination. Checking your sheep to see if the vaccine
has ‘taken’ will confirm if your sheep are effectively vaccinated. You should check
the vaccination site around a week after vaccination, to see if a line of pustules has developed
along the scratch line. This indicates a positive vaccine response as is being shown in the
photo on the left, compared to a negative response, shown by the photo on the right. We recommend you discuss an Orf vaccination
scheme with your vet who can help on any points which you are unsure of. The data sheet, or
Summary of Product Characteristics, that comes with the vaccine can also be found online and contains all the information about the vaccine. Many vets can provide a summary of
the key points of this datasheet that are specifically relevant to your situation. There are several good resources listed here
if you are looking for further information around orf; we hope this video has helped
you to optimise the health, performance, and productivity of your flock.

Add a Comment

Your email address will not be published. Required fields are marked *