Enzootic abortion (Chlamydia) and toxoplasma are among the most common causes of infectious abortion in ewes. Vaccines are available for both, and it is a good idea to vaccinate now, particularly for early lambers.
Given to ewe-lambs from 5 months of age, or to shearlings and older ewes 4 months – 4 weeks prior to tupping. The vaccine is not safe to use in pregnant sheep. The following year after vaccination, you will only need to vaccinate your ewe-lambs plus any bought in sheep.
Vaccination protects against abortion and also reduces the number of Chlamydia shed at lambing. Vaccinating ewes infected the previous lambing season (i.e. latent carriers) reduces the abortion rate in these ewes by about 50%.
Toxoplasma gondii is now the world’s most common parasite and it’s been estimated that over 90% of sheep flocks in Great Britain are exposed to it. The complex Toxoplama gondii parasite lifecycle presents significant disease management challenges because the sheer volume of infectious oocysts produced by the parasite and their resistance to destruction leads to widespread environmental contamination. If you are not already vaccinating against toxoplasmosis it’s probably only a matter of time before new ewes succumb to an infection, so you should plan ahead accordingly. Certainly, if you had more than 2% of your flock aborting during this season, your primary focus should be on preventing infection in pregnant ewes in the first place, and the best way to do that is to vaccinate replacement ewes well before they go to the ram.
Toxovax is given to ewe-lambs from 5 months of age and ewes 4 months – 3 weeks before tupping so again, vaccinating now is recommended. As with CEVAC Chlamydia, many farmers choose to only vaccinate new stock the following year, although the vaccine manufacturers do recommend a booster every 2 years.