Toxoplasmosis in Sheep
Toxoplasmosis is one of the leading causes of devastating abortion storms and can cause crippling
losses across breeding ewes.
In susceptible breeding ewes this disease can causes abortions, stillbirths and neonatal deaths.
Vaccinating is essential and having a well-timed vaccination plan in place reduces the risk and
consequences of potential large-scale losses.
Susceptible sheep become infected with Toxoplasma by ingesting the oocysts excreted in cat faeces.
These oocysts can be found in contaminated feed, bedding, pasture and water which can remain
infections for long periods.
The risk of Toxoplasma is highest in maiden ewes, hoggets and two-tooths but it can still affect
mixed age ewes. Any ewe that contracts Toxoplasmosis for the first time while she is pregnant is
likely to lose her lamb/s.
Research indicates that ewes infected with Toxoplasma in early gestation experience fetal death and resorption. This is often mistaken for ewe infertility and results in the unnecessary culling of
otherwise fertile animals. Ewes infected in mid-gestation or later are likely to abort, or give birth to
stillborn or weak lambs that fail to thrive.
Toxoplasmosis costs you in three ways:
- The loss of lambs by abortion; either by low-level unseen losses, or large-scale abortion
- The birth of weak lambs, which fail to thrive, or die
- The culling of fertile ewes, which because of undetected early abortion are presumed barren
Research has shown Toxoplasmosis has been present on 100% of New Zealand sheep farms. Every
sheep flock can be affected by ongoing insidious fetal losses and abortion storms.
Toxovax is a single dose vaccine that provides breeding ewes with lifetime protection against the
effects of Toxoplasmosis. Vaccination with Toxovax increases lambing percentage by an average of
3% and decreases the incidence of dry ewes by an average of 13%.
Toxovax is a live vaccine, has a short shelf life and is made to order. Please order your Toxovax from
your vet at least three weeks before you need to use it, which should be at least 8 weeks before
mating, to ensure supply.