Toxoplasmosis and Campylobacteriosis in Sheep
Risks, Impacts, and the Benefits of Vaccination with Toxovax® and Campyvax®
Reproductive losses are one of the most costly and frustrating challenges in sheep production. Two of the most important and preventable causes of abortion and poor lambing performance in New Zealand flocks are toxoplasmosis and campylobacteriosis. Both diseases are widespread, often underdiagnosed, and capable of causing significant hidden losses long before an abortion storm becomes obvious.
Vaccination with Toxovax® and Campyvax® is a proven and cost-effective strategy to protect ewe fertility, lift lambing percentages, and improve flock productivity.
Toxoplasmosis in Sheep
What Is Toxoplasmosis?
Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii, which is shed in the faeces of cats. Sheep become infected by ingesting contaminated pasture, silage, hay, grain, or water.
Once introduced, toxoplasmosis often becomes a persistent farm problem, as oocysts survive in the environment for long periods.
Effects on Reproduction
The impact of infection depends on the stage of pregnancy:
Early pregnancy: Embryonic loss and reabsorption, resulting in dry ewes or late lambers
Midpregnancy: Abortion, mummified foetuses
Late pregnancy: Stillbirths or weak lambs that die soon after birth
Without vaccination, toxoplasmosis can cause abortion rates of 30–50% in naïve flocks during outbreaks.
Campylobacteriosis in Sheep
What Is Campylobacteriosis?
Campylobacteriosis is a bacterial disease caused mainly by Campylobacter fetus fetus and Campylobacter jejuni. The organisms are spread through contaminated feed, water, aborted material, and direct contact between sheep.
Many ewes become silent carriers, allowing infection to persist on farms for years.
Effects on Reproduction
Campylobacter infection can cause:
Early embryonic loss (dry ewes or poor scanning results)
Lateterm abortions
Stillbirths
Weak, nonviable lambs
Abortion storms can result in lamb losses of up to 30% in susceptible flocks.
Benefits of Vaccination
Why Vaccinate?
Management strategies alone are often insufficient once these diseases are established. Vaccination provides reliable, flockwide protection and prevents both visible abortion storms and hidden reproductive losses.
Toxovax® – Protection Against Toxoplasmosis
Key Benefits
Singleshot vaccination provides longlasting immunityProtects against abortion storms
Average 3% increase in lambing percentage
Significant reduction in dry ewes
Dosage and Administration
Dose: 2 mL per ewe
Route: Intramuscular (IM) injection
Schedule:
Single dose at least 3–4 weeks before mating
Only for nonpregnant ewes
Booster: Not required in most systems (long-duration immunity)
Important Safety Notes
Do not vaccinate pregnant ewes
Live vaccine – special care required during handling
Not to be handled by pregnant women or immunocompromised persons
Campyvax® – Protection Against Campylobacteriosis
Key Benefits
Prevents abortion and perinatal losses
Improves scanningtomarking performance
Increases lambing percentage by an average of up to 9%, even on farms without obvious abortions
Reduces the impact of hidden reproductive losses
Dosage and Administration
Dose: 1 mL per ewe (NZ Campyvax®4 formulation)
Route: Subcutaneous (SC) injection in the neck
Primary Course:
Two doses 4–8 weeks apart, completed before mating
Booster:
Annual booster prior to each mating season
Bringing It Together: A Practical Vaccination Strategy
Most NZ sheep systems benefit from using both vaccines, as toxoplasmosis and campylobacteriosis often occur together and cause overlapping production losses.
Typical premating plan:
Maiden and mixed-age ewes:
Toxovax®: once (nonpregnant, prior to mating)
Campyvax®: two-dose primary, then annual boosters
Conclusion
Toxoplasmosis and campylobacteriosis remain two of the leading infectious causes of reproductive failure in sheep. Because losses often occur silently, vaccination is best viewed as productivity insurance rather than outbreak control.
Strategic use of Toxovax® and Campyvax® results in fewer dry ewes, more lambs on the ground, and stronger flock performance year after year.
For more information, please visit sheepvax.co.nz.
