Abortions in sheep and goats are often misinterpreted, potentially compromising both productivity and animal and human health. C. abortus is an important infectious agent, and underestimating the disease can have serious consequences. In this article, we debunk myths about abortions in small ruminants.
Myth 1: “If a sheep aborts, it doesn’t matter, it’s an isolated case”
Reality: it is true that a certain percentage of reproductive losses (<5%) is considered normal, but cases of abortion should always alert us and a thorough diagnosis should be carried out.
C. abortus usually manifests in the form of outbreaks, but can also cause sporadic abortions in endemic flocks.
Myth 2: “Abortions only occur in large flocks”
Reality: All flocks are at risk. Introducing a single animal carrying C. abortus into the flock can be enough to trigger an outbreak. The impact of the infection will depend on the management, biosafety and preventive measures implemented.
Myth 3: “If I don’t see any symptoms in the sheep, there’s no infection”
Reality: Females infected by C. abortus remain asymptomatic until the time of abortion, due to the latent state of the pathogen. From day 90 of gestation, hormonal changes activate Chlamydia, allowing it to invade the placenta.
The lack of visible symptoms does not mean that the flock is free of infection.
Myth 4: “Once the flock is infected, it becomes immune”
Reality: Infected animals that abort develop an immune response against the pathogen, but this natural immunity is neither complete nor long-lasting. Once infected, animals are chronic carriers, capable of transmitting the infection.
Myth 5: “Abortions only affect the animals, people are not at risk”
Fact: C. abortus is a zoonotic agent and can be transmitted from animals to people. The risk is especially high for pregnant women, who may suffer serious complications if they come into contact with infected animals, placentas or secretions.
Myth 6: “Vaccination is not effective because the animals have already been exposed”
Fact: Although vaccines are a preventative tool, their use is key to reducing the magnitude of outbreaks and protecting susceptible animals. Even in flocks infected with C. abortus, vaccination helps control the spread of the pathogen and minimise the impact on reproduction.
Conclusions
Underestimating abortion-causing diseases can delay the adoption of appropriate measures and worsen the economic impact. Health surveillance, biosafety measures, and annual vaccination are the basis of an effective strategy for preserving flock health.
Article written by:
Tania Perálvarez Puerta. Global Product Manager, Small Ruminants Franchise – HIPRA
