Salmonella remains an important disease risk on Irish farms, affecting both animal health and farm profitability.

The most common clinical signs of salmonellosis in cattle are diarrhoea and abortion, with Salmonella Typhimurium commonly associated with diarrhoea and Salmonella Dublin a major cause of abortion.

Following infection, cattle may recover and develop immunity, but some animals can become carriers. These carrier animals can continue to shed Salmonella bacteria either continuously, intermittently, or remain as hidden (latent) carriers, allowing infection to persist within a herd.

The impact of Salmonella goes beyond treatment costs and animal losses. Infection can have significant long-term effects on productivity and profitability, including:

Production losses may include:

• Reduced milk yield
• Fewer calves produced per cow per year
• Reduced daily weight gain
• Poor thrive and reduced performance

Protecting Your Herd Before the Risk Period

Salmonella Dublin abortions in spring-calving dairy herds typically begin to increase in autumn, with cases often peaking around November. To ensure adequate protection, pregnant heifers should receive their primary vaccination course, or a booster vaccination, at least 2–3 weeks before this higher-risk period.

Bovilis® Bovivac S Vaccination Protocol

Cattle aged 6 months to adult:

• Two 5ml doses given 21 days apart
• Annual booster vaccination recommended 2–3 weeks before the main risk period (typically around September)

Calves from approximately 3 weeks to 6 months:

• Primary vaccination course of two 2ml doses, 21 days apart

Vaccination should form part of a wider Salmonella control plan, alongside good hygiene, biosecurity measures, and effective herd management practices. Together, these measures help reduce the risk of infection and protect herd health.

Protect Your Herd. Protect Your People.

Talk to our farm team today about creating a Salmonella vaccination plan for your herd.