News & Advice

Is your herd protected against Salmonella?

Jun 2, 2020 | Biosecurity, Dairy, Dairy Animal Health & Welfare

Outbreaks of Salmonella often arise during the winter due to the additional stresses our cattle face during this period. So, with winter upon us, now is the perfect time to get clued up on what salmonella is, what to look out for and what you can do about it! 

What Exactly is Salmonella? 

Salmonella is the bacteria which causes the disease known as salmonellosis. It is typically contracted from environments, water and feedstuffs contaminated with faeces from infected animals, some of which may be carriers and showing no obvious clinical signs. Other species can also be responsible for spread, particularly birds and rodents. Salmonella can also be passed on to humans (i.e. is a zoonosis) and can result in significant illness. 

What does an Animal with Salmonella look like? 

Salmonella can have many different presentations from an asymptomatic carrier animal to animals that you simply find dead! We sometimes see individual animals affected or we can see farms experiencing severe outbreaks affecting many animals at the same time.
Commonly you might initially notice a cow that isn’t eating well, is off her milk and that is a bit slower than usual. This can then swiftly progress to profuse, foul-smelling diarrhoea which may contain blood, mucus or shreds of intestinal lining. These animals will become severely dehydrated very quickly and can die if not treated promptly. Salmonella can also be a cause of abortion in cattle. If you suspect you have a cow with salmonella, isolate her immediately (it can be highly contagious) and get in contact with your vet. 

What Can I do to Control and Prevent Outbreaks? 

  • Isolate sick animals  to reduce environmental contamination. 
  • Avoid introducing infected animals:  Bringing new stock onto the farm can introduce disease. If you don’t run a closed herd then it is vital to have a quarantine protocol for these animals so they can be brought into your herd safely. 
  • Effluent management:  Ideally avoid grazing effluent paddocks and don’t use effluent to irrigate pastures as this will greatly increase the number of animals exposed to the bacteria. 
  • Pest control to reduce contamination  of feed and water. 
  • Manage nutrition:  Cases of salmonella can be associated with a sudden diet change, feed shortages or
    over-supplementation with some types of magnesium oxide. 
  • Maintaining good hygiene practices:  Ensuring you and your equipment is clean and disinfected will not only reduce spread but also protect yourself from contracting salmonella. It is a good idea to wear gloves when dealing with sick animals, wash your hands thoroughly and avoid drinking unpasteurised milk. 
  • Consider vaccination:  Vaccination is a helpful tool in preventing or reducing the severity of outbreaks. Animals will require two shots initially and then annual boosters which when administered late in pregnancy can also provide new born calves with colostral antibodies for salmonella. 

Anecdotally, as we are seeing more herds affected each season, vaccination can be an affordable insurance policy. If you want to discuss a prevention and vaccination plan or are worried that you may have a case of Salmonella on farm then please don’t hesitate to get in touch with your local Anexa Vet, we’re here to help!

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